virtio-mem
doorbell mapping for vdpa
config interrupt support in ifc
fixes all over the place
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
Pull virtio updates from Michael Tsirkin:
- virtio-mem: paravirtualized memory hotplug
- support doorbell mapping for vdpa
- config interrupt support in ifc
- fixes all over the place
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (40 commits)
vhost/test: fix up after API change
virtio_mem: convert device block size into 64bit
virtio-mem: drop unnecessary initialization
ifcvf: implement config interrupt in IFCVF
vhost: replace -1 with VHOST_FILE_UNBIND in ioctls
vhost_vdpa: Support config interrupt in vdpa
ifcvf: ignore continuous setting same status value
virtio-mem: Don't rely on implicit compiler padding for requests
virtio-mem: Try to unplug the complete online memory block first
virtio-mem: Use -ETXTBSY as error code if the device is busy
virtio-mem: Unplug subblocks right-to-left
virtio-mem: Drop manual check for already present memory
virtio-mem: Add parent resource for all added "System RAM"
virtio-mem: Better retry handling
virtio-mem: Offline and remove completely unplugged memory blocks
mm/memory_hotplug: Introduce offline_and_remove_memory()
virtio-mem: Allow to offline partially unplugged memory blocks
mm: Allow to offline unmovable PageOffline() pages via MEM_GOING_OFFLINE
virtio-mem: Paravirtualized memory hotunplug part 2
virtio-mem: Paravirtualized memory hotunplug part 1
...
We can now handle sysctl parameters on kernel command line, but
historically some parameters introduced their own command line
equivalent, which we don't want to remove for compatibility reasons.
We can, however, convert them to the generic infrastructure with a table
translating the legacy command line parameters to their sysctl names,
and removing the one-off param handlers.
This patch adds the support and makes the first conversion to
demonstrate it, on the (deprecated) numa_zonelist_order parameter.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Guilherme G . Piccoli" <gpiccoli@canonical.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Ivan Teterevkov <ivan.teterevkov@nutanix.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200427180433.7029-3-vbabka@suse.cz
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
virtio-mem wants to allow to offline memory blocks of which some parts
were unplugged (allocated via alloc_contig_range()), especially, to later
offline and remove completely unplugged memory blocks. The important part
is that PageOffline() has to remain set until the section is offline, so
these pages will never get accessed (e.g., when dumping). The pages should
not be handed back to the buddy (which would require clearing PageOffline()
and result in issues if offlining fails and the pages are suddenly in the
buddy).
Let's allow to do that by allowing to isolate any PageOffline() page
when offlining. This way, we can reach the memory hotplug notifier
MEM_GOING_OFFLINE, where the driver can signal that he is fine with
offlining this page by dropping its reference count. PageOffline() pages
with a reference count of 0 can then be skipped when offlining the
pages (like if they were free, however they are not in the buddy).
Anybody who uses PageOffline() pages and does not agree to offline them
(e.g., Hyper-V balloon, XEN balloon, VMWare balloon for 2MB pages) will not
decrement the reference count and make offlining fail when trying to
migrate such an unmovable page. So there should be no observable change.
Same applies to balloon compaction users (movable PageOffline() pages), the
pages will simply be migrated.
Note 1: If offlining fails, a driver has to increment the reference
count again in MEM_CANCEL_OFFLINE.
Note 2: A driver that makes use of this has to be aware that re-onlining
the memory block has to be handled by hooking into onlining code
(online_page_callback_t), resetting the page PageOffline() and
not giving them to the buddy.
Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Tested-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Anthony Yznaga <anthony.yznaga@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Pingfan Liu <kernelfans@gmail.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20200507140139.17083-7-david@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
We also want to unplug online memory (contained in online memory blocks
and, therefore, managed by the buddy), and eventually replug it later.
When requested to unplug memory, we use alloc_contig_range() to allocate
subblocks in online memory blocks (so we are the owner) and send them to
our hypervisor. When requested to plug memory, we can replug such memory
using free_contig_range() after asking our hypervisor.
We also want to mark all allocated pages PG_offline, so nobody will
touch them. To differentiate pages that were never onlined when
onlining the memory block from pages allocated via alloc_contig_range(), we
use PageDirty(). Based on this flag, virtio_mem_fake_online() can either
online the pages for the first time or use free_contig_range().
It is worth noting that there are no guarantees on how much memory can
actually get unplugged again. All device memory might completely be
fragmented with unmovable data, such that no subblock can get unplugged.
We are not touching the ZONE_MOVABLE. If memory is onlined to the
ZONE_MOVABLE, it can only get unplugged after that memory was offlined
manually by user space. In normal operation, virtio-mem memory is
suggested to be onlined to ZONE_NORMAL. In the future, we will try to
make unplug more likely to succeed.
Add a module parameter to control if online memory shall be touched.
As we want to access alloc_contig_range()/free_contig_range() from
kernel module context, export the symbols.
Note: Whenever virtio-mem uses alloc_contig_range(), all affected pages
are on the same node, in the same zone, and contain no holes.
Acked-by: Michal Hocko <mhocko@suse.com> # to export contig range allocator API
Tested-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Alexander Potapenko <glider@google.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20200507140139.17083-6-david@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Merge more updates from Andrew Morton:
"More mm/ work, plenty more to come
Subsystems affected by this patch series: slub, memcg, gup, kasan,
pagealloc, hugetlb, vmscan, tools, mempolicy, memblock, hugetlbfs,
thp, mmap, kconfig"
* akpm: (131 commits)
arm64: mm: use ARCH_HAS_DEBUG_WX instead of arch defined
x86: mm: use ARCH_HAS_DEBUG_WX instead of arch defined
riscv: support DEBUG_WX
mm: add DEBUG_WX support
drivers/base/memory.c: cache memory blocks in xarray to accelerate lookup
mm/thp: rename pmd_mknotpresent() as pmd_mkinvalid()
powerpc/mm: drop platform defined pmd_mknotpresent()
mm: thp: don't need to drain lru cache when splitting and mlocking THP
hugetlbfs: get unmapped area below TASK_UNMAPPED_BASE for hugetlbfs
sparc32: register memory occupied by kernel as memblock.memory
include/linux/memblock.h: fix minor typo and unclear comment
mm, mempolicy: fix up gup usage in lookup_node
tools/vm/page_owner_sort.c: filter out unneeded line
mm: swap: memcg: fix memcg stats for huge pages
mm: swap: fix vmstats for huge pages
mm: vmscan: limit the range of LRU type balancing
mm: vmscan: reclaim writepage is IO cost
mm: vmscan: determine anon/file pressure balance at the reclaim root
mm: balance LRU lists based on relative thrashing
mm: only count actual rotations as LRU reclaim cost
...
commit 3c710c1ad1 ("mm, vmscan extract shrink_page_list reclaim counters
into a struct") changed data type for the function, so changing return
type for funciton and its caller.
Signed-off-by: Vaneet Narang <v.narang@samsung.com>
Signed-off-by: Maninder Singh <maninder1.s@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Amit Sahrawat <a.sahrawat@samsung.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Link: http://lkml.kernel.org/r/1588168259-25604-1-git-send-email-maninder1.s@samsung.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add missing line breaks on pr_warn().
Signed-off-by: Chen Tao <chentao107@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200603063547.235825-1-chentao107@huawei.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Using padata during deferred init has only been tested on x86, so for now
limit it to this architecture.
If another arch wants this, it can find the max thread limit that's best
for it and override deferred_page_init_max_threads().
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Josh Triplett <josh@joshtriplett.org>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Robert Elliott <elliott@hpe.com>
Cc: Shile Zhang <shile.zhang@linux.alibaba.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Link: http://lkml.kernel.org/r/20200527173608.2885243-8-daniel.m.jordan@oracle.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Deferred page init used to report the number of pages initialized:
node 0 initialised, 32439114 pages in 97ms
Tracking this makes the code more complicated when using multiple threads.
Given that the statistic probably has limited value, especially since a
zone grows on demand so that the page count can vary, just remove it.
The boot message now looks like
node 0 deferred pages initialised in 97ms
Suggested-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Robert Elliott <elliott@hpe.com>
Cc: Shile Zhang <shile.zhang@linux.alibaba.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Link: http://lkml.kernel.org/r/20200527173608.2885243-6-daniel.m.jordan@oracle.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Initializing struct pages is a long task and keeping interrupts disabled
for the duration of this operation introduces a number of problems.
1. jiffies are not updated for long period of time, and thus incorrect time
is reported. See proposed solution and discussion here:
lkml/20200311123848.118638-1-shile.zhang@linux.alibaba.com
2. It prevents farther improving deferred page initialization by allowing
intra-node multi-threading.
We are keeping interrupts disabled to solve a rather theoretical problem
that was never observed in real world (See 3a2d7fa8a3).
Let's keep interrupts enabled. In case we ever encounter a scenario where
an interrupt thread wants to allocate large amount of memory this early in
boot we can deal with that by growing zone (see deferred_grow_zone()) by
the needed amount before starting deferred_init_memmap() threads.
Before:
[ 1.232459] node 0 initialised, 12058412 pages in 1ms
After:
[ 1.632580] node 0 initialised, 12051227 pages in 436ms
Fixes: 3a2d7fa8a3 ("mm: disable interrupts while initializing deferred pages")
Reported-by: Shile Zhang <shile.zhang@linux.alibaba.com>
Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Yiqian Wei <yiwei@redhat.com>
Cc: <stable@vger.kernel.org> [4.17+]
Link: http://lkml.kernel.org/r/20200403140952.17177-3-pasha.tatashin@soleen.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "initialize deferred pages with interrupts enabled", v4.
Keep interrupts enabled during deferred page initialization in order to
make code more modular and allow jiffies to update.
Original approach, and discussion can be found here:
http://lkml.kernel.org/r/20200311123848.118638-1-shile.zhang@linux.alibaba.com
This patch (of 3):
deferred_init_memmap() disables interrupts the entire time, so it calls
touch_nmi_watchdog() periodically to avoid soft lockup splats. Soon it
will run with interrupts enabled, at which point cond_resched() should be
used instead.
deferred_grow_zone() makes the same watchdog calls through code shared
with deferred init but will continue to run with interrupts disabled, so
it can't call cond_resched().
Pull the watchdog calls up to these two places to allow the first to be
changed later, independently of the second. The frequency reduces from
twice per pageblock (init and free) to once per max order block.
Fixes: 3a2d7fa8a3 ("mm: disable interrupts while initializing deferred pages")
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Shile Zhang <shile.zhang@linux.alibaba.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: James Morris <jmorris@namei.org>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Yiqian Wei <yiwei@redhat.com>
Cc: <stable@vger.kernel.org> [4.17+]
Link: http://lkml.kernel.org/r/20200403140952.17177-2-pasha.tatashin@soleen.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Restrict elements in compound_page_dtors[] array per NR_COMPOUND_DTORS and
explicitly position them according to enum compound_dtor_id. This
improves protection against possible misalignment between
compound_page_dtors[] and enum compound_dtor_id later on.
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Link: http://lkml.kernel.org/r/1589795958-19317-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Updating the zone watermarks by any means, like min_free_kbytes,
water_mark_scale_factor etc, when ->watermark_boost is set will result in
higher low and high watermarks than the user asked.
Below are the steps to reproduce the problem on system setup of Android
kernel running on Snapdragon hardware.
1) Default settings of the system are as below:
#cat /proc/sys/vm/min_free_kbytes = 5162
#cat /proc/zoneinfo | grep -e boost -e low -e "high " -e min -e Node
Node 0, zone Normal
min 797
low 8340
high 8539
2) Monitor the zone->watermark_boost(by adding a debug print in the
kernel) and whenever it is greater than zero value, write the same
value of min_free_kbytes obtained from step 1.
#echo 5162 > /proc/sys/vm/min_free_kbytes
3) Then read the zone watermarks in the system while the
->watermark_boost is zero. This should show the same values of
watermarks as step 1 but shown a higher values than asked.
#cat /proc/zoneinfo | grep -e boost -e low -e "high " -e min -e Node
Node 0, zone Normal
min 797
low 21148
high 21347
These higher values are because of updating the zone watermarks using the
macro min_wmark_pages(zone) which also adds the zone->watermark_boost.
#define min_wmark_pages(z) (z->_watermark[WMARK_MIN] +
z->watermark_boost)
So the steps that lead to the issue are:
1) On the extfrag event, watermarks are boosted by storing the required
value in ->watermark_boost.
2) User tries to update the zone watermarks level in the system through
min_free_kbytes or watermark_scale_factor.
3) Later, when kswapd woke up, it resets the zone->watermark_boost to
zero.
In step 2), we use the min_wmark_pages() macro to store the watermarks
in the zone structure thus the values are always offsetted by
->watermark_boost value. This can be avoided by resetting the
->watermark_boost to zero before it is used.
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Link: http://lkml.kernel.org/r/1589457511-4255-1-git-send-email-charante@codeaurora.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Initially, the per-cpu pagesets of each zone are set to the boot pagesets.
The real pagesets are allocated later but before that happens, page
allocations do occur and the numa stats for the boot pagesets get
incremented since they are common to all zones at that point.
The real pagesets, however, are allocated for the populated zones only.
Unpopulated zones, like those associated with memory-less nodes, continue
using the boot pageset and end up skewing the numa stats of the
corresponding node.
E.g.
$ numactl -H
available: 2 nodes (0-1)
node 0 cpus: 0 1 2 3
node 0 size: 0 MB
node 0 free: 0 MB
node 1 cpus: 4 5 6 7
node 1 size: 8131 MB
node 1 free: 6980 MB
node distances:
node 0 1
0: 10 40
1: 40 10
$ numastat
node0 node1
numa_hit 108 56495
numa_miss 0 0
numa_foreign 0 0
interleave_hit 0 4537
local_node 108 31547
other_node 0 24948
Hence, the boot pageset stats need to be cleared after the real pagesets
are allocated.
After this point, the stats of the boot pagesets do not change as page
allocations requested for a memory-less node will either fail (if
__GFP_THISNODE is used) or get fulfilled by a preferred zone of a
different node based on the fallback zonelist.
[sandipan@linux.ibm.com: v3]
Link: http://lkml.kernel.org/r/20200511170356.162531-1-sandipan@linux.ibm.com
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Link: http://lkml.kernel.org/r/9c9c2d1b15e37f6e6bf32f99e3100035e90c4ac9.1588868430.git.sandipan@linux.ibm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pageblock migrate type is encoded in GFP flags, just as zone_type and
zonelist.
Currently we use gfp_zone() and gfp_zonelist() to extract related
information, it would be proper to use the same naming convention for
migrate type.
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Link: http://lkml.kernel.org/r/20200329080823.7735-1-richard.weiyang@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Slightly simplify the code by initializing user_mask with NODE_MASK_NONE,
instead of later calling nodes_clear(). This saves a line of code.
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Link: http://lkml.kernel.org/r/20200330220840.21228-1-richard.weiyang@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
classzone_idx is just different name for high_zoneidx now. So, integrate
them and add some comment to struct alloc_context in order to reduce
future confusion about the meaning of this variable.
The accessor, ac_classzone_idx() is also removed since it isn't needed
after integration.
In addition to integration, this patch also renames high_zoneidx to
highest_zoneidx since it represents more precise meaning.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Baoquan He <bhe@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Ye Xiaolong <xiaolong.ye@intel.com>
Link: http://lkml.kernel.org/r/1587095923-7515-3-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When requesting memory allocation from a specific zone is not satisfied,
it will fall to lower zone to try allocating memory. In this case, lower
zone's ->lowmem_reserve[] will help protect its own memory resource. The
higher the relevant ->lowmem_reserve[] is, the harder the upper zone can
get memory from this lower zone.
However, this protection mechanism should be applied to populated zone,
but not an empty zone. So filling ->lowmem_reserve[] for empty zone is
not necessary, and may mislead people that it's valid data in that zone.
Node 2, zone DMA
pages free 0
min 0
low 0
high 0
spanned 0
present 0
managed 0
protection: (0, 0, 1024, 1024)
Node 2, zone DMA32
pages free 0
min 0
low 0
high 0
spanned 0
present 0
managed 0
protection: (0, 0, 1024, 1024)
Node 2, zone Normal
per-node stats
nr_inactive_anon 0
nr_active_anon 143
nr_inactive_file 0
nr_active_file 0
nr_unevictable 0
nr_slab_reclaimable 45
nr_slab_unreclaimable 254
Here clear out zone->lowmem_reserve[] if zone is empty.
Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200402140113.3696-3-bhe@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "improvements about lowmem_reserve and /proc/zoneinfo", v2.
This patch (of 3):
When people write to /proc/sys/vm/lowmem_reserve_ratio to change
sysctl_lowmem_reserve_ratio[], setup_per_zone_lowmem_reserve() is called
to recalculate all ->lowmem_reserve[] for each zone of all nodes as below:
static void setup_per_zone_lowmem_reserve(void)
{
...
for_each_online_pgdat(pgdat) {
for (j = 0; j < MAX_NR_ZONES; j++) {
...
while (idx) {
...
if (sysctl_lowmem_reserve_ratio[idx] < 1) {
sysctl_lowmem_reserve_ratio[idx] = 0;
lower_zone->lowmem_reserve[j] = 0;
} else {
...
}
}
}
}
Meanwhile, here, sysctl_lowmem_reserve_ratio[idx] will be tuned if its
value is smaller than '1'. As we know, sysctl_lowmem_reserve_ratio[] is
set for zone without regarding to which node it belongs to. That means
the tuning will be done on all nodes, even though it has been done in the
first node.
And the tuning will be done too even when init_per_zone_wmark_min() calls
setup_per_zone_lowmem_reserve(), where actually nobody tries to change
sysctl_lowmem_reserve_ratio[].
So now move the tuning into lowmem_reserve_ratio_sysctl_handler(), to make
code logic more reasonable.
Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: David Rientjes <rientjes@google.com>
Link: http://lkml.kernel.org/r/20200402140113.3696-1-bhe@redhat.com
Link: http://lkml.kernel.org/r/20200402140113.3696-2-bhe@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since commit 397dc00e24 ("mips: sgi-ip27: switch from DISCONTIGMEM
to SPARSEMEM"), the last caller of free_bootmem_with_active_regions() was
gone. Now no user calls it any more.
Let's remove it.
Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Link: http://lkml.kernel.org/r/20200402143455.5145-1-bhe@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently a cma area is barely used by the page allocator because it's
used only as a fallback from movable, however kswapd tries hard to make
sure that the fallback path isn't used.
This results in a system evicting memory and pushing data into swap, while
lots of CMA memory is still available. This happens despite the fact that
alloc_contig_range is perfectly capable of moving any movable allocations
out of the way of an allocation.
To effectively use the cma area let's alter the rules: if the zone has
more free cma pages than the half of total free pages in the zone, use cma
pageblocks first and fallback to movable blocks in the case of failure.
[guro@fb.com: ifdef the cma-specific code]
Link: http://lkml.kernel.org/r/20200311225832.GA178154@carbon.DHCP.thefacebook.com
Co-developed-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Qian Cai <cai@lca.pw>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Link: http://lkml.kernel.org/r/20200306150102.3e77354b@imladris.surriel.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We share similar code in check_[new|free]_page_bad() to get the page's bad
reason.
Let's extract it and reduce code duplication.
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Link: http://lkml.kernel.org/r/20200411220357.9636-6-richard.weiyang@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
free_pages_check() is the counterpart of check_new_page(). Rename it to
use the same naming convention.
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Link: http://lkml.kernel.org/r/20200411220357.9636-5-richard.weiyang@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
free_pages_check_bad() is the counterpart of check_new_page_bad(). Rename
it to use the same naming convention.
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Link: http://lkml.kernel.org/r/20200411220357.9636-4-richard.weiyang@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After commit 5b57b8f227 ("mm/debug.c: always print flags in
dump_page()"), page->flags is always printed for a bad page. It is not
necessary to have bad_flags any more.
Suggested-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Link: http://lkml.kernel.org/r/20200411220357.9636-3-richard.weiyang@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm/page_alloc.c: cleanup on check page", v3.
This patchset does some cleanup related to check page.
1. Remove unnecessary bad_reason assignment
2. Remove bad_flags to bad_page()
3. Rename function for naming convention
4. Extract common part to check page
Thanks for suggestions from David Rientjes and Anshuman Khandual.
This patch (of 5):
Since function returns directly, bad_[reason|flags] is not used any where.
And move this to the first.
This is a following cleanup for commit e570f56ccc ("mm:
check_new_page_bad() directly returns in __PG_HWPOISON case")
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: David Rientjes <rientjes@google.com>
Link: http://lkml.kernel.org/r/20200411220357.9636-2-richard.weiyang@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
find_min_pfn_with_active_regions() calls find_min_pfn_for_node() with nid
parameter set to MAX_NUMNODES. This makes the find_min_pfn_for_node()
traverse all memblock memory regions although the first PFN in the system
can be easily found with memblock_start_of_DRAM().
Use memblock_start_of_DRAM() in find_min_pfn_with_active_regions() and drop
now unused find_min_pfn_for_node().
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Hoan Tran <hoan@os.amperecomputing.com> [arm64]
Cc: Baoquan He <bhe@redhat.com>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200412194859.12663-21-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
free_area_init_node() now always uses memblock info and the zone PFN
limits so it does not need the backwards compatibility functions to
calculate the zone spanned and absent pages. The removal of the compat_
versions of zone_{abscent,spanned}_pages_in_node() in turn, makes
zone_size and zhole_size parameters unused.
The node_start_pfn is determined by get_pfn_range_for_nid(), so there is
no need to pass it to free_area_init_node().
As a result, the only required parameter to free_area_init_node() is the
node ID, all the rest are removed along with no longer used
compat_zone_{abscent,spanned}_pages_in_node() helpers.
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Hoan Tran <hoan@os.amperecomputing.com> [arm64]
Cc: Baoquan He <bhe@redhat.com>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200412194859.12663-20-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
free_area_init_node() is only used by x86 to initialize a memory-less
nodes. Make its name reflect this and drop all the function parameters
except node ID as they are anyway zero.
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Hoan Tran <hoan@os.amperecomputing.com> [arm64]
Cc: Baoquan He <bhe@redhat.com>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200412194859.12663-19-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some architectures (e.g. ARC) have the ZONE_HIGHMEM zone below the
ZONE_NORMAL. Allowing free_area_init() parse max_zone_pfn array even it
is sorted in descending order allows using free_area_init() on such
architectures.
Add top -> down traversal of max_zone_pfn array in free_area_init() and
use the latter in ARC node/zone initialization.
[rppt@kernel.org: ARC fix]
Link: http://lkml.kernel.org/r/20200504153901.GM14260@kernel.org
[rppt@linux.ibm.com: arc: free_area_init(): take into account PAE40 mode]
Link: http://lkml.kernel.org/r/20200507205900.GH683243@linux.ibm.com
[akpm@linux-foundation.org: declare arch_has_descending_max_zone_pfns()]
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Hoan Tran <hoan@os.amperecomputing.com> [arm64]
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Guenter Roeck <linux@roeck-us.net>
Link: http://lkml.kernel.org/r/20200412194859.12663-18-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The memmap_init() function was made to iterate over memblock regions and
as the result the early_pfn_in_nid() function became obsolete. Since
CONFIG_NODES_SPAN_OTHER_NODES is only used to pick a stub or a real
implementation of early_pfn_in_nid(), it is also not needed anymore.
Remove both early_pfn_in_nid() and the CONFIG_NODES_SPAN_OTHER_NODES.
Co-developed-by: Hoan Tran <Hoan@os.amperecomputing.com>
Signed-off-by: Hoan Tran <Hoan@os.amperecomputing.com>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Hoan Tran <hoan@os.amperecomputing.com> [arm64]
Cc: Baoquan He <bhe@redhat.com>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200412194859.12663-17-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When called during boot the memmap_init_zone() function checks if each PFN
is valid and actually belongs to the node being initialized using
early_pfn_valid() and early_pfn_in_nid().
Each such check may cost up to O(log(n)) where n is the number of memory
banks, so for large amount of memory overall time spent in early_pfn*()
becomes substantial.
Since the information is anyway present in memblock, we can iterate over
memblock memory regions in memmap_init() and only call memmap_init_zone()
for PFN ranges that are know to be valid and in the appropriate node.
[cai@lca.pw: fix a compilation warning from Clang]
Link: http://lkml.kernel.org/r/CF6E407F-17DC-427C-8203-21979FB882EF@lca.pw
[bhe@redhat.com: fix the incorrect hole in fast_isolate_freepages()]
Link: http://lkml.kernel.org/r/8C537EB7-85EE-4DCF-943E-3CC0ED0DF56D@lca.pw
Link: http://lkml.kernel.org/r/20200521014407.29690-1-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Hoan Tran <hoan@os.amperecomputing.com> [arm64]
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Qian Cai <cai@lca.pw>
Link: http://lkml.kernel.org/r/20200412194859.12663-16-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
free_area_init() has effectively became a wrapper for
free_area_init_nodes() and there is no point of keeping it. Still
free_area_init() name is shorter and more general as it does not imply
necessity to initialize multiple nodes.
Rename free_area_init_nodes() to free_area_init(), update the callers and
drop old version of free_area_init().
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Hoan Tran <hoan@os.amperecomputing.com> [arm64]
Reviewed-by: Baoquan He <bhe@redhat.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200412194859.12663-6-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, architectures that use free_area_init() to initialize memory
map and node and zone structures need to calculate zone and hole sizes.
We can use free_area_init_nodes() instead and let it detect the zone
boundaries while the architectures will only have to supply the possible
limits for the zones.
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Hoan Tran <hoan@os.amperecomputing.com> [arm64]
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200412194859.12663-5-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
CONFIG_HAVE_MEMBLOCK_NODE_MAP is used to differentiate initialization of
nodes and zones structures between the systems that have region to node
mapping in memblock and those that don't.
Currently all the NUMA architectures enable this option and for the
non-NUMA systems we can presume that all the memory belongs to node 0 and
therefore the compile time configuration option is not required.
The remaining few architectures that use DISCONTIGMEM without NUMA are
easily updated to use memblock_add_node() instead of memblock_add() and
thus have proper correspondence of memblock regions to NUMA nodes.
Still, free_area_init_node() must have a backward compatible version
because its semantics with and without CONFIG_HAVE_MEMBLOCK_NODE_MAP is
different. Once all the architectures will use the new semantics, the
entire compatibility layer can be dropped.
To avoid addition of extra run time memory to store node id for
architectures that keep memblock but have only a single node, the node id
field of the memblock_region is guarded by CONFIG_NEED_MULTIPLE_NODES and
the corresponding accessors presume that in those cases it is always 0.
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Hoan Tran <hoan@os.amperecomputing.com> [arm64]
Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64]
Cc: Baoquan He <bhe@redhat.com>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200412194859.12663-4-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
early_pfn_to_nid() and its helper __early_pfn_to_nid() are spread around
include/linux/mm.h, include/linux/mmzone.h and mm/page_alloc.c.
Drop unused stub for __early_pfn_to_nid() and move its actual generic
implementation close to its users.
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Hoan Tran <hoan@os.amperecomputing.com> [arm64]
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200412194859.12663-3-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm: rework free_area_init*() funcitons".
After the discussion [1] about removal of CONFIG_NODES_SPAN_OTHER_NODES
and CONFIG_HAVE_MEMBLOCK_NODE_MAP options, I took it a bit further and
updated the node/zone initialization.
Since all architectures have memblock, it is possible to use only the
newer version of free_area_init_node() that calculates the zone and node
boundaries based on memblock node mapping and architectural limits on
possible zone PFNs.
The architectures that still determined zone and hole sizes can be
switched to the generic code and the old code that took those zone and
hole sizes can be simply removed.
And, since it all started from the removal of
CONFIG_NODES_SPAN_OTHER_NODES, the memmap_init() is now updated to iterate
over memblocks and so it does not need to perform early_pfn_to_nid() query
for every PFN.
[1] https://lore.kernel.org/lkml/1585420282-25630-1-git-send-email-Hoan@os.amperecomputing.com
This patch (of 21):
There are several places in the code that directly dereference
memblock_region.nid despite this field being defined only when
CONFIG_HAVE_MEMBLOCK_NODE_MAP=y.
Replace these with calls to memblock_get_region_nid() to improve code
robustness and to avoid possible breakage when
CONFIG_HAVE_MEMBLOCK_NODE_MAP will be removed.
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Hoan Tran <hoan@os.amperecomputing.com> [arm64]
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200412194859.12663-1-rppt@kernel.org
Link: http://lkml.kernel.org/r/20200412194859.12663-2-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull networking updates from David Miller:
1) Allow setting bluetooth L2CAP modes via socket option, from Luiz
Augusto von Dentz.
2) Add GSO partial support to igc, from Sasha Neftin.
3) Several cleanups and improvements to r8169 from Heiner Kallweit.
4) Add IF_OPER_TESTING link state and use it when ethtool triggers a
device self-test. From Andrew Lunn.
5) Start moving away from custom driver versions, use the globally
defined kernel version instead, from Leon Romanovsky.
6) Support GRO vis gro_cells in DSA layer, from Alexander Lobakin.
7) Allow hard IRQ deferral during NAPI, from Eric Dumazet.
8) Add sriov and vf support to hinic, from Luo bin.
9) Support Media Redundancy Protocol (MRP) in the bridging code, from
Horatiu Vultur.
10) Support netmap in the nft_nat code, from Pablo Neira Ayuso.
11) Allow UDPv6 encapsulation of ESP in the ipsec code, from Sabrina
Dubroca. Also add ipv6 support for espintcp.
12) Lots of ReST conversions of the networking documentation, from Mauro
Carvalho Chehab.
13) Support configuration of ethtool rxnfc flows in bcmgenet driver,
from Doug Berger.
14) Allow to dump cgroup id and filter by it in inet_diag code, from
Dmitry Yakunin.
15) Add infrastructure to export netlink attribute policies to
userspace, from Johannes Berg.
16) Several optimizations to sch_fq scheduler, from Eric Dumazet.
17) Fallback to the default qdisc if qdisc init fails because otherwise
a packet scheduler init failure will make a device inoperative. From
Jesper Dangaard Brouer.
18) Several RISCV bpf jit optimizations, from Luke Nelson.
19) Correct the return type of the ->ndo_start_xmit() method in several
drivers, it's netdev_tx_t but many drivers were using
'int'. From Yunjian Wang.
20) Add an ethtool interface for PHY master/slave config, from Oleksij
Rempel.
21) Add BPF iterators, from Yonghang Song.
22) Add cable test infrastructure, including ethool interfaces, from
Andrew Lunn. Marvell PHY driver is the first to support this
facility.
23) Remove zero-length arrays all over, from Gustavo A. R. Silva.
24) Calculate and maintain an explicit frame size in XDP, from Jesper
Dangaard Brouer.
25) Add CAP_BPF, from Alexei Starovoitov.
26) Support terse dumps in the packet scheduler, from Vlad Buslov.
27) Support XDP_TX bulking in dpaa2 driver, from Ioana Ciornei.
28) Add devm_register_netdev(), from Bartosz Golaszewski.
29) Minimize qdisc resets, from Cong Wang.
30) Get rid of kernel_getsockopt and kernel_setsockopt in order to
eliminate set_fs/get_fs calls. From Christoph Hellwig.
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2517 commits)
selftests: net: ip_defrag: ignore EPERM
net_failover: fixed rollback in net_failover_open()
Revert "tipc: Fix potential tipc_aead refcnt leak in tipc_crypto_rcv"
Revert "tipc: Fix potential tipc_node refcnt leak in tipc_rcv"
vmxnet3: allow rx flow hash ops only when rss is enabled
hinic: add set_channels ethtool_ops support
selftests/bpf: Add a default $(CXX) value
tools/bpf: Don't use $(COMPILE.c)
bpf, selftests: Use bpf_probe_read_kernel
s390/bpf: Use bcr 0,%0 as tail call nop filler
s390/bpf: Maintain 8-byte stack alignment
selftests/bpf: Fix verifier test
selftests/bpf: Fix sample_cnt shared between two threads
bpf, selftests: Adapt cls_redirect to call csum_level helper
bpf: Add csum_level helper for fixing up csum levels
bpf: Fix up bpf_skb_adjust_room helper's skb csum setting
sfc: add missing annotation for efx_ef10_try_update_nic_stats_vf()
crypto/chtls: IPv6 support for inline TLS
Crypto/chcr: Fixes a coccinile check error
Crypto/chcr: Fixes compilations warnings
...
Merge updates from Andrew Morton:
"A few little subsystems and a start of a lot of MM patches.
Subsystems affected by this patch series: squashfs, ocfs2, parisc,
vfs. With mm subsystems: slab-generic, slub, debug, pagecache, gup,
swap, memcg, pagemap, memory-failure, vmalloc, kasan"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (128 commits)
kasan: move kasan_report() into report.c
mm/mm_init.c: report kasan-tag information stored in page->flags
ubsan: entirely disable alignment checks under UBSAN_TRAP
kasan: fix clang compilation warning due to stack protector
x86/mm: remove vmalloc faulting
mm: remove vmalloc_sync_(un)mappings()
x86/mm/32: implement arch_sync_kernel_mappings()
x86/mm/64: implement arch_sync_kernel_mappings()
mm/ioremap: track which page-table levels were modified
mm/vmalloc: track which page-table levels were modified
mm: add functions to track page directory modifications
s390: use __vmalloc_node in stack_alloc
powerpc: use __vmalloc_node in alloc_vm_stack
arm64: use __vmalloc_node in arch_alloc_vmap_stack
mm: remove vmalloc_user_node_flags
mm: switch the test_vmalloc module to use __vmalloc_node
mm: remove __vmalloc_node_flags_caller
mm: remove both instances of __vmalloc_node_flags
mm: remove the prot argument to __vmalloc_node
mm: remove the pgprot argument to __vmalloc
...
After an NFS page has been written it is considered "unstable" until a
COMMIT request succeeds. If the COMMIT fails, the page will be
re-written.
These "unstable" pages are currently accounted as "reclaimable", either
in WB_RECLAIMABLE, or in NR_UNSTABLE_NFS which is included in a
'reclaimable' count. This might have made sense when sending the COMMIT
required a separate action by the VFS/MM (e.g. releasepage() used to
send a COMMIT). However now that all writes generated by ->writepages()
will automatically be followed by a COMMIT (since commit 919e3bd9a8
("NFS: Ensure we commit after writeback is complete")) it makes more
sense to treat them as writeback pages.
So this patch removes NR_UNSTABLE_NFS and accounts unstable pages in
NR_WRITEBACK and WB_WRITEBACK.
A particular effect of this change is that when
wb_check_background_flush() calls wb_over_bg_threshold(), the latter
will report 'true' a lot less often as the 'unstable' pages are no
longer considered 'dirty' (as there is nothing that writeback can do
about them anyway).
Currently wb_check_background_flush() will trigger writeback to NFS even
when there are relatively few dirty pages (if there are lots of unstable
pages), this can result in small writes going to the server (10s of
Kilobytes rather than a Megabyte) which hurts throughput. With this
patch, there are fewer writes which are each larger on average.
Where the NR_UNSTABLE_NFS count was included in statistics
virtual-files, the entry is retained, but the value is hard-coded as
zero. static trace points and warning printks which mentioned this
counter no longer report it.
[akpm@linux-foundation.org: re-layout comment]
[akpm@linux-foundation.org: fix printk warning]
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Acked-by: Michal Hocko <mhocko@suse.com> [mm]
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Link: http://lkml.kernel.org/r/87d06j7gqa.fsf@notabene.neil.brown.name
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Branch Target Identification (BTI)
* Support for ARMv8.5-BTI in both user- and kernel-space. This
allows branch targets to limit the types of branch from which
they can be called and additionally prevents branching to
arbitrary code, although kernel support requires a very recent
toolchain.
* Function annotation via SYM_FUNC_START() so that assembly
functions are wrapped with the relevant "landing pad"
instructions.
* BPF and vDSO updates to use the new instructions.
* Addition of a new HWCAP and exposure of BTI capability to
userspace via ID register emulation, along with ELF loader
support for the BTI feature in .note.gnu.property.
* Non-critical fixes to CFI unwind annotations in the sigreturn
trampoline.
- Shadow Call Stack (SCS)
* Support for Clang's Shadow Call Stack feature, which reserves
platform register x18 to point at a separate stack for each
task that holds only return addresses. This protects function
return control flow from buffer overruns on the main stack.
* Save/restore of x18 across problematic boundaries (user-mode,
hypervisor, EFI, suspend, etc).
* Core support for SCS, should other architectures want to use it
too.
* SCS overflow checking on context-switch as part of the existing
stack limit check if CONFIG_SCHED_STACK_END_CHECK=y.
- CPU feature detection
* Removed numerous "SANITY CHECK" errors when running on a system
with mismatched AArch32 support at EL1. This is primarily a
concern for KVM, which disabled support for 32-bit guests on
such a system.
* Addition of new ID registers and fields as the architecture has
been extended.
- Perf and PMU drivers
* Minor fixes and cleanups to system PMU drivers.
- Hardware errata
* Unify KVM workarounds for VHE and nVHE configurations.
* Sort vendor errata entries in Kconfig.
- Secure Monitor Call Calling Convention (SMCCC)
* Update to the latest specification from Arm (v1.2).
* Allow PSCI code to query the SMCCC version.
- Software Delegated Exception Interface (SDEI)
* Unexport a bunch of unused symbols.
* Minor fixes to handling of firmware data.
- Pointer authentication
* Add support for dumping the kernel PAC mask in vmcoreinfo so
that the stack can be unwound by tools such as kdump.
* Simplification of key initialisation during CPU bringup.
- BPF backend
* Improve immediate generation for logical and add/sub
instructions.
- vDSO
- Minor fixes to the linker flags for consistency with other
architectures and support for LLVM's unwinder.
- Clean up logic to initialise and map the vDSO into userspace.
- ACPI
- Work around for an ambiguity in the IORT specification relating
to the "num_ids" field.
- Support _DMA method for all named components rather than only
PCIe root complexes.
- Minor other IORT-related fixes.
- Miscellaneous
* Initialise debug traps early for KGDB and fix KDB cacheflushing
deadlock.
* Minor tweaks to early boot state (documentation update, set
TEXT_OFFSET to 0x0, increase alignment of PE/COFF sections).
* Refactoring and cleanup
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Will Deacon:
"A sizeable pile of arm64 updates for 5.8.
Summary below, but the big two features are support for Branch Target
Identification and Clang's Shadow Call stack. The latter is currently
arm64-only, but the high-level parts are all in core code so it could
easily be adopted by other architectures pending toolchain support
Branch Target Identification (BTI):
- Support for ARMv8.5-BTI in both user- and kernel-space. This allows
branch targets to limit the types of branch from which they can be
called and additionally prevents branching to arbitrary code,
although kernel support requires a very recent toolchain.
- Function annotation via SYM_FUNC_START() so that assembly functions
are wrapped with the relevant "landing pad" instructions.
- BPF and vDSO updates to use the new instructions.
- Addition of a new HWCAP and exposure of BTI capability to userspace
via ID register emulation, along with ELF loader support for the
BTI feature in .note.gnu.property.
- Non-critical fixes to CFI unwind annotations in the sigreturn
trampoline.
Shadow Call Stack (SCS):
- Support for Clang's Shadow Call Stack feature, which reserves
platform register x18 to point at a separate stack for each task
that holds only return addresses. This protects function return
control flow from buffer overruns on the main stack.
- Save/restore of x18 across problematic boundaries (user-mode,
hypervisor, EFI, suspend, etc).
- Core support for SCS, should other architectures want to use it
too.
- SCS overflow checking on context-switch as part of the existing
stack limit check if CONFIG_SCHED_STACK_END_CHECK=y.
CPU feature detection:
- Removed numerous "SANITY CHECK" errors when running on a system
with mismatched AArch32 support at EL1. This is primarily a concern
for KVM, which disabled support for 32-bit guests on such a system.
- Addition of new ID registers and fields as the architecture has
been extended.
Perf and PMU drivers:
- Minor fixes and cleanups to system PMU drivers.
Hardware errata:
- Unify KVM workarounds for VHE and nVHE configurations.
- Sort vendor errata entries in Kconfig.
Secure Monitor Call Calling Convention (SMCCC):
- Update to the latest specification from Arm (v1.2).
- Allow PSCI code to query the SMCCC version.
Software Delegated Exception Interface (SDEI):
- Unexport a bunch of unused symbols.
- Minor fixes to handling of firmware data.
Pointer authentication:
- Add support for dumping the kernel PAC mask in vmcoreinfo so that
the stack can be unwound by tools such as kdump.
- Simplification of key initialisation during CPU bringup.
BPF backend:
- Improve immediate generation for logical and add/sub instructions.
vDSO:
- Minor fixes to the linker flags for consistency with other
architectures and support for LLVM's unwinder.
- Clean up logic to initialise and map the vDSO into userspace.
ACPI:
- Work around for an ambiguity in the IORT specification relating to
the "num_ids" field.
- Support _DMA method for all named components rather than only PCIe
root complexes.
- Minor other IORT-related fixes.
Miscellaneous:
- Initialise debug traps early for KGDB and fix KDB cacheflushing
deadlock.
- Minor tweaks to early boot state (documentation update, set
TEXT_OFFSET to 0x0, increase alignment of PE/COFF sections).
- Refactoring and cleanup"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (148 commits)
KVM: arm64: Move __load_guest_stage2 to kvm_mmu.h
KVM: arm64: Check advertised Stage-2 page size capability
arm64/cpufeature: Add get_arm64_ftr_reg_nowarn()
ACPI/IORT: Remove the unused __get_pci_rid()
arm64/cpuinfo: Add ID_MMFR4_EL1 into the cpuinfo_arm64 context
arm64/cpufeature: Add remaining feature bits in ID_AA64PFR1 register
arm64/cpufeature: Add remaining feature bits in ID_AA64PFR0 register
arm64/cpufeature: Add remaining feature bits in ID_AA64ISAR0 register
arm64/cpufeature: Add remaining feature bits in ID_MMFR4 register
arm64/cpufeature: Add remaining feature bits in ID_PFR0 register
arm64/cpufeature: Introduce ID_MMFR5 CPU register
arm64/cpufeature: Introduce ID_DFR1 CPU register
arm64/cpufeature: Introduce ID_PFR2 CPU register
arm64/cpufeature: Make doublelock a signed feature in ID_AA64DFR0
arm64/cpufeature: Drop TraceFilt feature exposure from ID_DFR0 register
arm64/cpufeature: Add explicit ftr_id_isar0[] for ID_ISAR0 register
arm64: mm: Add asid_gen_match() helper
firmware: smccc: Fix missing prototype warning for arm_smccc_version_init
arm64: vdso: Fix CFI directives in sigreturn trampoline
arm64: vdso: Don't prefix sigreturn trampoline with a BTI C instruction
...
Move the bpf verifier trace check into the new switch statement in
HEAD.
Resolve the overlapping changes in hinic, where bug fixes overlap
the addition of VF support.
Signed-off-by: David S. Miller <davem@davemloft.net>
This change adds accounting for the memory allocated for shadow stacks.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Commit 1c30844d2d ("mm: reclaim small amounts of memory when an
external fragmentation event occurs") adds a boost_watermark() function
which increases the min watermark in a zone by at least
pageblock_nr_pages or the number of pages in a page block.
On Arm64, with 64K pages and 512M huge pages, this is 8192 pages or
512M. It does this regardless of the number of managed pages managed in
the zone or the likelihood of success.
This can put the zone immediately under water in terms of allocating
pages from the zone, and can cause a small machine to fail immediately
due to OoM. Unlike set_recommended_min_free_kbytes(), which
substantially increases min_free_kbytes and is tied to THP,
boost_watermark() can be called even if THP is not active.
The problem is most likely to appear on architectures such as Arm64
where pageblock_nr_pages is very large.
It is desirable to run the kdump capture kernel in as small a space as
possible to avoid wasting memory. In some architectures, such as Arm64,
there are restrictions on where the capture kernel can run, and
therefore, the space available. A capture kernel running in 768M can
fail due to OoM immediately after boost_watermark() sets the min in zone
DMA32, where most of the memory is, to 512M. It fails even though there
is over 500M of free memory. With boost_watermark() suppressed, the
capture kernel can run successfully in 448M.
This patch limits boost_watermark() to boosting a zone's min watermark
only when there are enough pages that the boost will produce positive
results. In this case that is estimated to be four times as many pages
as pageblock_nr_pages.
Mel said:
: There is no harm in marking it stable. Clearly it does not happen very
: often but it's not impossible. 32-bit x86 is a lot less common now
: which would previously have been vulnerable to triggering this easily.
: ppc64 has a larger base page size but typically only has one zone.
: arm64 is likely the most vulnerable, particularly when CMA is
: configured with a small movable zone.
Fixes: 1c30844d2d ("mm: reclaim small amounts of memory when an external fragmentation event occurs")
Signed-off-by: Henry Willard <henry.willard@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/1588294148-6586-1-git-send-email-henry.willard@oracle.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Without CONFIG_PREEMPT, it can happen that we get soft lockups detected,
e.g., while booting up.
watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [swapper/0:1]
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.6.0-next-20200331+ #4
Hardware name: Red Hat KVM, BIOS 1.11.1-4.module+el8.1.0+4066+0f1aadab 04/01/2014
RIP: __pageblock_pfn_to_page+0x134/0x1c0
Call Trace:
set_zone_contiguous+0x56/0x70
page_alloc_init_late+0x166/0x176
kernel_init_freeable+0xfa/0x255
kernel_init+0xa/0x106
ret_from_fork+0x35/0x40
The issue becomes visible when having a lot of memory (e.g., 4TB)
assigned to a single NUMA node - a system that can easily be created
using QEMU. Inside VMs on a hypervisor with quite some memory
overcommit, this is fairly easy to trigger.
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Shile Zhang <shile.zhang@linux.alibaba.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Shile Zhang <shile.zhang@linux.alibaba.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200416073417.5003-1-david@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Instead of having all the sysctl handlers deal with user pointers, which
is rather hairy in terms of the BPF interaction, copy the input to and
from userspace in common code. This also means that the strings are
always NUL-terminated by the common code, making the API a little bit
safer.
As most handler just pass through the data to one of the common handlers
a lot of the changes are mechnical.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
watermark_boost_factor_sysctl_handler is just a pointless wrapper for
proc_dointvec_minmax, so remove it and use proc_dointvec_minmax
directly.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Fix the following sparse warning:
mm/page_alloc.c:106:1: warning: symbol 'pcpu_drain_mutex' was not declared. Should it be static?
mm/page_alloc.c:107:1: warning: symbol '__pcpu_scope_pcpu_drain' was not declared. Should it be static?
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200407023925.46438-1-yanaijie@huawei.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add description of function parameter 'mt' to fix kernel-doc warning:
mm/page_alloc.c:3246: warning: Function parameter or member 'mt' not described in '__putback_isolated_page'
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Link: http://lkml.kernel.org/r/02998bd4-0b82-2f15-2570-f86130304d1e@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In order to pave the way for free page reporting in virtualized
environments we will need a way to get pages out of the free lists and
identify those pages after they have been returned. To accomplish this,
this patch adds the concept of a Reported Buddy, which is essentially
meant to just be the Uptodate flag used in conjunction with the Buddy page
type.
To prevent the reported pages from leaking outside of the buddy lists I
added a check to clear the PageReported bit in the del_page_from_free_list
function. As a result any reported page that is split, merged, or
allocated will have the flag cleared prior to the PageBuddy value being
cleared.
The process for reporting pages is fairly simple. Once we free a page
that meets the minimum order for page reporting we will schedule a worker
thread to start 2s or more in the future. That worker thread will begin
working from the lowest supported page reporting order up to MAX_ORDER - 1
pulling unreported pages from the free list and storing them in the
scatterlist.
When processing each individual free list it is necessary for the worker
thread to release the zone lock when it needs to stop and report the full
scatterlist of pages. To reduce the work of the next iteration the worker
thread will rotate the free list so that the first unreported page in the
free list becomes the first entry in the list.
It will then call a reporting function providing information on how many
entries are in the scatterlist. Once the function completes it will
return the pages to the free area from which they were allocated and start
over pulling more pages from the free areas until there are no longer
enough pages to report on to keep the worker busy, or we have processed as
many pages as were contained in the free area when we started processing
the list.
The worker thread will work in a round-robin fashion making its way though
each zone requesting reporting, and through each reportable free list
within that zone. Once all free areas within the zone have been processed
it will check to see if there have been any requests for reporting while
it was processing. If so it will reschedule the worker thread to start up
again in roughly 2s and exit.
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Nitesh Narayan Lal <nitesh@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pankaj Gupta <pagupta@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Wang <wei.w.wang@intel.com>
Cc: Yang Zhang <yang.zhang.wz@gmail.com>
Cc: wei qi <weiqi4@huawei.com>
Link: http://lkml.kernel.org/r/20200211224635.29318.19750.stgit@localhost.localdomain
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are cases where we would benefit from avoiding having to go through
the allocation and free cycle to return an isolated page.
Examples for this might include page poisoning in which we isolate a page
and then put it back in the free list without ever having actually
allocated it.
This will enable us to also avoid notifiers for the future free page
reporting which will need to avoid retriggering page reporting when
returning pages that have been reported on.
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Nitesh Narayan Lal <nitesh@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pankaj Gupta <pagupta@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Wang <wei.w.wang@intel.com>
Cc: Yang Zhang <yang.zhang.wz@gmail.com>
Cc: wei qi <weiqi4@huawei.com>
Link: http://lkml.kernel.org/r/20200211224624.29318.89287.stgit@localhost.localdomain
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In order to enable the use of the zone from the list manipulator functions
I will need access to the zone pointer. As it turns out most of the
accessors were always just being directly passed &zone->free_area[order]
anyway so it would make sense to just fold that into the function itself
and pass the zone and order as arguments instead of the free area.
In order to be able to reference the zone we need to move the declaration
of the functions down so that we have the zone defined before we define
the list manipulation functions. Since the functions are only used in the
file mm/page_alloc.c we can just move them there to reduce noise in the
header.
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Pankaj Gupta <pagupta@redhat.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Nitesh Narayan Lal <nitesh@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Wang <wei.w.wang@intel.com>
Cc: Yang Zhang <yang.zhang.wz@gmail.com>
Cc: wei qi <weiqi4@huawei.com>
Link: http://lkml.kernel.org/r/20200211224613.29318.43080.stgit@localhost.localdomain
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm / virtio: Provide support for free page reporting", v17.
This series provides an asynchronous means of reporting free guest pages
to a hypervisor so that the memory associated with those pages can be
dropped and reused by other processes and/or guests on the host. Using
this it is possible to avoid unnecessary I/O to disk and greatly improve
performance in the case of memory overcommit on the host.
When enabled we will be performing a scan of free memory every 2 seconds
while pages of sufficiently high order are being freed. In each pass at
least one sixteenth of each free list will be reported. By doing this we
avoid racing against other threads that may be causing a high amount of
memory churn.
The lowest page order currently scanned when reporting pages is
pageblock_order so that this feature will not interfere with the use of
Transparent Huge Pages in the case of virtualization.
Currently this is only in use by virtio-balloon however there is the hope
that at some point in the future other hypervisors might be able to make
use of it. In the virtio-balloon/QEMU implementation the hypervisor is
currently using MADV_DONTNEED to indicate to the host kernel that the page
is currently free. It will be zeroed and faulted back into the guest the
next time the page is accessed.
To track if a page is reported or not the Uptodate flag was repurposed and
used as a Reported flag for Buddy pages. We walk though the free list
isolating pages and adding them to the scatterlist until we either
encounter the end of the list or have processed at least one sixteenth of
the pages that were listed in nr_free prior to us starting. If we fill
the scatterlist before we reach the end of the list we rotate the list so
that the first unreported page we encounter is moved to the head of the
list as that is where we will resume after we have freed the reported
pages back into the tail of the list.
Below are the results from various benchmarks. I primarily focused on two
tests. The first is the will-it-scale/page_fault2 test, and the other is
a modified version of will-it-scale/page_fault1 that was enabled to use
THP. I did this as it allows for better visibility into different parts
of the memory subsystem. The guest is running with 32G for RAM on one
node of a E5-2630 v3. The host has had some features such as CPU turbo
disabled in the BIOS.
Test page_fault1 (THP) page_fault2
Name tasks Process Iter STDEV Process Iter STDEV
Baseline 1 1012402.50 0.14% 361855.25 0.81%
16 8827457.25 0.09% 3282347.00 0.34%
Patches Applied 1 1007897.00 0.23% 361887.00 0.26%
16 8784741.75 0.39% 3240669.25 0.48%
Patches Enabled 1 1010227.50 0.39% 359749.25 0.56%
16 8756219.00 0.24% 3226608.75 0.97%
Patches Enabled 1 1050982.00 4.26% 357966.25 0.14%
page shuffle 16 8672601.25 0.49% 3223177.75 0.40%
Patches enabled 1 1003238.00 0.22% 360211.00 0.22%
shuffle w/ RFC 16 8767010.50 0.32% 3199874.00 0.71%
The results above are for a baseline with a linux-next-20191219 kernel,
that kernel with this patch set applied but page reporting disabled in
virtio-balloon, the patches applied and page reporting fully enabled, the
patches enabled with page shuffling enabled, and the patches applied with
page shuffling enabled and an RFC patch that makes used of MADV_FREE in
QEMU. These results include the deviation seen between the average value
reported here versus the high and/or low value. I observed that during
the test memory usage for the first three tests never dropped whereas with
the patches fully enabled the VM would drop to using only a few GB of the
host's memory when switching from memhog to page fault tests.
Any of the overhead visible with this patch set enabled seems due to page
faults caused by accessing the reported pages and the host zeroing the
page before giving it back to the guest. This overhead is much more
visible when using THP than with standard 4K pages. In addition page
shuffling seemed to increase the amount of faults generated due to an
increase in memory churn. The overehad is reduced when using MADV_FREE as
we can avoid the extra zeroing of the pages when they are reintroduced to
the host, as can be seen when the RFC is applied with shuffling enabled.
The overall guest size is kept fairly small to only a few GB while the
test is running. If the host memory were oversubscribed this patch set
should result in a performance improvement as swapping memory in the host
can be avoided.
A brief history on the background of free page reporting can be found at:
https://lore.kernel.org/lkml/29f43d5796feed0dec8e8bb98b187d9dac03b900.camel@linux.intel.com/
This patch (of 9):
Move the head/tail adding logic out of the shuffle code and into the
__free_one_page function since ultimately that is where it is really
needed anyway. By doing this we should be able to reduce the overhead and
can consolidate all of the list addition bits in one spot.
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Yang Zhang <yang.zhang.wz@gmail.com>
Cc: Pankaj Gupta <pagupta@redhat.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Nitesh Narayan Lal <nitesh@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Wei Wang <wei.w.wang@intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: wei qi <weiqi4@huawei.com>
Link: http://lkml.kernel.org/r/20200211224602.29318.84523.stgit@localhost.localdomain
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The code to implement THP migrations already exists, and the code for CMA
to clear out a region of memory already exists.
Only a few small tweaks are needed to allow CMA to move THP memory when
attempting an allocation from alloc_contig_range.
With these changes, migrating THPs from a CMA area works when allocating a
1GB hugepage from CMA memory.
[riel@surriel.com: fix hugetlbfs pages per Mike, cleanup per Vlastimil]
Link: http://lkml.kernel.org/r/20200228104700.0af2f18d@imladris.surriel.com
Signed-off-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: David Rientjes <rientjes@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Link: http://lkml.kernel.org/r/20200227213238.1298752-2-riel@surriel.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "fix THP migration for CMA allocations", v2.
Transparent huge pages are allocated with __GFP_MOVABLE, and can end up in
CMA memory blocks. Transparent huge pages also have most of the
infrastructure in place to allow migration.
However, a few pieces were missing, causing THP migration to fail when
attempting to use CMA to allocate 1GB hugepages.
With these patches in place, THP migration from CMA blocks seems to work,
both for anonymous THPs and for tmpfs/shmem THPs.
This patch (of 2):
Add information to struct compact_control to indicate that the allocator
would really like to clear out this specific part of memory, used by for
example CMA.
Signed-off-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Link: http://lkml.kernel.org/r/20200227213238.1298752-1-riel@surriel.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Previously if branch condition was false, the assignment was not executed.
The assignment can be safely executed even when the condition is false
and it is not incorrect as it assigns the value of 'nodemask' to
'ac.nodemask' which already has the same value.
So as the assignment can be executed unconditionally, the branch can be
removed.
Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: http://lkml.kernel.org/r/20200307225335.31300-1-mateusznosek0@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use free_area_empty() API to replace list_empty() for better code
readability.
Signed-off-by: chenqiwu <chenqiwu@xiaomi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: http://lkml.kernel.org/r/1583674354-7713-1-git-send-email-qiwuchen55@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch makes ALLOC_KSWAPD equal to __GFP_KSWAPD_RECLAIM (cast to int).
Thanks to that code like:
if (gfp_mask & __GFP_KSWAPD_RECLAIM)
alloc_flags |= ALLOC_KSWAPD;
can be changed to:
alloc_flags |= (__force int) (gfp_mask &__GFP_KSWAPD_RECLAIM);
Thanks to this one branch less is generated in the assembly.
In case of ALLOC_KSWAPD flag two branches are saved, first one in code
that always executes in the beginning of page allocation and the second
one in loop in page allocator slowpath.
Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Link: http://lkml.kernel.org/r/20200304162118.14784-1-mateusznosek0@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, the vm.min_free_kbytes sysctl value is capped at a hardcoded
64M in init_per_zone_wmark_min (unless it is overridden by khugepaged
initialization).
This value has not been modified since 2005, and enterprise-grade systems
now frequently have hundreds of GB of RAM and multiple 10, 40, or even 100
GB NICs. We have seen page allocation failures on heavily loaded systems
related to NIC drivers. These issues were resolved by an increase to
vm.min_free_kbytes.
This patch increases the hardcoded value by a factor of 4 as a temporary
solution.
Further work to make the calculation of vm.min_free_kbytes more consistent
throughout the kernel would be desirable.
As an example of the inconsistency of the current method, this value is
recalculated by init_per_zone_wmark_min() in the case of memory hotplug
which will override the value set by set_recommended_min_free_kbytes()
called during khugepaged initialization even if khugepaged remains
enabled, however an on/off toggle of khugepaged will then recalculate and
set the value via set_recommended_min_free_kbytes().
Signed-off-by: Joel Savitz <jsavitz@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Rafael Aquini <aquini@redhat.com>
Link: http://lkml.kernel.org/r/20200220150103.5183-1-jsavitz@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rename (__)memcg_kmem_(un)charge() into (__)memcg_kmem_(un)charge_page()
to better reflect what they are actually doing:
1) call __memcg_kmem_(un)charge_memcg() to actually charge or uncharge
the current memcg
2) set or clear the PageKmemcg flag
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Link: http://lkml.kernel.org/r/20200109202659.752357-4-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For huge pages (and in fact, any compound page), the GUP_PIN_COUNTING_BIAS
scheme tends to overflow too easily, each tail page increments the head
page->_refcount by GUP_PIN_COUNTING_BIAS (1024). That limits the number
of huge pages that can be pinned.
This patch removes that limitation, by using an exact form of pin counting
for compound pages of order > 1. The "order > 1" is required because this
approach uses the 3rd struct page in the compound page, and order 1
compound pages only have two pages, so that won't work there.
A new struct page field, hpage_pinned_refcount, has been added, replacing
a padding field in the union (so no new space is used).
This enhancement also has a useful side effect: huge pages and compound
pages (of order > 1) do not suffer from the "potential false positives"
problem that is discussed in the page_dma_pinned() comment block. That is
because these compound pages have extra space for tracking things, so they
get exact pin counts instead of overloading page->_refcount.
Documentation/core-api/pin_user_pages.rst is updated accordingly.
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Link: http://lkml.kernel.org/r/20200211001536.1027652-8-jhubbard@nvidia.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit ad2c814441.
The function node_to_mem_node() was introduced by that commit for use in SLUB
on systems with memoryless nodes, but it turned out to be unreliable on some
architectures/configurations and a simpler solution exists than fixing it up.
Thus commit 0715e6c516 ("mm, slub: prevent kmalloc_node crashes and
memory leaks") removed the only user of node_to_mem_node() and we can
revert the commit that introduced the function.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Bharata B Rao <bharata@linux.ibm.com>
Cc: Christopher Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Nathan Lynch <nathanl@linux.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: PUVICHAKRAVARTHY RAMACHANDRAN <puvichakravarthy@in.ibm.com>
Cc: Sachin Sant <sachinp@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20200320115533.9604-2-vbabka@suse.cz
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm/memory_hotplug: Shrink zones before removing memory", v6.
This series fixes the access of uninitialized memmaps when shrinking
zones/nodes and when removing memory. Also, it contains all fixes for
crashes that can be triggered when removing certain namespace using
memunmap_pages() - ZONE_DEVICE, reported by Aneesh.
We stop trying to shrink ZONE_DEVICE, as it's buggy, fixing it would be
more involved (we don't have SECTION_IS_ONLINE as an indicator), and
shrinking is only of limited use (set_zone_contiguous() cannot detect the
ZONE_DEVICE as contiguous).
We continue shrinking !ZONE_DEVICE zones, however, I reduced the amount of
code to a minimum. Shrinking is especially necessary to keep
zone->contiguous set where possible, especially, on memory unplug of DIMMs
at zone boundaries.
--------------------------------------------------------------------------
Zones are now properly shrunk when offlining memory blocks or when
onlining failed. This allows to properly shrink zones on memory unplug
even if the separate memory blocks of a DIMM were onlined to different
zones or re-onlined to a different zone after offlining.
Example:
:/# cat /proc/zoneinfo
Node 1, zone Movable
spanned 0
present 0
managed 0
:/# echo "online_movable" > /sys/devices/system/memory/memory41/state
:/# echo "online_movable" > /sys/devices/system/memory/memory43/state
:/# cat /proc/zoneinfo
Node 1, zone Movable
spanned 98304
present 65536
managed 65536
:/# echo 0 > /sys/devices/system/memory/memory43/online
:/# cat /proc/zoneinfo
Node 1, zone Movable
spanned 32768
present 32768
managed 32768
:/# echo 0 > /sys/devices/system/memory/memory41/online
:/# cat /proc/zoneinfo
Node 1, zone Movable
spanned 0
present 0
managed 0
This patch (of 6):
The third argument is actually number of pages. Change the variable name
from size to nr_pages to indicate this better.
No functional change in this patch.
Link: http://lkml.kernel.org/r/20191006085646.5768-3-david@redhat.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Pankaj Gupta <pagupta@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Let's move it to the header and use the shorter variant from
mm/page_alloc.c (the original one will also check
"__highest_present_section_nr + 1", which is not necessary). While at
it, make the section_nr in next_pfn() const.
In next_pfn(), we now return section_nr_to_pfn(-1) instead of -1 once we
exceed __highest_present_section_nr, which doesn't make a difference in
the caller as it is big enough (>= all sane end_pfn).
Link: http://lkml.kernel.org/r/20200113144035.10848-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: "Jin, Zhi" <zhi.jin@intel.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Let's update the pfn manually whenever we continue the loop. This makes
the code easier to read but also less error prone (and we can directly fix
one issue).
When overlap_memmap_init() returns true, pfn is updated to
"memblock_region_memory_end_pfn(r)". So it already points at the *next*
pfn to process. Incrementing the pfn another time is wrong, we might
leave one uninitialized. I spotted this by inspecting the code, so I have
no idea if this is relevant in practise (with kernelcore=mirror).
Link: http://lkml.kernel.org/r/20200113144035.10848-2-david@redhat.com
Fixes: a9a9e77fbf ("mm: move mirrored memory specific code outside of memmap_init_zone")
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Baoquan He <bhe@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: "Jin, Zhi" <zhi.jin@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Let's make sure that all memory holes are actually marked PageReserved(),
that page_to_pfn() produces reliable results, and that these pages are not
detected as "mmap" pages due to the mapcount.
E.g., booting a x86-64 QEMU guest with 4160 MB:
[ 0.010585] Early memory node ranges
[ 0.010586] node 0: [mem 0x0000000000001000-0x000000000009efff]
[ 0.010588] node 0: [mem 0x0000000000100000-0x00000000bffdefff]
[ 0.010589] node 0: [mem 0x0000000100000000-0x0000000143ffffff]
max_pfn is 0x144000.
Before this change:
[root@localhost ~]# ./page-types -r -a 0x144000,
flags page-count MB symbolic-flags long-symbolic-flags
0x0000000000000800 16384 64 ___________M_______________________________ mmap
total 16384 64
After this change:
[root@localhost ~]# ./page-types -r -a 0x144000,
flags page-count MB symbolic-flags long-symbolic-flags
0x0000000100000000 16384 64 ___________________________r_______________ reserved
total 16384 64
IOW, especially the unavailable physical memory ("memory hole") in the
last section would not get properly marked PageReserved() and is indicated
to be "mmap" memory.
Drop the trace of that function from include/linux/mm.h - nobody else
needs it, and rename it accordingly.
Note: The fake zone/node might not be covered by the zone/node span. This
is not an urgent issue (for now, we had the same node/zone due to the
zeroing). We'll need a clean way to mark memory holes (e.g., using a page
type PageHole() if possible or a fake ZONE_INVALID) and eventually stop
marking these memory holes PageReserved().
Link: http://lkml.kernel.org/r/20191211163201.17179-4-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Bob Picco <bob.picco@oracle.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Sistare <steven.sistare@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm: fix max_pfn not falling on section boundary", v2.
Playing with different memory sizes for a x86-64 guest, I discovered that
some memmaps (highest section if max_mem does not fall on the section
boundary) are marked as being valid and online, but contain garbage. We
have to properly initialize these memmaps.
Looking at /proc/kpageflags and friends, I found some more issues,
partially related to this.
This patch (of 3):
If max_pfn is not aligned to a section boundary, we can easily run into
BUGs. This can e.g., be triggered on x86-64 under QEMU by specifying a
memory size that is not a multiple of 128MB (e.g., 4097MB, but also
4160MB). I was told that on real HW, we can easily have this scenario
(esp., one of the main reasons sub-section hotadd of devmem was added).
The issue is, that we have a valid memmap (pfn_valid()) for the whole
section, and the whole section will be marked "online".
pfn_to_online_page() will succeed, but the memmap contains garbage.
E.g., doing a "./page-types -r -a 0x144001" when QEMU was started with "-m
4160M" - (see tools/vm/page-types.c):
[ 200.476376] BUG: unable to handle page fault for address: fffffffffffffffe
[ 200.477500] #PF: supervisor read access in kernel mode
[ 200.478334] #PF: error_code(0x0000) - not-present page
[ 200.479076] PGD 59614067 P4D 59614067 PUD 59616067 PMD 0
[ 200.479557] Oops: 0000 [#4] SMP NOPTI
[ 200.479875] CPU: 0 PID: 603 Comm: page-types Tainted: G D W 5.5.0-rc1-next-20191209 #93
[ 200.480646] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu4
[ 200.481648] RIP: 0010:stable_page_flags+0x4d/0x410
[ 200.482061] Code: f3 ff 41 89 c0 48 b8 00 00 00 00 01 00 00 00 45 84 c0 0f 85 cd 02 00 00 48 8b 53 08 48 8b 2b 48f
[ 200.483644] RSP: 0018:ffffb139401cbe60 EFLAGS: 00010202
[ 200.484091] RAX: fffffffffffffffe RBX: fffffbeec5100040 RCX: 0000000000000000
[ 200.484697] RDX: 0000000000000001 RSI: ffffffff9535c7cd RDI: 0000000000000246
[ 200.485313] RBP: ffffffffffffffff R08: 0000000000000000 R09: 0000000000000000
[ 200.485917] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000144001
[ 200.486523] R13: 00007ffd6ba55f48 R14: 00007ffd6ba55f40 R15: ffffb139401cbf08
[ 200.487130] FS: 00007f68df717580(0000) GS:ffff9ec77fa00000(0000) knlGS:0000000000000000
[ 200.487804] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 200.488295] CR2: fffffffffffffffe CR3: 0000000135d48000 CR4: 00000000000006f0
[ 200.488897] Call Trace:
[ 200.489115] kpageflags_read+0xe9/0x140
[ 200.489447] proc_reg_read+0x3c/0x60
[ 200.489755] vfs_read+0xc2/0x170
[ 200.490037] ksys_pread64+0x65/0xa0
[ 200.490352] do_syscall_64+0x5c/0xa0
[ 200.490665] entry_SYSCALL_64_after_hwframe+0x49/0xbe
But it can be triggered much easier via "cat /proc/kpageflags > /dev/null"
after cold/hot plugging a DIMM to such a system:
[root@localhost ~]# cat /proc/kpageflags > /dev/null
[ 111.517275] BUG: unable to handle page fault for address: fffffffffffffffe
[ 111.517907] #PF: supervisor read access in kernel mode
[ 111.518333] #PF: error_code(0x0000) - not-present page
[ 111.518771] PGD a240e067 P4D a240e067 PUD a2410067 PMD 0
This patch fixes that by at least zero-ing out that memmap (so e.g.,
page_to_pfn() will not crash). Commit 907ec5fca3 ("mm: zero remaining
unavailable struct pages") tried to fix a similar issue, but forgot to
consider this special case.
After this patch, there are still problems to solve. E.g., not all of
these pages falling into a memory hole will actually get initialized later
and set PageReserved - they are only zeroed out - but at least the
immediate crashes are gone. A follow-up patch will take care of this.
Link: http://lkml.kernel.org/r/20191211163201.17179-2-david@redhat.com
Fixes: f7f99100d8 ("mm: stop zeroing memory during allocation in vmemmap")
Signed-off-by: David Hildenbrand <david@redhat.com>
Tested-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Bob Picco <bob.picco@oracle.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: <stable@vger.kernel.org> [4.15+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It makes sense to call the WARN_ON_ONCE(zone_idx(zone) == ZONE_MOVABLE)
from start_isolate_page_range(), but should avoid triggering it from
userspace, i.e, from is_mem_section_removable() because it could crash
the system by a non-root user if warn_on_panic is set.
While at it, simplify the code a bit by removing an unnecessary jump
label.
Link: http://lkml.kernel.org/r/20200120163915.1469-1-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Suggested-by: Michal Hocko <mhocko@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It is not that hard to trigger lockdep splats by calling printk from
under zone->lock. Most of them are false positives caused by lock
chains introduced early in the boot process and they do not cause any
real problems (although most of the early boot lock dependencies could
happen after boot as well). There are some console drivers which do
allocate from the printk context as well and those should be fixed. In
any case, false positives are not that trivial to workaround and it is
far from optimal to lose lockdep functionality for something that is a
non-issue.
So change has_unmovable_pages() so that it no longer calls dump_page()
itself - instead it returns a "struct page *" of the unmovable page back
to the caller so that in the case of a has_unmovable_pages() failure,
the caller can call dump_page() after releasing zone->lock. Also, make
dump_page() is able to report a CMA page as well, so the reason string
from has_unmovable_pages() can be removed.
Even though has_unmovable_pages doesn't hold any reference to the
returned page this should be reasonably safe for the purpose of
reporting the page (dump_page) because it cannot be hotremoved in the
context of memory unplug. The state of the page might change but that
is the case even with the existing code as zone->lock only plays role
for free pages.
While at it, remove a similar but unnecessary debug-only printk() as
well. A sample of one of those lockdep splats is,
WARNING: possible circular locking dependency detected
------------------------------------------------------
test.sh/8653 is trying to acquire lock:
ffffffff865a4460 (console_owner){-.-.}, at:
console_unlock+0x207/0x750
but task is already holding lock:
ffff88883fff3c58 (&(&zone->lock)->rlock){-.-.}, at:
__offline_isolated_pages+0x179/0x3e0
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (&(&zone->lock)->rlock){-.-.}:
__lock_acquire+0x5b3/0xb40
lock_acquire+0x126/0x280
_raw_spin_lock+0x2f/0x40
rmqueue_bulk.constprop.21+0xb6/0x1160
get_page_from_freelist+0x898/0x22c0
__alloc_pages_nodemask+0x2f3/0x1cd0
alloc_pages_current+0x9c/0x110
allocate_slab+0x4c6/0x19c0
new_slab+0x46/0x70
___slab_alloc+0x58b/0x960
__slab_alloc+0x43/0x70
__kmalloc+0x3ad/0x4b0
__tty_buffer_request_room+0x100/0x250
tty_insert_flip_string_fixed_flag+0x67/0x110
pty_write+0xa2/0xf0
n_tty_write+0x36b/0x7b0
tty_write+0x284/0x4c0
__vfs_write+0x50/0xa0
vfs_write+0x105/0x290
redirected_tty_write+0x6a/0xc0
do_iter_write+0x248/0x2a0
vfs_writev+0x106/0x1e0
do_writev+0xd4/0x180
__x64_sys_writev+0x45/0x50
do_syscall_64+0xcc/0x76c
entry_SYSCALL_64_after_hwframe+0x49/0xbe
-> #2 (&(&port->lock)->rlock){-.-.}:
__lock_acquire+0x5b3/0xb40
lock_acquire+0x126/0x280
_raw_spin_lock_irqsave+0x3a/0x50
tty_port_tty_get+0x20/0x60
tty_port_default_wakeup+0xf/0x30
tty_port_tty_wakeup+0x39/0x40
uart_write_wakeup+0x2a/0x40
serial8250_tx_chars+0x22e/0x440
serial8250_handle_irq.part.8+0x14a/0x170
serial8250_default_handle_irq+0x5c/0x90
serial8250_interrupt+0xa6/0x130
__handle_irq_event_percpu+0x78/0x4f0
handle_irq_event_percpu+0x70/0x100
handle_irq_event+0x5a/0x8b
handle_edge_irq+0x117/0x370
do_IRQ+0x9e/0x1e0
ret_from_intr+0x0/0x2a
cpuidle_enter_state+0x156/0x8e0
cpuidle_enter+0x41/0x70
call_cpuidle+0x5e/0x90
do_idle+0x333/0x370
cpu_startup_entry+0x1d/0x1f
start_secondary+0x290/0x330
secondary_startup_64+0xb6/0xc0
-> #1 (&port_lock_key){-.-.}:
__lock_acquire+0x5b3/0xb40
lock_acquire+0x126/0x280
_raw_spin_lock_irqsave+0x3a/0x50
serial8250_console_write+0x3e4/0x450
univ8250_console_write+0x4b/0x60
console_unlock+0x501/0x750
vprintk_emit+0x10d/0x340
vprintk_default+0x1f/0x30
vprintk_func+0x44/0xd4
printk+0x9f/0xc5
-> #0 (console_owner){-.-.}:
check_prev_add+0x107/0xea0
validate_chain+0x8fc/0x1200
__lock_acquire+0x5b3/0xb40
lock_acquire+0x126/0x280
console_unlock+0x269/0x750
vprintk_emit+0x10d/0x340
vprintk_default+0x1f/0x30
vprintk_func+0x44/0xd4
printk+0x9f/0xc5
__offline_isolated_pages.cold.52+0x2f/0x30a
offline_isolated_pages_cb+0x17/0x30
walk_system_ram_range+0xda/0x160
__offline_pages+0x79c/0xa10
offline_pages+0x11/0x20
memory_subsys_offline+0x7e/0xc0
device_offline+0xd5/0x110
state_store+0xc6/0xe0
dev_attr_store+0x3f/0x60
sysfs_kf_write+0x89/0xb0
kernfs_fop_write+0x188/0x240
__vfs_write+0x50/0xa0
vfs_write+0x105/0x290
ksys_write+0xc6/0x160
__x64_sys_write+0x43/0x50
do_syscall_64+0xcc/0x76c
entry_SYSCALL_64_after_hwframe+0x49/0xbe
other info that might help us debug this:
Chain exists of:
console_owner --> &(&port->lock)->rlock --> &(&zone->lock)->rlock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&(&zone->lock)->rlock);
lock(&(&port->lock)->rlock);
lock(&(&zone->lock)->rlock);
lock(console_owner);
*** DEADLOCK ***
9 locks held by test.sh/8653:
#0: ffff88839ba7d408 (sb_writers#4){.+.+}, at:
vfs_write+0x25f/0x290
#1: ffff888277618880 (&of->mutex){+.+.}, at:
kernfs_fop_write+0x128/0x240
#2: ffff8898131fc218 (kn->count#115){.+.+}, at:
kernfs_fop_write+0x138/0x240
#3: ffffffff86962a80 (device_hotplug_lock){+.+.}, at:
lock_device_hotplug_sysfs+0x16/0x50
#4: ffff8884374f4990 (&dev->mutex){....}, at:
device_offline+0x70/0x110
#5: ffffffff86515250 (cpu_hotplug_lock.rw_sem){++++}, at:
__offline_pages+0xbf/0xa10
#6: ffffffff867405f0 (mem_hotplug_lock.rw_sem){++++}, at:
percpu_down_write+0x87/0x2f0
#7: ffff88883fff3c58 (&(&zone->lock)->rlock){-.-.}, at:
__offline_isolated_pages+0x179/0x3e0
#8: ffffffff865a4920 (console_lock){+.+.}, at:
vprintk_emit+0x100/0x340
stack backtrace:
Hardware name: HPE ProLiant DL560 Gen10/ProLiant DL560 Gen10,
BIOS U34 05/21/2019
Call Trace:
dump_stack+0x86/0xca
print_circular_bug.cold.31+0x243/0x26e
check_noncircular+0x29e/0x2e0
check_prev_add+0x107/0xea0
validate_chain+0x8fc/0x1200
__lock_acquire+0x5b3/0xb40
lock_acquire+0x126/0x280
console_unlock+0x269/0x750
vprintk_emit+0x10d/0x340
vprintk_default+0x1f/0x30
vprintk_func+0x44/0xd4
printk+0x9f/0xc5
__offline_isolated_pages.cold.52+0x2f/0x30a
offline_isolated_pages_cb+0x17/0x30
walk_system_ram_range+0xda/0x160
__offline_pages+0x79c/0xa10
offline_pages+0x11/0x20
memory_subsys_offline+0x7e/0xc0
device_offline+0xd5/0x110
state_store+0xc6/0xe0
dev_attr_store+0x3f/0x60
sysfs_kf_write+0x89/0xb0
kernfs_fop_write+0x188/0x240
__vfs_write+0x50/0xa0
vfs_write+0x105/0x290
ksys_write+0xc6/0x160
__x64_sys_write+0x43/0x50
do_syscall_64+0xcc/0x76c
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Link: http://lkml.kernel.org/r/20200117181200.20299-1-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that the memory isolate notifier is gone, the parameter is always 0.
Drop it and cleanup has_unmovable_pages().
Link: http://lkml.kernel.org/r/20191114131911.11783-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Pingfan Liu <kernelfans@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
memmap_init_zone() can be called on the ranges with holes during the
boot. It will skip any non-valid PFNs one-by-one. It works fine as
long as holes are not too big.
But huge holes in the memory map causes a problem. It takes over 20
seconds to walk 32TiB hole. x86-64 with 5-level paging allows for much
larger holes in the memory map which would practically hang the system.
Deferred struct page init doesn't help here. It only works on the
present ranges.
Skipping non-present sections would fix the issue.
Link: http://lkml.kernel.org/r/20191230093828.24613-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: "Jin, Zhi" <zhi.jin@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 96a2b03f28 ("mm, debug_pagelloc: use static keys to enable
debugging") has introduced a static key to reduce overhead when
debug_pagealloc is compiled in but not enabled. It relied on the
assumption that jump_label_init() is called before parse_early_param()
as in start_kernel(), so when the "debug_pagealloc=on" option is parsed,
it is safe to enable the static key.
However, it turns out multiple architectures call parse_early_param()
earlier from their setup_arch(). x86 also calls jump_label_init() even
earlier, so no issue was found while testing the commit, but same is not
true for e.g. ppc64 and s390 where the kernel would not boot with
debug_pagealloc=on as found by our QA.
To fix this without tricky changes to init code of multiple
architectures, this patch partially reverts the static key conversion
from 96a2b03f28. Init-time and non-fastpath calls (such as in arch
code) of debug_pagealloc_enabled() will again test a simple bool
variable. Fastpath mm code is converted to a new
debug_pagealloc_enabled_static() variant that relies on the static key,
which is enabled in a well-defined point in mm_init() where it's
guaranteed that jump_label_init() has been called, regardless of
architecture.
[sfr@canb.auug.org.au: export _debug_pagealloc_enabled_early]
Link: http://lkml.kernel.org/r/20200106164944.063ac07b@canb.auug.org.au
Link: http://lkml.kernel.org/r/20191219130612.23171-1-vbabka@suse.cz
Fixes: 96a2b03f28 ("mm, debug_pagelloc: use static keys to enable debugging")
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Qian Cai <cai@lca.pw>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
THP page faults now attempt a __GFP_THISNODE allocation first, which
should only compact existing free memory, followed by another attempt
that can allocate from any node using reclaim/compaction effort
specified by global defrag setting and madvise.
This patch makes the following changes to the scheme:
- Before the patch, the first allocation relies on a check for
pageblock order and __GFP_IO to prevent excessive reclaim. This
however affects also the second attempt, which is not limited to
single node.
Instead of that, reuse the existing check for costly order
__GFP_NORETRY allocations, and make sure the first THP attempt uses
__GFP_NORETRY. As a side-effect, all costly order __GFP_NORETRY
allocations will bail out if compaction needs reclaim, while
previously they only bailed out when compaction was deferred due to
previous failures.
This should be still acceptable within the __GFP_NORETRY semantics.
- Before the patch, the second allocation attempt (on all nodes) was
passing __GFP_NORETRY. This is redundant as the check for pageblock
order (discussed above) was stronger. It's also contrary to
madvise(MADV_HUGEPAGE) which means some effort to allocate THP is
requested.
After this patch, the second attempt doesn't pass __GFP_THISNODE nor
__GFP_NORETRY.
To sum up, THP page faults now try the following attempts:
1. local node only THP allocation with no reclaim, just compaction.
2. for madvised VMA's or when synchronous compaction is enabled always - THP
allocation from any node with effort determined by global defrag setting
and VMA madvise
3. fallback to base pages on any node
Link: http://lkml.kernel.org/r/08a3f4dd-c3ce-0009-86c5-9ee51aba8557@suse.cz
Fixes: b39d0ee263 ("mm, page_alloc: avoid expensive reclaim when compaction may not succeed")
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a per-memcg lruvec and a NUMA node lruvec. Which one is being
used is somewhat confusing right now, and it's easy to make mistakes -
especially when it comes to global reclaim.
How it works: when memory cgroups are enabled, we always use the
root_mem_cgroup's per-node lruvecs. When memory cgroups are not compiled
in or disabled at runtime, we use pgdat->lruvec.
Document that in a comment.
Due to the way the reclaim code is generalized, all lookups use the
mem_cgroup_lruvec() helper function, and nobody should have to find the
right lruvec manually right now. But to avoid future mistakes, rename the
pgdat->lruvec member to pgdat->__lruvec and delete the convenience wrapper
that suggests it's a commonly accessed member.
While in this area, swap the mem_cgroup_lruvec() argument order. The name
suggests a memcg operation, yet it takes a pgdat first and a memcg second.
I have to double take every time I call this. Fix that.
Link: http://lkml.kernel.org/r/20191022144803.302233-3-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Print nr_reserved_highatomic in show_free_areas, because when alloc_harder
is false, this value will be subtracted from the free_pages in
__zone_watermark_ok. Printing this value can help analyze memory
allocaction failure issues.
Link: http://lkml.kernel.org/r/19515f3de2fb6abe66b52e03e4b676a21e82beda.1573634806.git.lijiazi@xiaomi.com
Signed-off-by: lijiazi <lijiazi@xiaomi.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Both the percpu_pagelist_fraction sysctl handler and memory hotplug have
a common requirement of updating the pcpu page allocation batch and high
values. Split the relevant helper to share common code.
No functional change.
Link: http://lkml.kernel.org/r/20191021094808.28824-3-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Qian Cai <cai@lca.pw>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
HugeTLB helper alloc_gigantic_page() implements fairly generic
allocation method where it scans over various zones looking for a large
contiguous pfn range before trying to allocate it with
alloc_contig_range().
Other than deriving the requested order from 'struct hstate', there is
nothing HugeTLB specific in there. This can be made available for
general use to allocate contiguous memory which could not have been
allocated through the buddy allocator.
alloc_gigantic_page() has been split carving out actual allocation
method which is then made available via new alloc_contig_pages() helper
wrapped under CONFIG_CONTIG_ALLOC. All references to 'gigantic' have
been replaced with more generic term 'contig'. Allocated pages here
should be freed with free_contig_range() or by calling __free_page() on
each allocated page.
Link: http://lkml.kernel.org/r/1571300646-32240-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We have two types of users of page isolation:
1. Memory offlining: Offline memory so it can be unplugged. Memory
won't be touched.
2. Memory allocation: Allocate memory (e.g., alloc_contig_range()) to
become the owner of the memory and make use of
it.
For example, in case we want to offline memory, we can ignore (skip
over) PageHWPoison() pages, as the memory won't get used. We can allow
to offline memory. In contrast, we don't want to allow to allocate such
memory.
Let's generalize the approach so we can special case other types of
pages we want to skip over in case we offline memory. While at it, also
pass the same flags to test_pages_isolated().
Link: http://lkml.kernel.org/r/20191021172353.3056-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Suggested-by: Michal Hocko <mhocko@suse.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Pingfan Liu <kernelfans@gmail.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm: Memory offlining + page isolation cleanups", v2.
This patch (of 2):
We call __offline_isolated_pages() from __offline_pages() after all
pages were isolated and are either free (PageBuddy()) or PageHWPoison.
Nothing can stop us from offlining memory at this point.
In __offline_isolated_pages() we first set all affected memory sections
offline (offline_mem_sections(pfn, end_pfn)), to mark the memmap as
invalid (pfn_to_online_page() will no longer succeed), and then walk
over all pages to pull the free pages from the free lists (to the
isolated free lists, to be precise).
Note that re-onlining a memory block will result in the whole memmap
getting reinitialized, overwriting any old state. We already poision
the memmap when offlining is complete to find any access to
stale/uninitialized memmaps.
So, setting the pages PageReserved() is not helpful. The memap is
marked offline and all pageblocks are isolated. As soon as offline, the
memmap is stale either way.
This looks like a leftover from ancient times where we initialized the
memmap when adding memory and not when onlining it (the pages were set
PageReserved so re-onling would work as expected).
Link: http://lkml.kernel.org/r/20191021172353.3056-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Pingfan Liu <kernelfans@gmail.com>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
While investigating a bug related to higher atomic allocation failures,
we noticed the failure warnings positively drowning the console, and in
our case trigger lockup warnings because of a serial console too slow to
handle all that output.
But even if we had a faster console, it's unclear what additional
information the current level of repetition provides.
Allocation failures happen for three reasons: The machine is OOM, the VM
is failing to handle reasonable requests, or somebody is making
unreasonable requests (and didn't acknowledge their opportunism with
__GFP_NOWARN). Having the memory dump, a callstack, and the ratelimit
stats on skipped failure warnings should provide enough information to
let users/admins/developers know whether something is wrong and point
them in the right direction for debugging, bpftracing etc.
Limit allocation failure warnings to one spew every ten seconds.
Link: http://lkml.kernel.org/r/20191028194906.26899-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Deferred memory initialisation updates zone->managed_pages during the
initialisation phase but before that finishes, the per-cpu page
allocator (pcpu) calculates the number of pages allocated/freed in
batches as well as the maximum number of pages allowed on a per-cpu
list. As zone->managed_pages is not up to date yet, the pcpu
initialisation calculates inappropriately low batch and high values.
This increases zone lock contention quite severely in some cases with
the degree of severity depending on how many CPUs share a local zone and
the size of the zone. A private report indicated that kernel build
times were excessive with extremely high system CPU usage. A perf
profile indicated that a large chunk of time was lost on zone->lock
contention.
This patch recalculates the pcpu batch and high values after deferred
initialisation completes for every populated zone in the system. It was
tested on a 2-socket AMD EPYC 2 machine using a kernel compilation
workload -- allmodconfig and all available CPUs.
mmtests configuration: config-workload-kernbench-max Configuration was
modified to build on a fresh XFS partition.
kernbench
5.4.0-rc3 5.4.0-rc3
vanilla resetpcpu-v2
Amean user-256 13249.50 ( 0.00%) 16401.31 * -23.79%*
Amean syst-256 14760.30 ( 0.00%) 4448.39 * 69.86%*
Amean elsp-256 162.42 ( 0.00%) 119.13 * 26.65%*
Stddev user-256 42.97 ( 0.00%) 19.15 ( 55.43%)
Stddev syst-256 336.87 ( 0.00%) 6.71 ( 98.01%)
Stddev elsp-256 2.46 ( 0.00%) 0.39 ( 84.03%)
5.4.0-rc3 5.4.0-rc3
vanilla resetpcpu-v2
Duration User 39766.24 49221.79
Duration System 44298.10 13361.67
Duration Elapsed 519.11 388.87
The patch reduces system CPU usage by 69.86% and total build time by
26.65%. The variance of system CPU usage is also much reduced.
Before, this was the breakdown of batch and high values over all zones
was:
256 batch: 1
256 batch: 63
512 batch: 7
256 high: 0
256 high: 378
512 high: 42
512 pcpu pagesets had a batch limit of 7 and a high limit of 42. After
the patch:
256 batch: 1
768 batch: 63
256 high: 0
768 high: 378
[mgorman@techsingularity.net: fix merge/linkage snafu]
Link: http://lkml.kernel.org/r/20191023084705.GD3016@techsingularity.netLink: http://lkml.kernel.org/r/20191021094808.28824-2-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Qian Cai <cai@lca.pw>
Cc: <stable@vger.kernel.org> [4.1+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit b39d0ee263 ("mm, page_alloc: avoid expensive reclaim when
compaction may not succeed") has chnaged the allocator to bail out from
the allocator early to prevent from a potentially excessive memory
reclaim. __GFP_RETRY_MAYFAIL is designed to retry the allocation,
reclaim and compaction loop as long as there is a reasonable chance to
make forward progress. Neither COMPACT_SKIPPED nor COMPACT_DEFERRED at
the INIT_COMPACT_PRIORITY compaction attempt gives this feedback.
The most obvious affected subsystem is hugetlbfs which allocates huge
pages based on an admin request (or via admin configured overcommit). I
have done a simple test which tries to allocate half of the memory for
hugetlb pages while the memory is full of a clean page cache. This is
not an unusual situation because we try to cache as much of the memory
as possible and sysctl/sysfs interface to allocate huge pages is there
for flexibility to allocate hugetlb pages at any time.
System has 1GB of RAM and we are requesting 515MB worth of hugetlb pages
after the memory is prefilled by a clean page cache:
root@test1:~# cat hugetlb_test.sh
set -x
echo 0 > /proc/sys/vm/nr_hugepages
echo 3 > /proc/sys/vm/drop_caches
echo 1 > /proc/sys/vm/compact_memory
dd if=/mnt/data/file-1G of=/dev/null bs=$((4<<10))
TS=$(date +%s)
echo 256 > /proc/sys/vm/nr_hugepages
cat /proc/sys/vm/nr_hugepages
The results for 2 consecutive runs on clean 5.3
root@test1:~# sh hugetlb_test.sh
+ echo 0
+ echo 3
+ echo 1
+ dd if=/mnt/data/file-1G of=/dev/null bs=4096
262144+0 records in
262144+0 records out
1073741824 bytes (1.1 GB) copied, 21.0694 s, 51.0 MB/s
+ date +%s
+ TS=1569905284
+ echo 256
+ cat /proc/sys/vm/nr_hugepages
256
root@test1:~# sh hugetlb_test.sh
+ echo 0
+ echo 3
+ echo 1
+ dd if=/mnt/data/file-1G of=/dev/null bs=4096
262144+0 records in
262144+0 records out
1073741824 bytes (1.1 GB) copied, 21.7548 s, 49.4 MB/s
+ date +%s
+ TS=1569905311
+ echo 256
+ cat /proc/sys/vm/nr_hugepages
256
Now with b39d0ee263 applied
root@test1:~# sh hugetlb_test.sh
+ echo 0
+ echo 3
+ echo 1
+ dd if=/mnt/data/file-1G of=/dev/null bs=4096
262144+0 records in
262144+0 records out
1073741824 bytes (1.1 GB) copied, 20.1815 s, 53.2 MB/s
+ date +%s
+ TS=1569905516
+ echo 256
+ cat /proc/sys/vm/nr_hugepages
11
root@test1:~# sh hugetlb_test.sh
+ echo 0
+ echo 3
+ echo 1
+ dd if=/mnt/data/file-1G of=/dev/null bs=4096
262144+0 records in
262144+0 records out
1073741824 bytes (1.1 GB) copied, 21.9485 s, 48.9 MB/s
+ date +%s
+ TS=1569905541
+ echo 256
+ cat /proc/sys/vm/nr_hugepages
12
The success rate went down by factor of 20!
Although hugetlb allocation requests might fail and it is reasonable to
expect them to under extremely fragmented memory or when the memory is
under a heavy pressure but the above situation is not that case.
Fix the regression by reverting back to the previous behavior for
__GFP_RETRY_MAYFAIL requests and disable the beail out heuristic for
those requests.
Mike said:
: hugetlbfs allocations are commonly done via sysctl/sysfs shortly after
: boot where this may not be as much of an issue. However, I am aware of at
: least three use cases where allocations are made after the system has been
: up and running for quite some time:
:
: - DB reconfiguration. If sysctl/sysfs fails to get required number of
: huge pages, system is rebooted to perform allocation after boot.
:
: - VM provisioning. If unable get required number of huge pages, fall
: back to base pages.
:
: - An application that does not preallocate pool, but rather allocates
: pages at fault time for optimal NUMA locality.
:
: In all cases, I would expect b39d0ee263 to cause regressions and
: noticable behavior changes.
:
: My quick/limited testing in
: https://lkml.kernel.org/r/3468b605-a3a9-6978-9699-57c52a90bd7e@oracle.com
: was insufficient. It was also mentioned that if something like
: b39d0ee263 went forward, I would like exemptions for __GFP_RETRY_MAYFAIL
: requests as in this patch.
[mhocko@suse.com: reworded changelog]
Link: http://lkml.kernel.org/r/20191007075548.12456-1-mhocko@kernel.org
Fixes: b39d0ee263 ("mm, page_alloc: avoid expensive reclaim when compaction may not succeed")
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge hugepage allocation updates from David Rientjes:
"We (mostly Linus, Andrea, and myself) have been discussing offlist how
to implement a sane default allocation strategy for hugepages on NUMA
platforms.
With these reverts in place, the page allocator will happily allocate
a remote hugepage immediately rather than try to make a local hugepage
available. This incurs a substantial performance degradation when
memory compaction would have otherwise made a local hugepage
available.
This series reverts those reverts and attempts to propose a more sane
default allocation strategy specifically for hugepages. Andrea
acknowledges this is likely to fix the swap storms that he originally
reported that resulted in the patches that removed __GFP_THISNODE from
hugepage allocations.
The immediate goal is to return 5.3 to the behavior the kernel has
implemented over the past several years so that remote hugepages are
not immediately allocated when local hugepages could have been made
available because the increased access latency is untenable.
The next goal is to introduce a sane default allocation strategy for
hugepages allocations in general regardless of the configuration of
the system so that we prevent thrashing of local memory when
compaction is unlikely to succeed and can prefer remote hugepages over
remote native pages when the local node is low on memory."
Note on timing: this reverts the hugepage VM behavior changes that got
introduced fairly late in the 5.3 cycle, and that fixed a huge
performance regression for certain loads that had been around since
4.18.
Andrea had this note:
"The regression of 4.18 was that it was taking hours to start a VM
where 3.10 was only taking a few seconds, I reported all the details
on lkml when it was finally tracked down in August 2018.
https://lore.kernel.org/linux-mm/20180820032640.9896-2-aarcange@redhat.com/
__GFP_THISNODE in MADV_HUGEPAGE made the above enterprise vfio
workload degrade like in the "current upstream" above. And it still
would have been that bad as above until 5.3-rc5"
where the bad behavior ends up happening as you fill up a local node,
and without that change, you'd get into the nasty swap storm behavior
due to compaction working overtime to make room for more memory on the
nodes.
As a result 5.3 got the two performance fix reverts in rc5.
However, David Rientjes then noted that those performance fixes in turn
regressed performance for other loads - although not quite to the same
degree. He suggested reverting the reverts and instead replacing them
with two small changes to how hugepage allocations are done (patch
descriptions rephrased by me):
- "avoid expensive reclaim when compaction may not succeed": just admit
that the allocation failed when you're trying to allocate a huge-page
and compaction wasn't successful.
- "allow hugepage fallback to remote nodes when madvised": when that
node-local huge-page allocation failed, retry without forcing the
local node.
but by then I judged it too late to replace the fixes for a 5.3 release.
So 5.3 was released with behavior that harked back to the pre-4.18 logic.
But now we're in the merge window for 5.4, and we can see if this
alternate model fixes not just the horrendous swap storm behavior, but
also restores the performance regression that the late reverts caused.
Fingers crossed.
* emailed patches from David Rientjes <rientjes@google.com>:
mm, page_alloc: allow hugepage fallback to remote nodes when madvised
mm, page_alloc: avoid expensive reclaim when compaction may not succeed
Revert "Revert "Revert "mm, thp: consolidate THP gfp handling into alloc_hugepage_direct_gfpmask""
Revert "Revert "mm, thp: restore node-local hugepage allocations""
Memory compaction has a couple significant drawbacks as the allocation
order increases, specifically:
- isolate_freepages() is responsible for finding free pages to use as
migration targets and is implemented as a linear scan of memory
starting at the end of a zone,
- failing order-0 watermark checks in memory compaction does not account
for how far below the watermarks the zone actually is: to enable
migration, there must be *some* free memory available. Per the above,
watermarks are not always suffficient if isolate_freepages() cannot
find the free memory but it could require hundreds of MBs of reclaim to
even reach this threshold (read: potentially very expensive reclaim with
no indication compaction can be successful), and
- if compaction at this order has failed recently so that it does not even
run as a result of deferred compaction, looping through reclaim can often
be pointless.
For hugepage allocations, these are quite substantial drawbacks because
these are very high order allocations (order-9 on x86) and falling back to
doing reclaim can potentially be *very* expensive without any indication
that compaction would even be successful.
Reclaim itself is unlikely to free entire pageblocks and certainly no
reliance should be put on it to do so in isolation (recall lumpy reclaim).
This means we should avoid reclaim and simply fail hugepage allocation if
compaction is deferred.
It is also not helpful to thrash a zone by doing excessive reclaim if
compaction may not be able to access that memory. If order-0 watermarks
fail and the allocation order is sufficiently large, it is likely better
to fail the allocation rather than thrashing the zone.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Stefan Priebe - Profihost AG <s.priebe@profihost.ag>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A later patch makes THP deferred split shrinker memcg aware, but it needs
page->mem_cgroup information in THP destructor, which is called after
mem_cgroup_uncharge() now.
So move mem_cgroup_uncharge() from __page_cache_release() to compound page
destructor, which is called by both THP and other compound pages except
HugeTLB. And call it in __put_single_page() for single order page.
Link: http://lkml.kernel.org/r/1565144277-36240-3-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Suggested-by: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "Make deferred split shrinker memcg aware", v6.
Currently THP deferred split shrinker is not memcg aware, this may cause
premature OOM with some configuration. For example the below test would
run into premature OOM easily:
$ cgcreate -g memory:thp
$ echo 4G > /sys/fs/cgroup/memory/thp/memory/limit_in_bytes
$ cgexec -g memory:thp transhuge-stress 4000
transhuge-stress comes from kernel selftest.
It is easy to hit OOM, but there are still a lot THP on the deferred split
queue, memcg direct reclaim can't touch them since the deferred split
shrinker is not memcg aware.
Convert deferred split shrinker memcg aware by introducing per memcg
deferred split queue. The THP should be on either per node or per memcg
deferred split queue if it belongs to a memcg. When the page is
immigrated to the other memcg, it will be immigrated to the target memcg's
deferred split queue too.
Reuse the second tail page's deferred_list for per memcg list since the
same THP can't be on multiple deferred split queues.
Make deferred split shrinker not depend on memcg kmem since it is not
slab. It doesn't make sense to not shrink THP even though memcg kmem is
disabled.
With the above change the test demonstrated above doesn't trigger OOM even
though with cgroup.memory=nokmem.
This patch (of 4):
Put split_queue, split_queue_lock and split_queue_len into a struct in
order to reduce code duplication when we convert deferred_split to memcg
aware in the later patches.
Link: http://lkml.kernel.org/r/1565144277-36240-2-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Suggested-by: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Kravetz reports that "hugetlb allocations could stall for minutes or
hours when should_compact_retry() would return true more often then it
should. Specifically, this was in the case where compact_result was
COMPACT_DEFERRED and COMPACT_PARTIAL_SKIPPED and no progress was being
made."
The problem is that the compaction_withdrawn() test in
should_compact_retry() includes compaction outcomes that are only possible
on low compaction priority, and results in a retry without increasing the
priority. This may result in furter reclaim, and more incomplete
compaction attempts.
With this patch, compaction priority is raised when possible, or
should_compact_retry() returns false.
The COMPACT_SKIPPED result doesn't really fit together with the other
outcomes in compaction_withdrawn(), as that's a result caused by
insufficient order-0 pages, not due to low compaction priority. With this
patch, it is moved to a new compaction_needs_reclaim() function, and for
that outcome we keep the current logic of retrying if it looks like
reclaim will be able to help.
Link: http://lkml.kernel.org/r/20190806014744.15446-4-mike.kravetz@oracle.com
Reported-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Tested-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replace 1 << compound_order(page) with compound_nr(page). Minor
improvements in readability.
Link: http://lkml.kernel.org/r/20190721104612.19120-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is more cleanup and consolidation of the hmm APIs and the very
strongly related mmu_notifier interfaces. Many places across the tree
using these interfaces are touched in the process. Beyond that a cleanup
to the page walker API and a few memremap related changes round out the
series:
- General improvement of hmm_range_fault() and related APIs, more
documentation, bug fixes from testing, API simplification &
consolidation, and unused API removal
- Simplify the hmm related kconfigs to HMM_MIRROR and DEVICE_PRIVATE, and
make them internal kconfig selects
- Hoist a lot of code related to mmu notifier attachment out of drivers by
using a refcount get/put attachment idiom and remove the convoluted
mmu_notifier_unregister_no_release() and related APIs.
- General API improvement for the migrate_vma API and revision of its only
user in nouveau
- Annotate mmu_notifiers with lockdep and sleeping region debugging
Two series unrelated to HMM or mmu_notifiers came along due to
dependencies:
- Allow pagemap's memremap_pages family of APIs to work without providing
a struct device
- Make walk_page_range() and related use a constant structure for function
pointers
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Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma
Pull hmm updates from Jason Gunthorpe:
"This is more cleanup and consolidation of the hmm APIs and the very
strongly related mmu_notifier interfaces. Many places across the tree
using these interfaces are touched in the process. Beyond that a
cleanup to the page walker API and a few memremap related changes
round out the series:
- General improvement of hmm_range_fault() and related APIs, more
documentation, bug fixes from testing, API simplification &
consolidation, and unused API removal
- Simplify the hmm related kconfigs to HMM_MIRROR and DEVICE_PRIVATE,
and make them internal kconfig selects
- Hoist a lot of code related to mmu notifier attachment out of
drivers by using a refcount get/put attachment idiom and remove the
convoluted mmu_notifier_unregister_no_release() and related APIs.
- General API improvement for the migrate_vma API and revision of its
only user in nouveau
- Annotate mmu_notifiers with lockdep and sleeping region debugging
Two series unrelated to HMM or mmu_notifiers came along due to
dependencies:
- Allow pagemap's memremap_pages family of APIs to work without
providing a struct device
- Make walk_page_range() and related use a constant structure for
function pointers"
* tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (75 commits)
libnvdimm: Enable unit test infrastructure compile checks
mm, notifier: Catch sleeping/blocking for !blockable
kernel.h: Add non_block_start/end()
drm/radeon: guard against calling an unpaired radeon_mn_unregister()
csky: add missing brackets in a macro for tlb.h
pagewalk: use lockdep_assert_held for locking validation
pagewalk: separate function pointers from iterator data
mm: split out a new pagewalk.h header from mm.h
mm/mmu_notifiers: annotate with might_sleep()
mm/mmu_notifiers: prime lockdep
mm/mmu_notifiers: add a lockdep map for invalidate_range_start/end
mm/mmu_notifiers: remove the __mmu_notifier_invalidate_range_start/end exports
mm/hmm: hmm_range_fault() infinite loop
mm/hmm: hmm_range_fault() NULL pointer bug
mm/hmm: fix hmm_range_fault()'s handling of swapped out pages
mm/mmu_notifiers: remove unregister_no_release
RDMA/odp: remove ib_ucontext from ib_umem
RDMA/odp: use mmu_notifier_get/put for 'struct ib_ucontext_per_mm'
RDMA/mlx5: Use odp instead of mr->umem in pagefault_mr
RDMA/mlx5: Use ib_umem_start instead of umem.address
...
Pull scheduler updates from Ingo Molnar:
- MAINTAINERS: Add Mark Rutland as perf submaintainer, Juri Lelli and
Vincent Guittot as scheduler submaintainers. Add Dietmar Eggemann,
Steven Rostedt, Ben Segall and Mel Gorman as scheduler reviewers.
As perf and the scheduler is getting bigger and more complex,
document the status quo of current responsibilities and interests,
and spread the review pain^H^H^H^H fun via an increase in the Cc:
linecount generated by scripts/get_maintainer.pl. :-)
- Add another series of patches that brings the -rt (PREEMPT_RT) tree
closer to mainline: split the monolithic CONFIG_PREEMPT dependencies
into a new CONFIG_PREEMPTION category that will allow the eventual
introduction of CONFIG_PREEMPT_RT. Still a few more hundred patches
to go though.
- Extend the CPU cgroup controller with uclamp.min and uclamp.max to
allow the finer shaping of CPU bandwidth usage.
- Micro-optimize energy-aware wake-ups from O(CPUS^2) to O(CPUS).
- Improve the behavior of high CPU count, high thread count
applications running under cpu.cfs_quota_us constraints.
- Improve balancing with SCHED_IDLE (SCHED_BATCH) tasks present.
- Improve CPU isolation housekeeping CPU allocation NUMA locality.
- Fix deadline scheduler bandwidth calculations and logic when cpusets
rebuilds the topology, or when it gets deadline-throttled while it's
being offlined.
- Convert the cpuset_mutex to percpu_rwsem, to allow it to be used from
setscheduler() system calls without creating global serialization.
Add new synchronization between cpuset topology-changing events and
the deadline acceptance tests in setscheduler(), which were broken
before.
- Rework the active_mm state machine to be less confusing and more
optimal.
- Rework (simplify) the pick_next_task() slowpath.
- Improve load-balancing on AMD EPYC systems.
- ... and misc cleanups, smaller fixes and improvements - please see
the Git log for more details.
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits)
sched/psi: Correct overly pessimistic size calculation
sched/fair: Speed-up energy-aware wake-ups
sched/uclamp: Always use 'enum uclamp_id' for clamp_id values
sched/uclamp: Update CPU's refcount on TG's clamp changes
sched/uclamp: Use TG's clamps to restrict TASK's clamps
sched/uclamp: Propagate system defaults to the root group
sched/uclamp: Propagate parent clamps
sched/uclamp: Extend CPU's cgroup controller
sched/topology: Improve load balancing on AMD EPYC systems
arch, ia64: Make NUMA select SMP
sched, perf: MAINTAINERS update, add submaintainers and reviewers
sched/fair: Use rq_lock/unlock in online_fair_sched_group
cpufreq: schedutil: fix equation in comment
sched: Rework pick_next_task() slow-path
sched: Allow put_prev_task() to drop rq->lock
sched/fair: Expose newidle_balance()
sched: Add task_struct pointer to sched_class::set_curr_task
sched: Rework CPU hotplug task selection
sched/{rt,deadline}: Fix set_next_task vs pick_next_task
sched: Fix kerneldoc comment for ia64_set_curr_task
...
SD_BALANCE_{FORK,EXEC} and SD_WAKE_AFFINE are stripped in sd_init()
for any sched domains with a NUMA distance greater than 2 hops
(RECLAIM_DISTANCE). The idea being that it's expensive to balance
across domains that far apart.
However, as is rather unfortunately explained in:
commit 32e45ff43e ("mm: increase RECLAIM_DISTANCE to 30")
the value for RECLAIM_DISTANCE is based on node distance tables from
2011-era hardware.
Current AMD EPYC machines have the following NUMA node distances:
node distances:
node 0 1 2 3 4 5 6 7
0: 10 16 16 16 32 32 32 32
1: 16 10 16 16 32 32 32 32
2: 16 16 10 16 32 32 32 32
3: 16 16 16 10 32 32 32 32
4: 32 32 32 32 10 16 16 16
5: 32 32 32 32 16 10 16 16
6: 32 32 32 32 16 16 10 16
7: 32 32 32 32 16 16 16 10
where 2 hops is 32.
The result is that the scheduler fails to load balance properly across
NUMA nodes on different sockets -- 2 hops apart.
For example, pinning 16 busy threads to NUMA nodes 0 (CPUs 0-7) and 4
(CPUs 32-39) like so,
$ numactl -C 0-7,32-39 ./spinner 16
causes all threads to fork and remain on node 0 until the active
balancer kicks in after a few seconds and forcibly moves some threads
to node 4.
Override node_reclaim_distance for AMD Zen.
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Suravee.Suthikulpanit@amd.com
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas.Lendacky@amd.com
Cc: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20190808195301.13222-3-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
After commit 907ec5fca3 ("mm: zero remaining unavailable struct
pages"), struct page of reserved memory is zeroed. This causes
page->flags to be 0 and fixes issues related to reading
/proc/kpageflags, for example, of reserved memory.
The VM_BUG_ON() in move_freepages_block(), however, assumes that
page_zone() is meaningful even for reserved memory. That assumption is
no longer true after the aforementioned commit.
There's no reason why move_freepages_block() should be testing the
legitimacy of page_zone() for reserved memory; its scope is limited only
to pages on the zone's freelist.
Note that pfn_valid() can be true for reserved memory: there is a
backing struct page. The check for page_to_nid(page) is also buggy but
reserved memory normally only appears on node 0 so the zeroing doesn't
affect this.
Move the debug checks to after verifying PageBuddy is true. This
isolates the scope of the checks to only be for buddy pages which are on
the zone's freelist which move_freepages_block() is operating on. In
this case, an incorrect node or zone is a bug worthy of being warned
about (and the examination of struct page is acceptable bcause this
memory is not reserved).
Why does move_freepages_block() gets called on reserved memory? It's
simply math after finding a valid free page from the per-zone free area
to use as fallback. We find the beginning and end of the pageblock of
the valid page and that can bring us into memory that was reserved per
the e820. pfn_valid() is still true (it's backed by a struct page), but
since it's zero'd we shouldn't make any inferences here about comparing
its node or zone. The current node check just happens to succeed most
of the time by luck because reserved memory typically appears on node 0.
The fix here is to validate that we actually have buddy pages before
testing if there's any type of zone or node strangeness going on.
We noticed it almost immediately after bringing 907ec5fca3 in on
CONFIG_DEBUG_VM builds. It depends on finding specific free pages in
the per-zone free area where the math in move_freepages() will bring the
start or end pfn into reserved memory and wanting to claim that entire
pageblock as a new migratetype. So the path will be rare, require
CONFIG_DEBUG_VM, and require fallback to a different migratetype.
Some struct pages were already zeroed from reserve pages before
907ec5fca3c so it theoretically could trigger before this commit. I
think it's rare enough under a config option that most people don't run
that others may not have noticed. I wouldn't argue against a stable tag
and the backport should be easy enough, but probably wouldn't single out
a commit that this is fixing.
Mel said:
: The overhead of the debugging check is higher with this patch although
: it'll only affect debug builds and the path is not particularly hot.
: If this was a concern, I think it would be reasonable to simply remove
: the debugging check as the zone boundaries are checked in
: move_freepages_block and we never expect a zone/node to be smaller than
: a pageblock and stuck in the middle of another zone.
Link: http://lkml.kernel.org/r/alpine.DEB.2.21.1908122036560.10779@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The dev field in struct dev_pagemap is only used to print dev_name in two
places, which are at best nice to have. Just remove the field and thus
the name in those two messages.
Link: https://lore.kernel.org/r/20190818090557.17853-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Bharata B Rao <bharata@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
The libnvdimm sub-system has suffered a series of hacks and broken
workarounds for the memory-hotplug implementation's awkward
section-aligned (128MB) granularity.
For example the following backtrace is emitted when attempting
arch_add_memory() with physical address ranges that intersect 'System
RAM' (RAM) with 'Persistent Memory' (PMEM) within a given section:
# cat /proc/iomem | grep -A1 -B1 Persistent\ Memory
100000000-1ffffffff : System RAM
200000000-303ffffff : Persistent Memory (legacy)
304000000-43fffffff : System RAM
440000000-23ffffffff : Persistent Memory
2400000000-43bfffffff : Persistent Memory
2400000000-43bfffffff : namespace2.0
WARNING: CPU: 38 PID: 928 at arch/x86/mm/init_64.c:850 add_pages+0x5c/0x60
[..]
RIP: 0010:add_pages+0x5c/0x60
[..]
Call Trace:
devm_memremap_pages+0x460/0x6e0
pmem_attach_disk+0x29e/0x680 [nd_pmem]
? nd_dax_probe+0xfc/0x120 [libnvdimm]
nvdimm_bus_probe+0x66/0x160 [libnvdimm]
It was discovered that the problem goes beyond RAM vs PMEM collisions as
some platform produce PMEM vs PMEM collisions within a given section.
The libnvdimm workaround for that case revealed that the libnvdimm
section-alignment-padding implementation has been broken for a long
while.
A fix for that long-standing breakage introduces as many problems as it
solves as it would require a backward-incompatible change to the
namespace metadata interpretation. Instead of that dubious route [1],
address the root problem in the memory-hotplug implementation.
Note that EEXIST is no longer treated as success as that is how
sparse_add_section() reports subsection collisions, it was also obviated
by recent changes to perform the request_region() for 'System RAM'
before arch_add_memory() in the add_memory() sequence.
[1] https://lore.kernel.org/r/155000671719.348031.2347363160141119237.stgit@dwillia2-desk3.amr.corp.intel.com
[osalvador@suse.de: fix deactivate_section for early sections]
Link: http://lkml.kernel.org/r/20190715081549.32577-2-osalvador@suse.de
Link: http://lkml.kernel.org/r/156092354368.979959.6232443923440952359.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [ppc64]
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Given there are no more usages of is_dev_zone() outside of 'ifdef
CONFIG_ZONE_DEVICE' protection, kill off the compilation helper.
Link: http://lkml.kernel.org/r/156092353211.979959.1489004866360828964.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Wei Yang <richardw.yang@linux.intel.com>
Acked-by: David Hildenbrand <david@redhat.com>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [ppc64]
Cc: Michal Hocko <mhocko@suse.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Prepare for hot{plug,remove} of sub-ranges of a section by tracking a
sub-section active bitmask, each bit representing a PMD_SIZE span of the
architecture's memory hotplug section size.
The implications of a partially populated section is that pfn_valid()
needs to go beyond a valid_section() check and either determine that the
section is an "early section", or read the sub-section active ranges
from the bitmask. The expectation is that the bitmask (subsection_map)
fits in the same cacheline as the valid_section() / early_section()
data, so the incremental performance overhead to pfn_valid() should be
negligible.
The rationale for using early_section() to short-ciruit the
subsection_map check is that there are legacy code paths that use
pfn_valid() at section granularity before validating the pfn against
pgdat data. So, the early_section() check allows those traditional
assumptions to persist while also permitting subsection_map to tell the
truth for purposes of populating the unused portions of early sections
with PMEM and other ZONE_DEVICE mappings.
Link: http://lkml.kernel.org/r/156092350874.979959.18185938451405518285.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Qian Cai <cai@lca.pw>
Tested-by: Jane Chu <jane.chu@oracle.com>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [ppc64]
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm: Sub-section memory hotplug support", v10.
The memory hotplug section is an arbitrary / convenient unit for memory
hotplug. 'Section-size' units have bled into the user interface
('memblock' sysfs) and can not be changed without breaking existing
userspace. The section-size constraint, while mostly benign for typical
memory hotplug, has and continues to wreak havoc with 'device-memory'
use cases, persistent memory (pmem) in particular. Recall that pmem
uses devm_memremap_pages(), and subsequently arch_add_memory(), to
allocate a 'struct page' memmap for pmem. However, it does not use the
'bottom half' of memory hotplug, i.e. never marks pmem pages online and
never exposes the userspace memblock interface for pmem. This leaves an
opening to redress the section-size constraint.
To date, the libnvdimm subsystem has attempted to inject padding to
satisfy the internal constraints of arch_add_memory(). Beyond
complicating the code, leading to bugs [2], wasting memory, and limiting
configuration flexibility, the padding hack is broken when the platform
changes this physical memory alignment of pmem from one boot to the
next. Device failure (intermittent or permanent) and physical
reconfiguration are events that can cause the platform firmware to
change the physical placement of pmem on a subsequent boot, and device
failure is an everyday event in a data-center.
It turns out that sections are only a hard requirement of the
user-facing interface for memory hotplug and with a bit more
infrastructure sub-section arch_add_memory() support can be added for
kernel internal usages like devm_memremap_pages(). Here is an analysis
of the current design assumptions in the current code and how they are
addressed in the new implementation:
Current design assumptions:
- Sections that describe boot memory (early sections) are never
unplugged / removed.
- pfn_valid(), in the CONFIG_SPARSEMEM_VMEMMAP=y, case devolves to a
valid_section() check
- __add_pages() and helper routines assume all operations occur in
PAGES_PER_SECTION units.
- The memblock sysfs interface only comprehends full sections
New design assumptions:
- Sections are instrumented with a sub-section bitmask to track (on
x86) individual 2MB sub-divisions of a 128MB section.
- Partially populated early sections can be extended with additional
sub-sections, and those sub-sections can be removed with
arch_remove_memory(). With this in place we no longer lose usable
memory capacity to padding.
- pfn_valid() is updated to look deeper than valid_section() to also
check the active-sub-section mask. This indication is in the same
cacheline as the valid_section() so the performance impact is
expected to be negligible. So far the lkp robot has not reported any
regressions.
- Outside of the core vmemmap population routines which are replaced,
other helper routines like shrink_{zone,pgdat}_span() are updated to
handle the smaller granularity. Core memory hotplug routines that
deal with online memory are not touched.
- The existing memblock sysfs user api guarantees / assumptions are not
touched since this capability is limited to !online
!memblock-sysfs-accessible sections.
Meanwhile the issue reports continue to roll in from users that do not
understand when and how the 128MB constraint will bite them. The current
implementation relied on being able to support at least one misaligned
namespace, but that immediately falls over on any moderately complex
namespace creation attempt. Beyond the initial problem of 'System RAM'
colliding with pmem, and the unsolvable problem of physical alignment
changes, Linux is now being exposed to platforms that collide pmem ranges
with other pmem ranges by default [3]. In short, devm_memremap_pages()
has pushed the venerable section-size constraint past the breaking point,
and the simplicity of section-aligned arch_add_memory() is no longer
tenable.
These patches are exposed to the kbuild robot on a subsection-v10 branch
[4], and a preview of the unit test for this functionality is available
on the 'subsection-pending' branch of ndctl [5].
[2]: https://lore.kernel.org/r/155000671719.348031.2347363160141119237.stgit@dwillia2-desk3.amr.corp.intel.com
[3]: https://github.com/pmem/ndctl/issues/76
[4]: https://git.kernel.org/pub/scm/linux/kernel/git/djbw/nvdimm.git/log/?h=subsection-v10
[5]: https://github.com/pmem/ndctl/commit/7c59b4867e1c
This patch (of 13):
Towards enabling memory hotplug to track partial population of a section,
introduce 'struct mem_section_usage'.
A pointer to a 'struct mem_section_usage' instance replaces the existing
pointer to a 'pageblock_flags' bitmap. Effectively it adds one more
'unsigned long' beyond the 'pageblock_flags' (usemap) allocation to house
a new 'subsection_map' bitmap. The new bitmap enables the memory
hot{plug,remove} implementation to act on incremental sub-divisions of a
section.
SUBSECTION_SHIFT is defined as global constant instead of per-architecture
value like SECTION_SIZE_BITS in order to allow cross-arch compatibility of
subsection users. Specifically a common subsection size allows for the
possibility that persistent memory namespace configurations be made
compatible across architectures.
The primary motivation for this functionality is to support platforms that
mix "System RAM" and "Persistent Memory" within a single section, or
multiple PMEM ranges with different mapping lifetimes within a single
section. The section restriction for hotplug has caused an ongoing saga
of hacks and bugs for devm_memremap_pages() users.
Beyond the fixups to teach existing paths how to retrieve the 'usemap'
from a section, and updates to usemap allocation path, there are no
expected behavior changes.
Link: http://lkml.kernel.org/r/156092349845.979959.73333291612799019.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Wei Yang <richardw.yang@linux.intel.com>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [ppc64]
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Qian Cai <cai@lca.pw>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm/vmscan: calculate reclaimed slab in all reclaim paths".
This patchset is to fix the issues in doing shrink slab.
There're six different reclaim paths by now,
- kswapd reclaim path
- node reclaim path
- hibernate preallocate memory reclaim path
- direct reclaim path
- memcg reclaim path
- memcg softlimit reclaim path
The slab caches reclaimed in these paths are only calculated in the
above three paths. The issues are detailed explained in patch #2. We
should calculate the reclaimed slab caches in every reclaim path. In
order to do it, the struct reclaim_state is placed into the struct
shrink_control.
In node reclaim path, there'is another issue about shrinking slab, which
is adressed in "mm/vmscan: shrink slab in node reclaim"
(https://lore.kernel.org/linux-mm/1559874946-22960-1-git-send-email-laoar.shao@gmail.com/).
This patch (of 2):
The struct reclaim_state is used to record how many slab caches are
reclaimed in one reclaim path. The struct shrink_control is used to
control one reclaim path. So we'd better put reclaim_state into
shrink_control.
[laoar.shao@gmail.com: remove reclaim_state assignment from __perform_reclaim()]
Link: http://lkml.kernel.org/r/1561381582-13697-1-git-send-email-laoar.shao@gmail.com
Link: http://lkml.kernel.org/r/1561112086-6169-2-git-send-email-laoar.shao@gmail.com
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Improvements and bug fixes for the hmm interface in the kernel:
- Improve clarity, locking and APIs related to the 'hmm mirror' feature
merged last cycle. In linux-next we now see AMDGPU and nouveau to be
using this API.
- Remove old or transitional hmm APIs. These are hold overs from the past
with no users, or APIs that existed only to manage cross tree conflicts.
There are still a few more of these cleanups that didn't make the merge
window cut off.
- Improve some core mm APIs:
* export alloc_pages_vma() for driver use
* refactor into devm_request_free_mem_region() to manage
DEVICE_PRIVATE resource reservations
* refactor duplicative driver code into the core dev_pagemap
struct
- Remove hmm wrappers of improved core mm APIs, instead have drivers use
the simplified API directly
- Remove DEVICE_PUBLIC
- Simplify the kconfig flow for the hmm users and core code
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Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma
Pull HMM updates from Jason Gunthorpe:
"Improvements and bug fixes for the hmm interface in the kernel:
- Improve clarity, locking and APIs related to the 'hmm mirror'
feature merged last cycle. In linux-next we now see AMDGPU and
nouveau to be using this API.
- Remove old or transitional hmm APIs. These are hold overs from the
past with no users, or APIs that existed only to manage cross tree
conflicts. There are still a few more of these cleanups that didn't
make the merge window cut off.
- Improve some core mm APIs:
- export alloc_pages_vma() for driver use
- refactor into devm_request_free_mem_region() to manage
DEVICE_PRIVATE resource reservations
- refactor duplicative driver code into the core dev_pagemap
struct
- Remove hmm wrappers of improved core mm APIs, instead have drivers
use the simplified API directly
- Remove DEVICE_PUBLIC
- Simplify the kconfig flow for the hmm users and core code"
* tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (42 commits)
mm: don't select MIGRATE_VMA_HELPER from HMM_MIRROR
mm: remove the HMM config option
mm: sort out the DEVICE_PRIVATE Kconfig mess
mm: simplify ZONE_DEVICE page private data
mm: remove hmm_devmem_add
mm: remove hmm_vma_alloc_locked_page
nouveau: use devm_memremap_pages directly
nouveau: use alloc_page_vma directly
PCI/P2PDMA: use the dev_pagemap internal refcount
device-dax: use the dev_pagemap internal refcount
memremap: provide an optional internal refcount in struct dev_pagemap
memremap: replace the altmap_valid field with a PGMAP_ALTMAP_VALID flag
memremap: remove the data field in struct dev_pagemap
memremap: add a migrate_to_ram method to struct dev_pagemap_ops
memremap: lift the devmap_enable manipulation into devm_memremap_pages
memremap: pass a struct dev_pagemap to ->kill and ->cleanup
memremap: move dev_pagemap callbacks into a separate structure
memremap: validate the pagemap type passed to devm_memremap_pages
mm: factor out a devm_request_free_mem_region helper
mm: export alloc_pages_vma
...
Patch series "add init_on_alloc/init_on_free boot options", v10.
Provide init_on_alloc and init_on_free boot options.
These are aimed at preventing possible information leaks and making the
control-flow bugs that depend on uninitialized values more deterministic.
Enabling either of the options guarantees that the memory returned by the
page allocator and SL[AU]B is initialized with zeroes. SLOB allocator
isn't supported at the moment, as its emulation of kmem caches complicates
handling of SLAB_TYPESAFE_BY_RCU caches correctly.
Enabling init_on_free also guarantees that pages and heap objects are
initialized right after they're freed, so it won't be possible to access
stale data by using a dangling pointer.
As suggested by Michal Hocko, right now we don't let the heap users to
disable initialization for certain allocations. There's not enough
evidence that doing so can speed up real-life cases, and introducing ways
to opt-out may result in things going out of control.
This patch (of 2):
The new options are needed to prevent possible information leaks and make
control-flow bugs that depend on uninitialized values more deterministic.
This is expected to be on-by-default on Android and Chrome OS. And it
gives the opportunity for anyone else to use it under distros too via the
boot args. (The init_on_free feature is regularly requested by folks
where memory forensics is included in their threat models.)
init_on_alloc=1 makes the kernel initialize newly allocated pages and heap
objects with zeroes. Initialization is done at allocation time at the
places where checks for __GFP_ZERO are performed.
init_on_free=1 makes the kernel initialize freed pages and heap objects
with zeroes upon their deletion. This helps to ensure sensitive data
doesn't leak via use-after-free accesses.
Both init_on_alloc=1 and init_on_free=1 guarantee that the allocator
returns zeroed memory. The two exceptions are slab caches with
constructors and SLAB_TYPESAFE_BY_RCU flag. Those are never
zero-initialized to preserve their semantics.
Both init_on_alloc and init_on_free default to zero, but those defaults
can be overridden with CONFIG_INIT_ON_ALLOC_DEFAULT_ON and
CONFIG_INIT_ON_FREE_DEFAULT_ON.
If either SLUB poisoning or page poisoning is enabled, those options take
precedence over init_on_alloc and init_on_free: initialization is only
applied to unpoisoned allocations.
Slowdown for the new features compared to init_on_free=0, init_on_alloc=0:
hackbench, init_on_free=1: +7.62% sys time (st.err 0.74%)
hackbench, init_on_alloc=1: +7.75% sys time (st.err 2.14%)
Linux build with -j12, init_on_free=1: +8.38% wall time (st.err 0.39%)
Linux build with -j12, init_on_free=1: +24.42% sys time (st.err 0.52%)
Linux build with -j12, init_on_alloc=1: -0.13% wall time (st.err 0.42%)
Linux build with -j12, init_on_alloc=1: +0.57% sys time (st.err 0.40%)
The slowdown for init_on_free=0, init_on_alloc=0 compared to the baseline
is within the standard error.
The new features are also going to pave the way for hardware memory
tagging (e.g. arm64's MTE), which will require both on_alloc and on_free
hooks to set the tags for heap objects. With MTE, tagging will have the
same cost as memory initialization.
Although init_on_free is rather costly, there are paranoid use-cases where
in-memory data lifetime is desired to be minimized. There are various
arguments for/against the realism of the associated threat models, but
given that we'll need the infrastructure for MTE anyway, and there are
people who want wipe-on-free behavior no matter what the performance cost,
it seems reasonable to include it in this series.
[glider@google.com: v8]
Link: http://lkml.kernel.org/r/20190626121943.131390-2-glider@google.com
[glider@google.com: v9]
Link: http://lkml.kernel.org/r/20190627130316.254309-2-glider@google.com
[glider@google.com: v10]
Link: http://lkml.kernel.org/r/20190628093131.199499-2-glider@google.com
Link: http://lkml.kernel.org/r/20190617151050.92663-2-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Michal Hocko <mhocko@suse.cz> [page and dmapool parts
Acked-by: James Morris <jamorris@linux.microsoft.com>]
Cc: Christoph Lameter <cl@linux.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Sandeep Patil <sspatil@android.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Jann Horn <jannh@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
CONFIG_NUMA on 64-bit CPUs currently enables hashdist unconditionally even
when booting on single node machines. This causes the large system hashes
to be allocated with vmalloc, and mapped with small pages.
This change clears hashdist if only one node has come up with memory.
This results in the important large inode and dentry hashes using memblock
allocations. All others are within 4MB size up to about 128GB of RAM,
which allows them to be allocated from the linear map on most non-NUMA
images.
Other big hashes like futex and TCP should eventually be moved over to the
same style of allocation as those vfs caches that use HASH_EARLY if
!hashdist, so they don't exceed MAX_ORDER on very large non-NUMA images.
This brings dTLB misses for linux kernel tree `git diff` from ~45,000 to
~8,000 on a Kaby Lake KVM guest with 8MB dentry hash and mitigations=off
(performance is in the noise, under 1% difference, page tables are likely
to be well cached for this workload).
Link: http://lkml.kernel.org/r/20190605144814.29319-2-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kernel currently clamps large system hashes to MAX_ORDER when hashdist
is not set, which is rather arbitrary.
vmalloc space is limited on 32-bit machines, but this shouldn't result in
much more used because of small physical memory limiting system hash
sizes.
Include "vmalloc" or "linear" in the kernel log message.
Link: http://lkml.kernel.org/r/20190605144814.29319-1-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When debug_pagealloc is enabled, we currently allocate the page_ext
array to mark guard pages with the PAGE_EXT_DEBUG_GUARD flag. Now that
we have the page_type field in struct page, we can use that instead, as
guard pages are neither PageSlab nor mapped to userspace. This reduces
memory overhead when debug_pagealloc is enabled and there are no other
features requiring the page_ext array.
Link: http://lkml.kernel.org/r/20190603143451.27353-4-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The page allocator checks struct pages for expected state (mapcount,
flags etc) as pages are being allocated (check_new_page()) and freed
(free_pages_check()) to provide some defense against errors in page
allocator users.
Prior commits 479f854a20 ("mm, page_alloc: defer debugging checks of
pages allocated from the PCP") and 4db7548ccb ("mm, page_alloc: defer
debugging checks of freed pages until a PCP drain") this has happened
for order-0 pages as they were allocated from or freed to the per-cpu
caches (pcplists). Since those are fast paths, the checks are now
performed only when pages are moved between pcplists and global free
lists. This however lowers the chances of catching errors soon enough.
In order to increase the chances of the checks to catch errors, the
kernel has to be rebuilt with CONFIG_DEBUG_VM, which also enables
multiple other internal debug checks (VM_BUG_ON() etc), which is
suboptimal when the goal is to catch errors in mm users, not in mm code
itself.
To catch some wrong users of the page allocator we have
CONFIG_DEBUG_PAGEALLOC, which is designed to have virtually no overhead
unless enabled at boot time. Memory corruptions when writing to freed
pages have often the same underlying errors (use-after-free, double free)
as corrupting the corresponding struct pages, so this existing debugging
functionality is a good fit to extend by also perform struct page checks
at least as often as if CONFIG_DEBUG_VM was enabled.
Specifically, after this patch, when debug_pagealloc is enabled on boot,
and CONFIG_DEBUG_VM disabled, pages are checked when allocated from or
freed to the pcplists *in addition* to being moved between pcplists and
free lists. When both debug_pagealloc and CONFIG_DEBUG_VM are enabled,
pages are checked when being moved between pcplists and free lists *in
addition* to when allocated from or freed to the pcplists.
When debug_pagealloc is not enabled on boot, the overhead in fast paths
should be virtually none thanks to the use of static key.
Link: http://lkml.kernel.org/r/20190603143451.27353-3-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "debug_pagealloc improvements".
I have been recently debugging some pcplist corruptions, where it would be
useful to perform struct page checks immediately as pages are allocated
from and freed to pcplists, which is now only possible by rebuilding the
kernel with CONFIG_DEBUG_VM (details in Patch 2 changelog).
To make this kind of debugging simpler in future on a distro kernel, I
have improved CONFIG_DEBUG_PAGEALLOC so that it has even smaller overhead
when not enabled at boot time (Patch 1) and also when enabled (Patch 3),
and extended it to perform the struct page checks more often when enabled
(Patch 2). Now it can be configured in when building a distro kernel
without extra overhead, and debugging page use after free or double free
can be enabled simply by rebooting with debug_pagealloc=on.
This patch (of 3):
CONFIG_DEBUG_PAGEALLOC has been redesigned by 031bc5743f
("mm/debug-pagealloc: make debug-pagealloc boottime configurable") to
allow being always enabled in a distro kernel, but only perform its
expensive functionality when booted with debug_pagelloc=on. We can
further reduce the overhead when not boot-enabled (including page
allocator fast paths) using static keys. This patch introduces one for
debug_pagealloc core functionality, and another for the optional guard
page functionality (enabled by booting with debug_guardpage_minorder=X).
Link: http://lkml.kernel.org/r/20190603143451.27353-2-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Previously totalram_pages was the global variable. Currently,
totalram_pages is the static inline function from the include/linux/mm.h
However, the function is also marked as EXPORT_SYMBOL, which is at best an
odd combination. Because there is no point for the static inline function
from a public header to be exported, this commit removes the
EXPORT_SYMBOL() marking. It will be still possible to use the function in
modules because all the symbols it depends on are exported.
Link: http://lkml.kernel.org/r/20190710141031.15642-1-efremov@linux.com
Fixes: ca79b0c211 ("mm: convert totalram_pages and totalhigh_pages variables to atomic")
Signed-off-by: Denis Efremov <efremov@linux.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 0e56acae4b ("mm: initialize MAX_ORDER_NR_PAGES at a time
instead of doing larger sections") is causing a regression on some
systems when the kernel is booted as Xen dom0.
The system will just hang in early boot.
Reason is an endless loop in get_page_from_freelist() in case the first
zone looked at has no free memory. deferred_grow_zone() is always
returning true due to the following code snipplet:
/* If the zone is empty somebody else may have cleared out the zone */
if (!deferred_init_mem_pfn_range_in_zone(&i, zone, &spfn, &epfn,
first_deferred_pfn)) {
pgdat->first_deferred_pfn = ULONG_MAX;
pgdat_resize_unlock(pgdat, &flags);
return true;
}
This in turn results in the loop as get_page_from_freelist() is assuming
forward progress can be made by doing some more struct page
initialization.
Link: http://lkml.kernel.org/r/20190620160821.4210-1-jgross@suse.com
Fixes: 0e56acae4b ("mm: initialize MAX_ORDER_NR_PAGES at a time instead of doing larger sections")
Signed-off-by: Juergen Gross <jgross@suse.com>
Suggested-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Acked-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove the clumsy hmm_devmem_page_{get,set}_drvdata helpers, and
instead just access the page directly. Also make the page data
a void pointer, and thus much easier to use.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Add a flags field to struct dev_pagemap to replace the altmap_valid
boolean to be a little more extensible. Also add a pgmap_altmap() helper
to find the optional altmap and clean up the code using the altmap using
it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Add SPDX license identifiers to all files which:
- Have no license information of any form
- Have EXPORT_.*_SYMBOL_GPL inside which was used in the
initial scan/conversion to ignore the file
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When freeing a page with an order >= shuffle_page_order randomly select
the front or back of the list for insertion.
While the mm tries to defragment physical pages into huge pages this can
tend to make the page allocator more predictable over time. Inject the
front-back randomness to preserve the initial randomness established by
shuffle_free_memory() when the kernel was booted.
The overhead of this manipulation is constrained by only being applied
for MAX_ORDER sized pages by default.
[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/154899812788.3165233.9066631950746578517.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Robert Elliott <elliott@hpe.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In preparation for runtime randomization of the zone lists, take all
(well, most of) the list_*() functions in the buddy allocator and put
them in helper functions. Provide a common control point for injecting
additional behavior when freeing pages.
[dan.j.williams@intel.com: fix buddy list helpers]
Link: http://lkml.kernel.org/r/155033679702.1773410.13041474192173212653.stgit@dwillia2-desk3.amr.corp.intel.com
[vbabka@suse.cz: remove del_page_from_free_area() migratetype parameter]
Link: http://lkml.kernel.org/r/4672701b-6775-6efd-0797-b6242591419e@suse.cz
Link: http://lkml.kernel.org/r/154899812264.3165233.5219320056406926223.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Robert Elliott <elliott@hpe.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm: Randomize free memory", v10.
This patch (of 3):
Randomization of the page allocator improves the average utilization of
a direct-mapped memory-side-cache. Memory side caching is a platform
capability that Linux has been previously exposed to in HPC
(high-performance computing) environments on specialty platforms. In
that instance it was a smaller pool of high-bandwidth-memory relative to
higher-capacity / lower-bandwidth DRAM. Now, this capability is going
to be found on general purpose server platforms where DRAM is a cache in
front of higher latency persistent memory [1].
Robert offered an explanation of the state of the art of Linux
interactions with memory-side-caches [2], and I copy it here:
It's been a problem in the HPC space:
http://www.nersc.gov/research-and-development/knl-cache-mode-performance-coe/
A kernel module called zonesort is available to try to help:
https://software.intel.com/en-us/articles/xeon-phi-software
and this abandoned patch series proposed that for the kernel:
https://lkml.kernel.org/r/20170823100205.17311-1-lukasz.daniluk@intel.com
Dan's patch series doesn't attempt to ensure buffers won't conflict, but
also reduces the chance that the buffers will. This will make performance
more consistent, albeit slower than "optimal" (which is near impossible
to attain in a general-purpose kernel). That's better than forcing
users to deploy remedies like:
"To eliminate this gradual degradation, we have added a Stream
measurement to the Node Health Check that follows each job;
nodes are rebooted whenever their measured memory bandwidth
falls below 300 GB/s."
A replacement for zonesort was merged upstream in commit cc9aec03e5
("x86/numa_emulation: Introduce uniform split capability"). With this
numa_emulation capability, memory can be split into cache sized
("near-memory" sized) numa nodes. A bind operation to such a node, and
disabling workloads on other nodes, enables full cache performance.
However, once the workload exceeds the cache size then cache conflicts
are unavoidable. While HPC environments might be able to tolerate
time-scheduling of cache sized workloads, for general purpose server
platforms, the oversubscribed cache case will be the common case.
The worst case scenario is that a server system owner benchmarks a
workload at boot with an un-contended cache only to see that performance
degrade over time, even below the average cache performance due to
excessive conflicts. Randomization clips the peaks and fills in the
valleys of cache utilization to yield steady average performance.
Here are some performance impact details of the patches:
1/ An Intel internal synthetic memory bandwidth measurement tool, saw a
3X speedup in a contrived case that tries to force cache conflicts.
The contrived cased used the numa_emulation capability to force an
instance of the benchmark to be run in two of the near-memory sized
numa nodes. If both instances were placed on the same emulated they
would fit and cause zero conflicts. While on separate emulated nodes
without randomization they underutilized the cache and conflicted
unnecessarily due to the in-order allocation per node.
2/ A well known Java server application benchmark was run with a heap
size that exceeded cache size by 3X. The cache conflict rate was 8%
for the first run and degraded to 21% after page allocator aging. With
randomization enabled the rate levelled out at 11%.
3/ A MongoDB workload did not observe measurable difference in
cache-conflict rates, but the overall throughput dropped by 7% with
randomization in one case.
4/ Mel Gorman ran his suite of performance workloads with randomization
enabled on platforms without a memory-side-cache and saw a mix of some
improvements and some losses [3].
While there is potentially significant improvement for applications that
depend on low latency access across a wide working-set, the performance
may be negligible to negative for other workloads. For this reason the
shuffle capability defaults to off unless a direct-mapped
memory-side-cache is detected. Even then, the page_alloc.shuffle=0
parameter can be specified to disable the randomization on those systems.
Outside of memory-side-cache utilization concerns there is potentially
security benefit from randomization. Some data exfiltration and
return-oriented-programming attacks rely on the ability to infer the
location of sensitive data objects. The kernel page allocator, especially
early in system boot, has predictable first-in-first out behavior for
physical pages. Pages are freed in physical address order when first
onlined.
Quoting Kees:
"While we already have a base-address randomization
(CONFIG_RANDOMIZE_MEMORY), attacks against the same hardware and
memory layouts would certainly be using the predictability of
allocation ordering (i.e. for attacks where the base address isn't
important: only the relative positions between allocated memory).
This is common in lots of heap-style attacks. They try to gain
control over ordering by spraying allocations, etc.
I'd really like to see this because it gives us something similar
to CONFIG_SLAB_FREELIST_RANDOM but for the page allocator."
While SLAB_FREELIST_RANDOM reduces the predictability of some local slab
caches it leaves vast bulk of memory to be predictably in order allocated.
However, it should be noted, the concrete security benefits are hard to
quantify, and no known CVE is mitigated by this randomization.
Introduce shuffle_free_memory(), and its helper shuffle_zone(), to perform
a Fisher-Yates shuffle of the page allocator 'free_area' lists when they
are initially populated with free memory at boot and at hotplug time. Do
this based on either the presence of a page_alloc.shuffle=Y command line
parameter, or autodetection of a memory-side-cache (to be added in a
follow-on patch).
The shuffling is done in terms of CONFIG_SHUFFLE_PAGE_ORDER sized free
pages where the default CONFIG_SHUFFLE_PAGE_ORDER is MAX_ORDER-1 i.e. 10,
4MB this trades off randomization granularity for time spent shuffling.
MAX_ORDER-1 was chosen to be minimally invasive to the page allocator
while still showing memory-side cache behavior improvements, and the
expectation that the security implications of finer granularity
randomization is mitigated by CONFIG_SLAB_FREELIST_RANDOM. The
performance impact of the shuffling appears to be in the noise compared to
other memory initialization work.
This initial randomization can be undone over time so a follow-on patch is
introduced to inject entropy on page free decisions. It is reasonable to
ask if the page free entropy is sufficient, but it is not enough due to
the in-order initial freeing of pages. At the start of that process
putting page1 in front or behind page0 still keeps them close together,
page2 is still near page1 and has a high chance of being adjacent. As
more pages are added ordering diversity improves, but there is still high
page locality for the low address pages and this leads to no significant
impact to the cache conflict rate.
[1]: https://itpeernetwork.intel.com/intel-optane-dc-persistent-memory-operating-modes/
[2]: https://lkml.kernel.org/r/AT5PR8401MB1169D656C8B5E121752FC0F8AB120@AT5PR8401MB1169.NAMPRD84.PROD.OUTLOOK.COM
[3]: https://lkml.org/lkml/2018/10/12/309
[dan.j.williams@intel.com: fix shuffle enable]
Link: http://lkml.kernel.org/r/154943713038.3858443.4125180191382062871.stgit@dwillia2-desk3.amr.corp.intel.com
[cai@lca.pw: fix SHUFFLE_PAGE_ALLOCATOR help texts]
Link: http://lkml.kernel.org/r/20190425201300.75650-1-cai@lca.pw
Link: http://lkml.kernel.org/r/154899811738.3165233.12325692939590944259.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Qian Cai <cai@lca.pw>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Robert Elliott <elliott@hpe.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 0139aa7b7f ("mm: rename _count, field of the struct page, to
_refcount") left out a couple of references to the old field name. Fix
that.
Link: http://lkml.kernel.org/r/cedf87b02eb8a6b3eac57e8e91da53fb15c3c44c.1556537475.git.baruch@tkos.co.il
Fixes: 0139aa7b7f ("mm: rename _count, field of the struct page, to _refcount")
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Most architectures do not need the memblock memory after the page
allocator is initialized, but only few enable ARCH_DISCARD_MEMBLOCK in the
arch Kconfig.
Replacing ARCH_DISCARD_MEMBLOCK with ARCH_KEEP_MEMBLOCK and inverting the
logic makes it clear which architectures actually use memblock after
system initialization and skips the necessity to add ARCH_DISCARD_MEMBLOCK
to the architectures that are still missing that option.
Link: http://lkml.kernel.org/r/1556102150-32517-1-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Because rmqueue_pcplist() is only called when order is 0, we don't need to
use order as a parameter.
Link: http://lkml.kernel.org/r/1555591709-11744-1-git-send-email-laoar.shao@gmail.com
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Pankaj Gupta <pagupta@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
check_pages_isolated_cb currently accounts the whole pfn range as being
offlined if test_pages_isolated suceeds on the range. This is based on
the assumption that all pages in the range are freed which is currently
the case in most cases but it won't be with later changes, as pages marked
as vmemmap won't be isolated.
Move the offlined pages counting to offline_isolated_pages_cb and rely on
__offline_isolated_pages to return the correct value.
check_pages_isolated_cb will still do it's primary job and check the pfn
range.
While we are at it remove check_pages_isolated and offline_isolated_pages
and use directly walk_system_ram_range as do in online_pages.
Link: http://lkml.kernel.org/r/20190408082633.2864-2-osalvador@suse.de
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add yet another iterator, for_each_free_mem_range_in_zone_from, and then
use it to support initializing and freeing pages in groups no larger than
MAX_ORDER_NR_PAGES. By doing this we can greatly improve the cache
locality of the pages while we do several loops over them in the init and
freeing process.
We are able to tighten the loops further as a result of the "from"
iterator as we can perform the initial checks for first_init_pfn in our
first call to the iterator, and continue without the need for those checks
via the "from" iterator. I have added this functionality in the function
called deferred_init_mem_pfn_range_in_zone that primes the iterator and
causes us to exit if we encounter any failure.
On my x86_64 test system with 384GB of memory per node I saw a reduction
in initialization time from 1.85s to 1.38s as a result of this patch.
Link: http://lkml.kernel.org/r/20190405221231.12227.85836.stgit@localhost.localdomain
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: <yi.z.zhang@linux.intel.com>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Introduce a new iterator for_each_free_mem_pfn_range_in_zone.
This iterator will take care of making sure a given memory range provided
is in fact contained within a zone. It takes are of all the bounds
checking we were doing in deferred_grow_zone, and deferred_init_memmap.
In addition it should help to speed up the search a bit by iterating until
the end of a range is greater than the start of the zone pfn range, and
will exit completely if the start is beyond the end of the zone.
Link: http://lkml.kernel.org/r/20190405221225.12227.22573.stgit@localhost.localdomain
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <yi.z.zhang@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As best as I can tell the meminit_pfn_in_nid call is completely redundant.
The deferred memory initialization is already making use of
for_each_free_mem_range which in turn will call into __next_mem_range
which will only return a memory range if it matches the node ID provided
assuming it is not NUMA_NO_NODE.
I am operating on the assumption that there are no zones or pgdata_t
structures that have a NUMA node of NUMA_NO_NODE associated with them. If
that is the case then __next_mem_range will never return a memory range
that doesn't match the zone's node ID and as such the check is redundant.
So one piece I would like to verify on this is if this works for ia64.
Technically it was using a different approach to get the node ID, but it
seems to have the node ID also encoded into the memblock. So I am
assuming this is okay, but would like to get confirmation on that.
On my x86_64 test system with 384GB of memory per node I saw a reduction
in initialization time from 2.80s to 1.85s as a result of this patch.
Link: http://lkml.kernel.org/r/20190405221219.12227.93957.stgit@localhost.localdomain
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Reviewed-by: Pavel Tatashin <pavel.tatashin@microsoft.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <yi.z.zhang@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
342332e6a9 ("mm/page_alloc.c: introduce kernelcore=mirror option") and
later patches rewrote the calculation of node spanned pages.
e506b99696 ("mem-hotplug: fix node spanned pages when we have a movable
node"), but the current code still has problems,
When we have a node with only zone_movable and the node id is not zero,
the size of node spanned pages is double added.
That's because we have an empty normal zone, and zone_start_pfn or
zone_end_pfn is not between arch_zone_lowest_possible_pfn and
arch_zone_highest_possible_pfn, so we need to use clamp to constrain the
range just like the commit <96e907d13602> (bootmem: Reimplement
__absent_pages_in_range() using for_each_mem_pfn_range()).
e.g.
Zone ranges:
DMA [mem 0x0000000000001000-0x0000000000ffffff]
DMA32 [mem 0x0000000001000000-0x00000000ffffffff]
Normal [mem 0x0000000100000000-0x000000023fffffff]
Movable zone start for each node
Node 0: 0x0000000100000000
Node 1: 0x0000000140000000
Early memory node ranges
node 0: [mem 0x0000000000001000-0x000000000009efff]
node 0: [mem 0x0000000000100000-0x00000000bffdffff]
node 0: [mem 0x0000000100000000-0x000000013fffffff]
node 1: [mem 0x0000000140000000-0x000000023fffffff]
node 0 DMA spanned:0xfff present:0xf9e absent:0x61
node 0 DMA32 spanned:0xff000 present:0xbefe0 absent:0x40020
node 0 Normal spanned:0 present:0 absent:0
node 0 Movable spanned:0x40000 present:0x40000 absent:0
On node 0 totalpages(node_present_pages): 1048446
node_spanned_pages:1310719
node 1 DMA spanned:0 present:0 absent:0
node 1 DMA32 spanned:0 present:0 absent:0
node 1 Normal spanned:0x100000 present:0x100000 absent:0
node 1 Movable spanned:0x100000 present:0x100000 absent:0
On node 1 totalpages(node_present_pages): 2097152
node_spanned_pages:2097152
Memory: 6967796K/12582392K available (16388K kernel code, 3686K rwdata,
4468K rodata, 2160K init, 10444K bss, 5614596K reserved, 0K
cma-reserved)
It shows that the current memory of node 1 is double added.
After this patch, the problem is fixed.
node 0 DMA spanned:0xfff present:0xf9e absent:0x61
node 0 DMA32 spanned:0xff000 present:0xbefe0 absent:0x40020
node 0 Normal spanned:0 present:0 absent:0
node 0 Movable spanned:0x40000 present:0x40000 absent:0
On node 0 totalpages(node_present_pages): 1048446
node_spanned_pages:1310719
node 1 DMA spanned:0 present:0 absent:0
node 1 DMA32 spanned:0 present:0 absent:0
node 1 Normal spanned:0 present:0 absent:0
node 1 Movable spanned:0x100000 present:0x100000 absent:0
On node 1 totalpages(node_present_pages): 1048576
node_spanned_pages:1048576
memory: 6967796K/8388088K available (16388K kernel code, 3686K rwdata,
4468K rodata, 2160K init, 10444K bss, 1420292K reserved, 0K
cma-reserved)
Link: http://lkml.kernel.org/r/1554178276-10372-1-git-send-email-fanglinxu@huawei.com
Signed-off-by: Linxu Fang <fanglinxu@huawei.com>
Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On systems without CONTIG_ALLOC activated but that support gigantic pages,
boottime reserved gigantic pages can not be freed at all. This patch
simply enables the possibility to hand back those pages to memory
allocator.
Link: http://lkml.kernel.org/r/20190327063626.18421-5-alex@ghiti.fr
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Acked-by: David S. Miller <davem@davemloft.net> [sparc]
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This condition allows to define alloc_contig_range, so simplify it into a
more accurate naming.
Link: http://lkml.kernel.org/r/20190327063626.18421-4-alex@ghiti.fr
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
alloc_pages_exact*() allocates a page of sufficient order and then splits
it to return only the number of pages requested. That makes it
incompatible with __GFP_COMP, because compound pages cannot be split.
As shown by [1] things may silently work until the requested size
(possibly depending on user) stops being power of two. Then for
CONFIG_DEBUG_VM, BUG_ON() triggers in split_page(). Without
CONFIG_DEBUG_VM, consequences are unclear.
There are several options here, none of them great:
1) Don't do the splitting when __GFP_COMP is passed, and return the
whole compound page. However if caller then returns it via
free_pages_exact(), that will be unexpected and the freeing actions
there will be wrong.
2) Warn and remove __GFP_COMP from the flags. But the caller may have
really wanted it, so things may break later somewhere.
3) Warn and return NULL. However NULL may be unexpected, especially
for small sizes.
This patch picks option 2, because as Michal Hocko put it: "callers wanted
it" is much less probable than "caller is simply confused and more gfp
flags is surely better than fewer".
[1] https://lore.kernel.org/lkml/20181126002805.GI18977@shao2-debian/T/#u
Link: http://lkml.kernel.org/r/0c6393eb-b28d-4607-c386-862a71f09de6@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make hibernate handle unmapped pages on the direct map when
CONFIG_ARCH_HAS_SET_ALIAS=y is set. These functions allow for setting pages
to invalid configurations, so now hibernate should check if the pages have
valid mappings and handle if they are unmapped when doing a hibernate
save operation.
Previously this checking was already done when CONFIG_DEBUG_PAGEALLOC=y
was configured. It does not appear to have a big hibernating performance
impact. The speed of the saving operation before this change was measured
as 819.02 MB/s, and after was measured at 813.32 MB/s.
Before:
[ 4.670938] PM: Wrote 171996 kbytes in 0.21 seconds (819.02 MB/s)
After:
[ 4.504714] PM: Wrote 178932 kbytes in 0.22 seconds (813.32 MB/s)
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: <akpm@linux-foundation.org>
Cc: <ard.biesheuvel@linaro.org>
Cc: <deneen.t.dock@intel.com>
Cc: <kernel-hardening@lists.openwall.com>
Cc: <kristen@linux.intel.com>
Cc: <linux_dti@icloud.com>
Cc: <will.deacon@arm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190426001143.4983-16-namit@vmware.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit 0a79cdad5e ("mm: use alloc_flags to record if kswapd can wake")
removed setting of the ALLOC_NOFRAGMENT flag. Bring it back.
The runtime effect is that ALLOC_NOFRAGMENT behaviour is restored so
that allocations are spread across local zones to avoid fragmentation
due to mixing pageblocks as long as possible.
Link: http://lkml.kernel.org/r/20190423120806.3503-2-aryabinin@virtuozzo.com
Fixes: 0a79cdad5e ("mm: use alloc_flags to record if kswapd can wake")
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ac.preferred_zoneref->zone passed to alloc_flags_nofragment() can be NULL.
'zone' pointer unconditionally derefernced in alloc_flags_nofragment().
Bail out on NULL zone to avoid potential crash. Currently we don't see
any crashes only because alloc_flags_nofragment() has another bug which
allows compiler to optimize away all accesses to 'zone'.
Link: http://lkml.kernel.org/r/20190423120806.3503-1-aryabinin@virtuozzo.com
Fixes: 6bb154504f ("mm, page_alloc: spread allocations across zones before introducing fragmentation")
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
During the development of commit 5e1f0f098b ("mm, compaction: capture
a page under direct compaction"), a paranoid check was added to ensure
that if a captured page was available after compaction that it was
consistent with the final state of compaction. The intent was to catch
serious programming bugs such as using a stale page pointer and causing
corruption problems.
However, it is possible to get a captured page even if compaction was
unsuccessful if an interrupt triggered and happened to free pages in
interrupt context that got merged into a suitable high-order page. It's
highly unlikely but Li Wang did report the following warning on s390
occuring when testing OOM handling. Note that the warning is slightly
edited for clarity.
WARNING: CPU: 0 PID: 9783 at mm/page_alloc.c:3777 __alloc_pages_direct_compact+0x182/0x190
Modules linked in: rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs
lockd grace fscache sunrpc pkey ghash_s390 prng xts aes_s390
des_s390 des_generic sha512_s390 zcrypt_cex4 zcrypt vmur binfmt_misc
ip_tables xfs libcrc32c dasd_fba_mod qeth_l2 dasd_eckd_mod dasd_mod
qeth qdio lcs ctcm ccwgroup fsm dm_mirror dm_region_hash dm_log
dm_mod
CPU: 0 PID: 9783 Comm: copy.sh Kdump: loaded Not tainted 5.1.0-rc 5 #1
This patch simply removes the check entirely instead of trying to be
clever about pages freed from interrupt context. If a serious
programming error was introduced, it is highly likely to be caught by
prep_new_page() instead.
Link: http://lkml.kernel.org/r/20190419085133.GH18914@techsingularity.net
Fixes: 5e1f0f098b ("mm, compaction: capture a page under direct compaction")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reported-by: Li Wang <liwang@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mikulas Patocka reported that commit 1c30844d2d ("mm: reclaim small
amounts of memory when an external fragmentation event occurs") "broke"
memory management on parisc.
The machine is not NUMA but the DISCONTIG model creates three pgdats
even though it's a UMA machine for the following ranges
0) Start 0x0000000000000000 End 0x000000003fffffff Size 1024 MB
1) Start 0x0000000100000000 End 0x00000001bfdfffff Size 3070 MB
2) Start 0x0000004040000000 End 0x00000040ffffffff Size 3072 MB
Mikulas reported:
With the patch 1c30844d2, the kernel will incorrectly reclaim the
first zone when it fills up, ignoring the fact that there are two
completely free zones. Basiscally, it limits cache size to 1GiB.
For example, if I run:
# dd if=/dev/sda of=/dev/null bs=1M count=2048
- with the proper kernel, there should be "Buffers - 2GiB"
when this command finishes. With the patch 1c30844d2, buffers
will consume just 1GiB or slightly more, because the kernel was
incorrectly reclaiming them.
The page allocator and reclaim makes assumptions that pgdats really
represent NUMA nodes and zones represent ranges and makes decisions on
that basis. Watermark boosting for small pgdats leads to unexpected
results even though this would have behaved reasonably on SPARSEMEM.
DISCONTIG is essentially deprecated and even parisc plans to move to
SPARSEMEM so there is no need to be fancy, this patch simply disables
watermark boosting by default on DISCONTIGMEM.
Link: http://lkml.kernel.org/r/20190419094335.GJ18914@techsingularity.net
Fixes: 1c30844d2d ("mm: reclaim small amounts of memory when an external fragmentation event occurs")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Tested-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: James Bottomley <James.Bottomley@hansenpartnership.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
has_unmovable_pages() is used by allocating CMA and gigantic pages as
well as the memory hotplug. The later doesn't know how to offline CMA
pool properly now, but if an unused (free) CMA page is encountered, then
has_unmovable_pages() happily considers it as a free memory and
propagates this up the call chain. Memory offlining code then frees the
page without a proper CMA tear down which leads to an accounting issues.
Moreover if the same memory range is onlined again then the memory never
gets back to the CMA pool.
State after memory offline:
# grep cma /proc/vmstat
nr_free_cma 205824
# cat /sys/kernel/debug/cma/cma-kvm_cma/count
209920
Also, kmemleak still think those memory address are reserved below but
have already been used by the buddy allocator after onlining. This
patch fixes the situation by treating CMA pageblocks as unmovable except
when has_unmovable_pages() is called as part of CMA allocation.
Offlined Pages 4096
kmemleak: Cannot insert 0xc000201f7d040008 into the object search tree (overlaps existing)
Call Trace:
dump_stack+0xb0/0xf4 (unreliable)
create_object+0x344/0x380
__kmalloc_node+0x3ec/0x860
kvmalloc_node+0x58/0x110
seq_read+0x41c/0x620
__vfs_read+0x3c/0x70
vfs_read+0xbc/0x1a0
ksys_read+0x7c/0x140
system_call+0x5c/0x70
kmemleak: Kernel memory leak detector disabled
kmemleak: Object 0xc000201cc8000000 (size 13757317120):
kmemleak: comm "swapper/0", pid 0, jiffies 4294937297
kmemleak: min_count = -1
kmemleak: count = 0
kmemleak: flags = 0x5
kmemleak: checksum = 0
kmemleak: backtrace:
cma_declare_contiguous+0x2a4/0x3b0
kvm_cma_reserve+0x11c/0x134
setup_arch+0x300/0x3f8
start_kernel+0x9c/0x6e8
start_here_common+0x1c/0x4b0
kmemleak: Automatic memory scanning thread ended
[cai@lca.pw: use is_migrate_cma_page() and update commit log]
Link: http://lkml.kernel.org/r/20190416170510.20048-1-cai@lca.pw
Link: http://lkml.kernel.org/r/20190413002623.8967-1-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit f1dd2cd13c ("mm, memory_hotplug: do not associate hotadded
memory to zones until online") introduced move_pfn_range_to_zone() which
calls memmap_init_zone() during onlining a memory block.
memmap_init_zone() will reset pagetype flags and makes migrate type to
be MOVABLE.
However, in __offline_pages(), it also call undo_isolate_page_range()
after offline_isolated_pages() to do the same thing. Due to commit
2ce13640b3 ("mm: __first_valid_page skip over offline pages") changed
__first_valid_page() to skip offline pages, undo_isolate_page_range()
here just waste CPU cycles looping around the offlining PFN range while
doing nothing, because __first_valid_page() will return NULL as
offline_isolated_pages() has already marked all memory sections within
the pfn range as offline via offline_mem_sections().
Also, after calling the "useless" undo_isolate_page_range() here, it
reaches the point of no returning by notifying MEM_OFFLINE. Those pages
will be marked as MIGRATE_MOVABLE again once onlining. The only thing
left to do is to decrease the number of isolated pageblocks zone counter
which would make some paths of the page allocation slower that the above
commit introduced.
Even if alloc_contig_range() can be used to isolate 16GB-hugetlb pages
on ppc64, an "int" should still be enough to represent the number of
pageblocks there. Fix an incorrect comment along the way.
[cai@lca.pw: v4]
Link: http://lkml.kernel.org/r/20190314150641.59358-1-cai@lca.pw
Link: http://lkml.kernel.org/r/20190313143133.46200-1-cai@lca.pw
Fixes: 2ce13640b3 ("mm: __first_valid_page skip over offline pages")
Signed-off-by: Qian Cai <cai@lca.pw>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org> [4.13+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As all the memblock allocation functions return NULL in case of error
rather than panic(), the duplicates with _nopanic suffix can be removed.
Link: http://lkml.kernel.org/r/1548057848-15136-22-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Petr Mladek <pmladek@suse.com> [printk]
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Guo Ren <ren_guo@c-sky.com> [c-sky]
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Juergen Gross <jgross@suse.com> [Xen]
Cc: Mark Salter <msalter@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This function is only used by built-in code, which makes perfect sense
given the purpose of it.
Link: http://lkml.kernel.org/r/20190213174621.29297-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Many kernel-doc comments in mm/ have the return value descriptions
either misformatted or omitted at all which makes kernel-doc script
unhappy:
$ make V=1 htmldocs
...
./mm/util.c:36: info: Scanning doc for kstrdup
./mm/util.c:41: warning: No description found for return value of 'kstrdup'
./mm/util.c:57: info: Scanning doc for kstrdup_const
./mm/util.c:66: warning: No description found for return value of 'kstrdup_const'
./mm/util.c:75: info: Scanning doc for kstrndup
./mm/util.c:83: warning: No description found for return value of 'kstrndup'
...
Fixing the formatting and adding the missing return value descriptions
eliminates ~100 such warnings.
Link: http://lkml.kernel.org/r/1549549644-4903-4-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Number of online NUMA nodes can't be negative as well. This doesn't
save space as the variable is used only in 32-bit context, but do it
anyway for consistency.
Link: http://lkml.kernel.org/r/20190201223151.GB15820@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are two early memory allocations that use
memblock_alloc_node_nopanic() and do not check its return value.
While this happens very early during boot and chances that the
allocation will fail are diminishing, it is still worth to have proper
checks for the allocation errors.
Link: http://lkml.kernel.org/r/1547734941-944-1-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
No functional change.
Link: http://lkml.kernel.org/r/20190118235123.27843-1-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code logic should
never do something different based on this.
Link: http://lkml.kernel.org/r/20190122152151.16139-14-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Laura Abbott <labbott@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Compaction is inherently race-prone as a suitable page freed during
compaction can be allocated by any parallel task. This patch uses a
capture_control structure to isolate a page immediately when it is freed
by a direct compactor in the slow path of the page allocator. The
intent is to avoid redundant scanning.
5.0.0-rc1 5.0.0-rc1
selective-v3r17 capture-v3r19
Amean fault-both-1 0.00 ( 0.00%) 0.00 * 0.00%*
Amean fault-both-3 2582.11 ( 0.00%) 2563.68 ( 0.71%)
Amean fault-both-5 4500.26 ( 0.00%) 4233.52 ( 5.93%)
Amean fault-both-7 5819.53 ( 0.00%) 6333.65 ( -8.83%)
Amean fault-both-12 9321.18 ( 0.00%) 9759.38 ( -4.70%)
Amean fault-both-18 9782.76 ( 0.00%) 10338.76 ( -5.68%)
Amean fault-both-24 15272.81 ( 0.00%) 13379.55 * 12.40%*
Amean fault-both-30 15121.34 ( 0.00%) 16158.25 ( -6.86%)
Amean fault-both-32 18466.67 ( 0.00%) 18971.21 ( -2.73%)
Latency is only moderately affected but the devil is in the details. A
closer examination indicates that base page fault latency is reduced but
latency of huge pages is increased as it takes creater care to succeed.
Part of the "problem" is that allocation success rates are close to 100%
even when under pressure and compaction gets harder
5.0.0-rc1 5.0.0-rc1
selective-v3r17 capture-v3r19
Percentage huge-3 96.70 ( 0.00%) 98.23 ( 1.58%)
Percentage huge-5 96.99 ( 0.00%) 95.30 ( -1.75%)
Percentage huge-7 94.19 ( 0.00%) 97.24 ( 3.24%)
Percentage huge-12 94.95 ( 0.00%) 97.35 ( 2.53%)
Percentage huge-18 96.74 ( 0.00%) 97.30 ( 0.58%)
Percentage huge-24 97.07 ( 0.00%) 97.55 ( 0.50%)
Percentage huge-30 95.69 ( 0.00%) 98.50 ( 2.95%)
Percentage huge-32 96.70 ( 0.00%) 99.27 ( 2.65%)
And scan rates are reduced as expected by 6% for the migration scanner
and 29% for the free scanner indicating that there is less redundant
work.
Compaction migrate scanned 20815362 19573286
Compaction free scanned 16352612 11510663
[mgorman@techsingularity.net: remove redundant check]
Link: http://lkml.kernel.org/r/20190201143853.GH9565@techsingularity.net
Link: http://lkml.kernel.org/r/20190118175136.31341-23-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When pageblocks get fragmented, watermarks are artifically boosted to
reclaim pages to avoid further fragmentation events. However,
compaction is often either fragmentation-neutral or moving movable pages
away from unmovable/reclaimable pages. As the true watermarks are
preserved, allow compaction to ignore the boost factor.
The expected impact is very slight as the main benefit is that
compaction is slightly more likely to succeed when the system has been
fragmented very recently. On both 1-socket and 2-socket machines for
THP-intensive allocation during fragmentation the success rate was
increased by less than 1% which is marginal. However, detailed tracing
indicated that failure of migration due to a premature ENOMEM triggered
by watermark checks were eliminated.
Link: http://lkml.kernel.org/r/20190118175136.31341-9-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In the current implementation, there are two places to isolate a range
of page: __offline_pages() and alloc_contig_range(). During this
procedure, it will drain pages on pcp list.
Below is a brief call flow:
__offline_pages()/alloc_contig_range()
start_isolate_page_range()
set_migratetype_isolate()
drain_all_pages()
drain_all_pages() <--- A
This snippet shows the current logic is isolate and drain pcp list for
each pageblock and drain pcp list again for the whole range.
start_isolate_page_range is responsible for isolating the given pfn
range. One part of that job is to make sure that also pages that are on
the allocator pcp lists are properly isolated. Otherwise they could be
reused and the range wouldn't be completely isolated until the memory is
freed back. While there is no strict guarantee here because pages might
get allocated at any time before drain_all_pages is called there doesn't
seem to be any strong demand for such a guarantee.
In any case, draining is already done at the isolation level and there
is no need to do it again later by start_isolate_page_range callers
(memory hotplug and CMA allocator currently). Therefore remove
pointless draining in existing callers to make the code more clear and
functionally correct.
[mhocko@suse.com: provide a clearer changelog for the last two paragraphs]
Link: http://lkml.kernel.org/r/20190105233141.2329-1-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move the memcg_kmem_enabled() checks into memcg kmem charge/uncharge
functions, so, the users don't have to explicitly check that condition.
This is purely code cleanup patch without any functional change. Only
the order of checks in memcg_charge_slab() can potentially be changed
but the functionally it will be same. This should not matter as
memcg_charge_slab() is not in the hot path.
Link: http://lkml.kernel.org/r/20190103161203.162375-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "Replace all open encodings for NUMA_NO_NODE", v3.
All these places for replacement were found by running the following
grep patterns on the entire kernel code. Please let me know if this
might have missed some instances. This might also have replaced some
false positives. I will appreciate suggestions, inputs and review.
1. git grep "nid == -1"
2. git grep "node == -1"
3. git grep "nid = -1"
4. git grep "node = -1"
This patch (of 2):
At present there are multiple places where invalid node number is
encoded as -1. Even though implicitly understood it is always better to
have macros in there. Replace these open encodings for an invalid node
number with the global macro NUMA_NO_NODE. This helps remove NUMA
related assumptions like 'invalid node' from various places redirecting
them to a common definition.
Link: http://lkml.kernel.org/r/1545127933-10711-2-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> [ixgbe]
Acked-by: Jens Axboe <axboe@kernel.dk> [mtip32xx]
Acked-by: Vinod Koul <vkoul@kernel.org> [dmaengine.c]
Acked-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc]
Acked-by: Doug Ledford <dledford@redhat.com> [drivers/infiniband]
Cc: Joseph Qi <jiangqi903@gmail.com>
Cc: Hans Verkuil <hverkuil@xs4all.nl>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When freeing pages are done with higher order, time spent on coalescing
pages by buddy allocator can be reduced. With section size of 256MB,
hot add latency of a single section shows improvement from 50-60 ms to
less than 1 ms, hence improving the hot add latency by 60 times. Modify
external providers of online callback to align with the change.
[arunks@codeaurora.org: v11]
Link: http://lkml.kernel.org/r/1547792588-18032-1-git-send-email-arunks@codeaurora.org
[akpm@linux-foundation.org: remove unused local, per Arun]
[akpm@linux-foundation.org: avoid return of void-returning __free_pages_core(), per Oscar]
[akpm@linux-foundation.org: fix it for mm-convert-totalram_pages-and-totalhigh_pages-variables-to-atomic.patch]
[arunks@codeaurora.org: v8]
Link: http://lkml.kernel.org/r/1547032395-24582-1-git-send-email-arunks@codeaurora.org
[arunks@codeaurora.org: v9]
Link: http://lkml.kernel.org/r/1547098543-26452-1-git-send-email-arunks@codeaurora.org
Link: http://lkml.kernel.org/r/1538727006-5727-1-git-send-email-arunks@codeaurora.org
Signed-off-by: Arun KS <arunks@codeaurora.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: Srivatsa Vaddagiri <vatsa@codeaurora.org>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
KASAN does not play well with the page poisoning (CONFIG_PAGE_POISONING).
It triggers false positives in the allocation path:
BUG: KASAN: use-after-free in memchr_inv+0x2ea/0x330
Read of size 8 at addr ffff88881f800000 by task swapper/0
CPU: 0 PID: 0 Comm: swapper Not tainted 5.0.0-rc1+ #54
Call Trace:
dump_stack+0xe0/0x19a
print_address_description.cold.2+0x9/0x28b
kasan_report.cold.3+0x7a/0xb5
__asan_report_load8_noabort+0x19/0x20
memchr_inv+0x2ea/0x330
kernel_poison_pages+0x103/0x3d5
get_page_from_freelist+0x15e7/0x4d90
because KASAN has not yet unpoisoned the shadow page for allocation
before it checks memchr_inv() but only found a stale poison pattern.
Also, false positives in free path,
BUG: KASAN: slab-out-of-bounds in kernel_poison_pages+0x29e/0x3d5
Write of size 4096 at addr ffff8888112cc000 by task swapper/0/1
CPU: 5 PID: 1 Comm: swapper/0 Not tainted 5.0.0-rc1+ #55
Call Trace:
dump_stack+0xe0/0x19a
print_address_description.cold.2+0x9/0x28b
kasan_report.cold.3+0x7a/0xb5
check_memory_region+0x22d/0x250
memset+0x28/0x40
kernel_poison_pages+0x29e/0x3d5
__free_pages_ok+0x75f/0x13e0
due to KASAN adds poisoned redzones around slab objects, but the page
poisoning needs to poison the whole page.
Link: http://lkml.kernel.org/r/20190114233405.67843-1-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Yury Norov reported that an arm64 KVM instance could not boot since
after v5.0-rc1 and could addressed by reverting the patches
1c30844d2d ("mm: reclaim small amounts of memory when an external
73444bc4d8 ("mm, page_alloc: do not wake kswapd with zone lock held")
The problem is that a division by zero error is possible if boosting
occurs very early in boot if the system has very little memory. This
patch avoids the division by zero error.
Link: http://lkml.kernel.org/r/20190213143012.GT9565@techsingularity.net
Fixes: 1c30844d2d ("mm: reclaim small amounts of memory when an external fragmentation event occurs")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reported-by: Yury Norov <yury.norov@gmail.com>
Tested-by: Yury Norov <yury.norov@gmail.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch replaces the size + 1 value introduced with the recent fix for 1
byte allocs with a constant value.
The idea here is to reduce code overhead as the previous logic would have
to read size into a register, then increment it, and write it back to
whatever field was being used. By using a constant we can avoid those
memory reads and arithmetic operations in favor of just encoding the
maximum value into the operation itself.
Fixes: 2c2ade8174 ("mm: page_alloc: fix ref bias in page_frag_alloc() for 1-byte allocs")
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The basic idea behind ->pagecnt_bias is: If we pre-allocate the maximum
number of references that we might need to create in the fastpath later,
the bump-allocation fastpath only has to modify the non-atomic bias value
that tracks the number of extra references we hold instead of the atomic
refcount. The maximum number of allocations we can serve (under the
assumption that no allocation is made with size 0) is nc->size, so that's
the bias used.
However, even when all memory in the allocation has been given away, a
reference to the page is still held; and in the `offset < 0` slowpath, the
page may be reused if everyone else has dropped their references.
This means that the necessary number of references is actually
`nc->size+1`.
Luckily, from a quick grep, it looks like the only path that can call
page_frag_alloc(fragsz=1) is TAP with the IFF_NAPI_FRAGS flag, which
requires CAP_NET_ADMIN in the init namespace and is only intended to be
used for kernel testing and fuzzing.
To test for this issue, put a `WARN_ON(page_ref_count(page) == 0)` in the
`offset < 0` path, below the virt_to_page() call, and then repeatedly call
writev() on a TAP device with IFF_TAP|IFF_NO_PI|IFF_NAPI_FRAGS|IFF_NAPI,
with a vector consisting of 15 elements containing 1 byte each.
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This reverts commit 2830bf6f05.
The underlying assumption that one sparse section belongs into a single
numa node doesn't hold really. Robert Shteynfeld has reported a boot
failure. The boot log was not captured but his memory layout is as
follows:
Early memory node ranges
node 1: [mem 0x0000000000001000-0x0000000000090fff]
node 1: [mem 0x0000000000100000-0x00000000dbdf8fff]
node 1: [mem 0x0000000100000000-0x0000001423ffffff]
node 0: [mem 0x0000001424000000-0x0000002023ffffff]
This means that node0 starts in the middle of a memory section which is
also in node1. memmap_init_zone tries to initialize padding of a
section even when it is outside of the given pfn range because there are
code paths (e.g. memory hotplug) which assume that the full worth of
memory section is always initialized.
In this particular case, though, such a range is already intialized and
most likely already managed by the page allocator. Scribbling over
those pages corrupts the internal state and likely blows up when any of
those pages gets used.
Reported-by: Robert Shteynfeld <robert.shteynfeld@gmail.com>
Fixes: 2830bf6f05 ("mm, memory_hotplug: initialize struct pages for the full memory section")
Cc: stable@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
syzbot reported the following regression in the latest merge window and
it was confirmed by Qian Cai that a similar bug was visible from a
different context.
======================================================
WARNING: possible circular locking dependency detected
4.20.0+ #297 Not tainted
------------------------------------------------------
syz-executor0/8529 is trying to acquire lock:
000000005e7fb829 (&pgdat->kswapd_wait){....}, at:
__wake_up_common_lock+0x19e/0x330 kernel/sched/wait.c:120
but task is already holding lock:
000000009bb7bae0 (&(&zone->lock)->rlock){-.-.}, at: spin_lock
include/linux/spinlock.h:329 [inline]
000000009bb7bae0 (&(&zone->lock)->rlock){-.-.}, at: rmqueue_bulk
mm/page_alloc.c:2548 [inline]
000000009bb7bae0 (&(&zone->lock)->rlock){-.-.}, at: __rmqueue_pcplist
mm/page_alloc.c:3021 [inline]
000000009bb7bae0 (&(&zone->lock)->rlock){-.-.}, at: rmqueue_pcplist
mm/page_alloc.c:3050 [inline]
000000009bb7bae0 (&(&zone->lock)->rlock){-.-.}, at: rmqueue
mm/page_alloc.c:3072 [inline]
000000009bb7bae0 (&(&zone->lock)->rlock){-.-.}, at:
get_page_from_freelist+0x1bae/0x52a0 mm/page_alloc.c:3491
It appears to be a false positive in that the only way the lock ordering
should be inverted is if kswapd is waking itself and the wakeup
allocates debugging objects which should already be allocated if it's
kswapd doing the waking. Nevertheless, the possibility exists and so
it's best to avoid the problem.
This patch flags a zone as needing a kswapd using the, surprisingly,
unused zone flag field. The flag is read without the lock held to do
the wakeup. It's possible that the flag setting context is not the same
as the flag clearing context or for small races to occur. However, each
race possibility is harmless and there is no visible degredation in
fragmentation treatment.
While zone->flag could have continued to be unused, there is potential
for moving some existing fields into the flags field instead.
Particularly read-mostly ones like zone->initialized and
zone->contiguous.
Link: http://lkml.kernel.org/r/20190103225712.GJ31517@techsingularity.net
Fixes: 1c30844d2d ("mm: reclaim small amounts of memory when an external fragmentation event occurs")
Reported-by: syzbot+93d94a001cfbce9e60e1@syzkaller.appspotmail.com
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Qian Cai <cai@lca.pw>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Model call chain after should_failslab(). Likewise, we can now use a
kprobe to override the return value of should_fail_alloc_page() and inject
allocation failures into alloc_page*().
This will allow injecting allocation failures using the BCC tools even
without building kernel with CONFIG_FAIL_PAGE_ALLOC and booting it with a
fail_page_alloc= parameter, which incurs some overhead even when failures
are not being injected. On the other hand, this patch adds an
unconditional call to should_fail_alloc_page() from page allocation
hotpath. That overhead should be rather negligible with
CONFIG_FAIL_PAGE_ALLOC=n when there's no kprobe attached, though.
[vbabka@suse.cz: changelog addition]
Link: http://lkml.kernel.org/r/20181214074330.18917-1-bpoirier@suse.com
Signed-off-by: Benjamin Poirier <bpoirier@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drain_all_pages is documented to drain per-cpu pages for a given zone (if
non-NULL). The current implementation doesn't match the description
though. It will drain all pcp pages for all zones that happen to have
cached pages on the same cpu as the given zone. This will lead to
premature pcp cache draining for zones that are not of any interest to the
caller - e.g. compaction, hwpoison or memory offline.
This forces the page allocator to take locks and potential lock contention
as a result.
There is no real reason for this sub-optimal implementation. Replace
per-cpu work item with a dedicated structure which contains a pointer to
the zone and pass it over to the worker. This will get the zone
information all the way down to the worker function and do the right job.
[akpm@linux-foundation.org: avoid 80-col tricks]
[mhocko@suse.com: refactor the whole changelog]
Link: http://lkml.kernel.org/r/20181212142550.61686-1-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When CONFIG_KASAN is enabled on large memory SMP systems, the deferrred
pages initialization can take a long time. Below were the reported init
times on a 8-socket 96-core 4TB IvyBridge system.
1) Non-debug kernel without CONFIG_KASAN
[ 8.764222] node 1 initialised, 132086516 pages in 7027ms
2) Debug kernel with CONFIG_KASAN
[ 146.288115] node 1 initialised, 132075466 pages in 143052ms
So the page init time in a debug kernel was 20X of the non-debug kernel.
The long init time can be problematic as the page initialization is done
with interrupt disabled. In this particular case, it caused the
appearance of following warning messages as well as NMI backtraces of all
the cores that were doing the initialization.
[ 68.240049] rcu: INFO: rcu_sched detected stalls on CPUs/tasks:
[ 68.241000] rcu: 25-...0: (100 ticks this GP) idle=b72/1/0x4000000000000000 softirq=915/915 fqs=16252
[ 68.241000] rcu: 44-...0: (95 ticks this GP) idle=49a/1/0x4000000000000000 softirq=788/788 fqs=16253
[ 68.241000] rcu: 54-...0: (104 ticks this GP) idle=03a/1/0x4000000000000000 softirq=721/825 fqs=16253
[ 68.241000] rcu: 60-...0: (103 ticks this GP) idle=cbe/1/0x4000000000000000 softirq=637/740 fqs=16253
[ 68.241000] rcu: 72-...0: (105 ticks this GP) idle=786/1/0x4000000000000000 softirq=536/641 fqs=16253
[ 68.241000] rcu: 84-...0: (99 ticks this GP) idle=292/1/0x4000000000000000 softirq=537/537 fqs=16253
[ 68.241000] rcu: 111-...0: (104 ticks this GP) idle=bde/1/0x4000000000000000 softirq=474/476 fqs=16253
[ 68.241000] rcu: (detected by 13, t=65018 jiffies, g=249, q=2)
The long init time was mainly caused by the call to kasan_free_pages() to
poison the newly initialized pages. On a 4TB system, we are talking about
almost 500GB of memory probably on the same node.
In reality, we may not need to poison the newly initialized pages before
they are ever allocated. So KASAN poisoning of freed pages before the
completion of deferred memory initialization is now disabled. Those pages
will be properly poisoned when they are allocated or freed after deferred
pages initialization is done.
With this change, the new page initialization time became:
[ 21.948010] node 1 initialised, 132075466 pages in 18702ms
This was still about double the non-debug kernel time, but was much
better than before.
Link: http://lkml.kernel.org/r/1544459388-8736-1-git-send-email-longman@redhat.com
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, NR_PAGEBLOCK_BITS and MIGRATE_TYPES are not associated by code.
If someone adds extra migrate type, then he may forget to enlarge the
NR_PAGEBLOCK_BITS. Hence it requires some way to fix.
NR_PAGEBLOCK_BITS depends on MIGRATE_TYPES, while these macro spread on
two different .h file with reverse dependency, it is a little hard to
refer to MIGRATE_TYPES in pageblock-flag.h. This patch tries to remind
such relation in compiling-time.
Link: http://lkml.kernel.org/r/1544508709-11358-1-git-send-email-kernelfans@gmail.com
Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since commit 03e85f9d5f ("mm/page_alloc: Introduce
free_area_init_core_hotplug"), some functions changed to only be called
during system initialization. Concretly, free_area_init_node() and the
functions that hang from it.
Also, some variables are no longer used after the system has gone
through initialization. So this could be considered as a late clean-up
for that patch.
This patch changes the functions from __meminit to __init, and the
variables from __meminitdata to __initdata.
In return, we get some KBs back:
Before:
Freeing unused kernel image memory: 2472K
After:
Freeing unused kernel image memory: 2480K
Link: http://lkml.kernel.org/r/20181204111507.4808-1-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Wei Yang <richard.weiyang@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When DEFERRED_STRUCT_PAGE_INIT is configured, only the first section of
each node's highest zone is initialized before defer stage.
static_init_pgcnt is used to store the number of pages like this:
pgdat->static_init_pgcnt = min_t(unsigned long, PAGES_PER_SECTION,
pgdat->node_spanned_pages);
because we don't want to overflow zone's range.
But this is not necessary, since defer_init() is called like this:
memmap_init_zone()
for pfn in [start_pfn, end_pfn)
defer_init(pfn, end_pfn)
In case (pgdat->node_spanned_pages < PAGES_PER_SECTION), the loop would
stop before calling defer_init().
BTW, comparing PAGES_PER_SECTION with node_spanned_pages is not correct,
since nr_initialised is zone based instead of node based. Even
node_spanned_pages is bigger than PAGES_PER_SECTION, its highest zone
would have pages less than PAGES_PER_SECTION.
Link: http://lkml.kernel.org/r/20181122094807.6985-1-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
and propagate through down the call stack.
Link: http://lkml.kernel.org/r/20181124091411.GC10969@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Those strings are immutable in fact.
Link: http://lkml.kernel.org/r/20181124090327.GA10877@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
An external fragmentation event was previously described as
When the page allocator fragments memory, it records the event using
the mm_page_alloc_extfrag event. If the fallback_order is smaller
than a pageblock order (order-9 on 64-bit x86) then it's considered
an event that will cause external fragmentation issues in the future.
The kernel reduces the probability of such events by increasing the
watermark sizes by calling set_recommended_min_free_kbytes early in the
lifetime of the system. This works reasonably well in general but if
there are enough sparsely populated pageblocks then the problem can still
occur as enough memory is free overall and kswapd stays asleep.
This patch introduces a watermark_boost_factor sysctl that allows a zone
watermark to be temporarily boosted when an external fragmentation causing
events occurs. The boosting will stall allocations that would decrease
free memory below the boosted low watermark and kswapd is woken if the
calling context allows to reclaim an amount of memory relative to the size
of the high watermark and the watermark_boost_factor until the boost is
cleared. When kswapd finishes, it wakes kcompactd at the pageblock order
to clean some of the pageblocks that may have been affected by the
fragmentation event. kswapd avoids any writeback, slab shrinkage and swap
from reclaim context during this operation to avoid excessive system
disruption in the name of fragmentation avoidance. Care is taken so that
kswapd will do normal reclaim work if the system is really low on memory.
This was evaluated using the same workloads as "mm, page_alloc: Spread
allocations across zones before introducing fragmentation".
1-socket Skylake machine
config-global-dhp__workload_thpfioscale XFS (no special madvise)
4 fio threads, 1 THP allocating thread
--------------------------------------
4.20-rc3 extfrag events < order 9: 804694
4.20-rc3+patch: 408912 (49% reduction)
4.20-rc3+patch1-4: 18421 (98% reduction)
4.20.0-rc3 4.20.0-rc3
lowzone-v5r8 boost-v5r8
Amean fault-base-1 653.58 ( 0.00%) 652.71 ( 0.13%)
Amean fault-huge-1 0.00 ( 0.00%) 178.93 * -99.00%*
4.20.0-rc3 4.20.0-rc3
lowzone-v5r8 boost-v5r8
Percentage huge-1 0.00 ( 0.00%) 5.12 ( 100.00%)
Note that external fragmentation causing events are massively reduced by
this path whether in comparison to the previous kernel or the vanilla
kernel. The fault latency for huge pages appears to be increased but that
is only because THP allocations were successful with the patch applied.
1-socket Skylake machine
global-dhp__workload_thpfioscale-madvhugepage-xfs (MADV_HUGEPAGE)
-----------------------------------------------------------------
4.20-rc3 extfrag events < order 9: 291392
4.20-rc3+patch: 191187 (34% reduction)
4.20-rc3+patch1-4: 13464 (95% reduction)
thpfioscale Fault Latencies
4.20.0-rc3 4.20.0-rc3
lowzone-v5r8 boost-v5r8
Min fault-base-1 912.00 ( 0.00%) 905.00 ( 0.77%)
Min fault-huge-1 127.00 ( 0.00%) 135.00 ( -6.30%)
Amean fault-base-1 1467.55 ( 0.00%) 1481.67 ( -0.96%)
Amean fault-huge-1 1127.11 ( 0.00%) 1063.88 * 5.61%*
4.20.0-rc3 4.20.0-rc3
lowzone-v5r8 boost-v5r8
Percentage huge-1 77.64 ( 0.00%) 83.46 ( 7.49%)
As before, massive reduction in external fragmentation events, some jitter
on latencies and an increase in THP allocation success rates.
2-socket Haswell machine
config-global-dhp__workload_thpfioscale XFS (no special madvise)
4 fio threads, 5 THP allocating threads
----------------------------------------------------------------
4.20-rc3 extfrag events < order 9: 215698
4.20-rc3+patch: 200210 (7% reduction)
4.20-rc3+patch1-4: 14263 (93% reduction)
4.20.0-rc3 4.20.0-rc3
lowzone-v5r8 boost-v5r8
Amean fault-base-5 1346.45 ( 0.00%) 1306.87 ( 2.94%)
Amean fault-huge-5 3418.60 ( 0.00%) 1348.94 ( 60.54%)
4.20.0-rc3 4.20.0-rc3
lowzone-v5r8 boost-v5r8
Percentage huge-5 0.78 ( 0.00%) 7.91 ( 910.64%)
There is a 93% reduction in fragmentation causing events, there is a big
reduction in the huge page fault latency and allocation success rate is
higher.
2-socket Haswell machine
global-dhp__workload_thpfioscale-madvhugepage-xfs (MADV_HUGEPAGE)
-----------------------------------------------------------------
4.20-rc3 extfrag events < order 9: 166352
4.20-rc3+patch: 147463 (11% reduction)
4.20-rc3+patch1-4: 11095 (93% reduction)
thpfioscale Fault Latencies
4.20.0-rc3 4.20.0-rc3
lowzone-v5r8 boost-v5r8
Amean fault-base-5 6217.43 ( 0.00%) 7419.67 * -19.34%*
Amean fault-huge-5 3163.33 ( 0.00%) 3263.80 ( -3.18%)
4.20.0-rc3 4.20.0-rc3
lowzone-v5r8 boost-v5r8
Percentage huge-5 95.14 ( 0.00%) 87.98 ( -7.53%)
There is a large reduction in fragmentation events with some jitter around
the latencies and success rates. As before, the high THP allocation
success rate does mean the system is under a lot of pressure. However, as
the fragmentation events are reduced, it would be expected that the
long-term allocation success rate would be higher.
Link: http://lkml.kernel.org/r/20181123114528.28802-5-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a preparation patch that copies the GFP flag __GFP_KSWAPD_RECLAIM
into alloc_flags. This is a preparation patch only that avoids having to
pass gfp_mask through a long callchain in a future patch.
Note that the setting in the fast path happens in alloc_flags_nofragment()
and it may be claimed that this has nothing to do with ALLOC_NO_FRAGMENT.
That's true in this patch but is not true later so it's done now for
easier review to show where the flag needs to be recorded.
No functional change.
[mgorman@techsingularity.net: ALLOC_KSWAPD flag needs to be applied in the !CONFIG_ZONE_DMA32 case]
Link: http://lkml.kernel.org/r/20181126143503.GO23260@techsingularity.net
Link: http://lkml.kernel.org/r/20181123114528.28802-4-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a preparation patch only, no functional change.
Link: http://lkml.kernel.org/r/20181123114528.28802-3-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "Fragmentation avoidance improvements", v5.
It has been noted before that fragmentation avoidance (aka
anti-fragmentation) is not perfect. Given sufficient time or an adverse
workload, memory gets fragmented and the long-term success of high-order
allocations degrades. This series defines an adverse workload, a definition
of external fragmentation events (including serious) ones and a series
that reduces the level of those fragmentation events.
The details of the workload and the consequences are described in more
detail in the changelogs. However, from patch 1, this is a high-level
summary of the adverse workload. The exact details are found in the
mmtests implementation.
The broad details of the workload are as follows;
1. Create an XFS filesystem (not specified in the configuration but done
as part of the testing for this patch)
2. Start 4 fio threads that write a number of 64K files inefficiently.
Inefficiently means that files are created on first access and not
created in advance (fio parameterr create_on_open=1) and fallocate
is not used (fallocate=none). With multiple IO issuers this creates
a mix of slab and page cache allocations over time. The total size
of the files is 150% physical memory so that the slabs and page cache
pages get mixed
3. Warm up a number of fio read-only threads accessing the same files
created in step 2. This part runs for the same length of time it
took to create the files. It'll fault back in old data and further
interleave slab and page cache allocations. As it's now low on
memory due to step 2, fragmentation occurs as pageblocks get
stolen.
4. While step 3 is still running, start a process that tries to allocate
75% of memory as huge pages with a number of threads. The number of
threads is based on a (NR_CPUS_SOCKET - NR_FIO_THREADS)/4 to avoid THP
threads contending with fio, any other threads or forcing cross-NUMA
scheduling. Note that the test has not been used on a machine with less
than 8 cores. The benchmark records whether huge pages were allocated
and what the fault latency was in microseconds
5. Measure the number of events potentially causing external fragmentation,
the fault latency and the huge page allocation success rate.
6. Cleanup
Overall the series reduces external fragmentation causing events by over 94%
on 1 and 2 socket machines, which in turn impacts high-order allocation
success rates over the long term. There are differences in latencies and
high-order allocation success rates. Latencies are a mixed bag as they
are vulnerable to exact system state and whether allocations succeeded
so they are treated as a secondary metric.
Patch 1 uses lower zones if they are populated and have free memory
instead of fragmenting a higher zone. It's special cased to
handle a Normal->DMA32 fallback with the reasons explained
in the changelog.
Patch 2-4 boosts watermarks temporarily when an external fragmentation
event occurs. kswapd wakes to reclaim a small amount of old memory
and then wakes kcompactd on completion to recover the system
slightly. This introduces some overhead in the slowpath. The level
of boosting can be tuned or disabled depending on the tolerance
for fragmentation vs allocation latency.
Patch 5 stalls some movable allocation requests to let kswapd from patch 4
make some progress. The duration of the stalls is very low but it
is possible to tune the system to avoid fragmentation events if
larger stalls can be tolerated.
The bulk of the improvement in fragmentation avoidance is from patches
1-4 but patch 5 can deal with a rare corner case and provides the option
of tuning a system for THP allocation success rates in exchange for
some stalls to control fragmentation.
This patch (of 5):
The page allocator zone lists are iterated based on the watermarks of each
zone which does not take anti-fragmentation into account. On x86, node 0
may have multiple zones while other nodes have one zone. A consequence is
that tasks running on node 0 may fragment ZONE_NORMAL even though
ZONE_DMA32 has plenty of free memory. This patch special cases the
allocator fast path such that it'll try an allocation from a lower local
zone before fragmenting a higher zone. In this case, stealing of
pageblocks or orders larger than a pageblock are still allowed in the fast
path as they are uninteresting from a fragmentation point of view.
This was evaluated using a benchmark designed to fragment memory before
attempting THP allocations. It's implemented in mmtests as the following
configurations
configs/config-global-dhp__workload_thpfioscale
configs/config-global-dhp__workload_thpfioscale-defrag
configs/config-global-dhp__workload_thpfioscale-madvhugepage
e.g. from mmtests
./run-mmtests.sh --run-monitor --config configs/config-global-dhp__workload_thpfioscale test-run-1
The broad details of the workload are as follows;
1. Create an XFS filesystem (not specified in the configuration but done
as part of the testing for this patch).
2. Start 4 fio threads that write a number of 64K files inefficiently.
Inefficiently means that files are created on first access and not
created in advance (fio parameter create_on_open=1) and fallocate
is not used (fallocate=none). With multiple IO issuers this creates
a mix of slab and page cache allocations over time. The total size
of the files is 150% physical memory so that the slabs and page cache
pages get mixed.
3. Warm up a number of fio read-only processes accessing the same files
created in step 2. This part runs for the same length of time it
took to create the files. It'll refault old data and further
interleave slab and page cache allocations. As it's now low on
memory due to step 2, fragmentation occurs as pageblocks get
stolen.
4. While step 3 is still running, start a process that tries to allocate
75% of memory as huge pages with a number of threads. The number of
threads is based on a (NR_CPUS_SOCKET - NR_FIO_THREADS)/4 to avoid THP
threads contending with fio, any other threads or forcing cross-NUMA
scheduling. Note that the test has not been used on a machine with less
than 8 cores. The benchmark records whether huge pages were allocated
and what the fault latency was in microseconds.
5. Measure the number of events potentially causing external fragmentation,
the fault latency and the huge page allocation success rate.
6. Cleanup the test files.
Note that due to the use of IO and page cache that this benchmark is not
suitable for running on large machines where the time to fragment memory
may be excessive. Also note that while this is one mix that generates
fragmentation that it's not the only mix that generates fragmentation.
Differences in workload that are more slab-intensive or whether SLUB is
used with high-order pages may yield different results.
When the page allocator fragments memory, it records the event using the
mm_page_alloc_extfrag ftrace event. If the fallback_order is smaller than
a pageblock order (order-9 on 64-bit x86) then it's considered to be an
"external fragmentation event" that may cause issues in the future.
Hence, the primary metric here is the number of external fragmentation
events that occur with order < 9. The secondary metric is allocation
latency and huge page allocation success rates but note that differences
in latencies and what the success rate also can affect the number of
external fragmentation event which is why it's a secondary metric.
1-socket Skylake machine
config-global-dhp__workload_thpfioscale XFS (no special madvise)
4 fio threads, 1 THP allocating thread
--------------------------------------
4.20-rc3 extfrag events < order 9: 804694
4.20-rc3+patch: 408912 (49% reduction)
thpfioscale Fault Latencies
4.20.0-rc3 4.20.0-rc3
vanilla lowzone-v5r8
Amean fault-base-1 662.92 ( 0.00%) 653.58 * 1.41%*
Amean fault-huge-1 0.00 ( 0.00%) 0.00 ( 0.00%)
4.20.0-rc3 4.20.0-rc3
vanilla lowzone-v5r8
Percentage huge-1 0.00 ( 0.00%) 0.00 ( 0.00%)
Fault latencies are slightly reduced while allocation success rates remain
at zero as this configuration does not make any special effort to allocate
THP and fio is heavily active at the time and either filling memory or
keeping pages resident. However, a 49% reduction of serious fragmentation
events reduces the changes of external fragmentation being a problem in
the future.
Vlastimil asked during review for a breakdown of the allocation types
that are falling back.
vanilla
3816 MIGRATE_UNMOVABLE
800845 MIGRATE_MOVABLE
33 MIGRATE_UNRECLAIMABLE
patch
735 MIGRATE_UNMOVABLE
408135 MIGRATE_MOVABLE
42 MIGRATE_UNRECLAIMABLE
The majority of the fallbacks are due to movable allocations and this is
consistent for the workload throughout the series so will not be presented
again as the primary source of fallbacks are movable allocations.
Movable fallbacks are sometimes considered "ok" to fallback because they
can be migrated. The problem is that they can fill an
unmovable/reclaimable pageblock causing those allocations to fallback
later and polluting pageblocks with pages that cannot move. If there is a
movable fallback, it is pretty much guaranteed to affect an
unmovable/reclaimable pageblock and while it might not be enough to
actually cause a unmovable/reclaimable fallback in the future, we cannot
know that in advance so the patch takes the only option available to it.
Hence, it's important to control them. This point is also consistent
throughout the series and will not be repeated.
1-socket Skylake machine
global-dhp__workload_thpfioscale-madvhugepage-xfs (MADV_HUGEPAGE)
-----------------------------------------------------------------
4.20-rc3 extfrag events < order 9: 291392
4.20-rc3+patch: 191187 (34% reduction)
thpfioscale Fault Latencies
4.20.0-rc3 4.20.0-rc3
vanilla lowzone-v5r8
Amean fault-base-1 1495.14 ( 0.00%) 1467.55 ( 1.85%)
Amean fault-huge-1 1098.48 ( 0.00%) 1127.11 ( -2.61%)
thpfioscale Percentage Faults Huge
4.20.0-rc3 4.20.0-rc3
vanilla lowzone-v5r8
Percentage huge-1 78.57 ( 0.00%) 77.64 ( -1.18%)
Fragmentation events were reduced quite a bit although this is known
to be a little variable. The latencies and allocation success rates
are similar but they were already quite high.
2-socket Haswell machine
config-global-dhp__workload_thpfioscale XFS (no special madvise)
4 fio threads, 5 THP allocating threads
----------------------------------------------------------------
4.20-rc3 extfrag events < order 9: 215698
4.20-rc3+patch: 200210 (7% reduction)
thpfioscale Fault Latencies
4.20.0-rc3 4.20.0-rc3
vanilla lowzone-v5r8
Amean fault-base-5 1350.05 ( 0.00%) 1346.45 ( 0.27%)
Amean fault-huge-5 4181.01 ( 0.00%) 3418.60 ( 18.24%)
4.20.0-rc3 4.20.0-rc3
vanilla lowzone-v5r8
Percentage huge-5 1.15 ( 0.00%) 0.78 ( -31.88%)
The reduction of external fragmentation events is slight and this is
partially due to the removal of __GFP_THISNODE in commit ac5b2c1891
("mm: thp: relax __GFP_THISNODE for MADV_HUGEPAGE mappings") as THP
allocations can now spill over to remote nodes instead of fragmenting
local memory.
2-socket Haswell machine
global-dhp__workload_thpfioscale-madvhugepage-xfs (MADV_HUGEPAGE)
-----------------------------------------------------------------
4.20-rc3 extfrag events < order 9: 166352
4.20-rc3+patch: 147463 (11% reduction)
thpfioscale Fault Latencies
4.20.0-rc3 4.20.0-rc3
vanilla lowzone-v5r8
Amean fault-base-5 6138.97 ( 0.00%) 6217.43 ( -1.28%)
Amean fault-huge-5 2294.28 ( 0.00%) 3163.33 * -37.88%*
thpfioscale Percentage Faults Huge
4.20.0-rc3 4.20.0-rc3
vanilla lowzone-v5r8
Percentage huge-5 96.82 ( 0.00%) 95.14 ( -1.74%)
There was a slight reduction in external fragmentation events although the
latencies were higher. The allocation success rate is high enough that
the system is struggling and there is quite a lot of parallel reclaim and
compaction activity. There is also a certain degree of luck on whether
processes start on node 0 or not for this patch but the relevance is
reduced later in the series.
Overall, the patch reduces the number of external fragmentation causing
events so the success of THP over long periods of time would be improved
for this adverse workload.
Link: http://lkml.kernel.org/r/20181123114528.28802-2-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are multiple places of freeing a page, they all do the same things
so a common function can be used to reduce code duplicate.
It also avoids bug fixed in one function but left in another.
Link: http://lkml.kernel.org/r/20181119134834.17765-3-aaron.lu@intel.com
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Pankaj gupta <pagupta@redhat.com>
Cc: Pawel Staszewski <pstaszewski@itcare.pl>
Cc: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
page_frag_free() calls __free_pages_ok() to free the page back to Buddy.
This is OK for high order page, but for order-0 pages, it misses the
optimization opportunity of using Per-Cpu-Pages and can cause zone lock
contention when called frequently.
Pawel Staszewski recently shared his result of 'how Linux kernel handles
normal traffic'[1] and from perf data, Jesper Dangaard Brouer found the
lock contention comes from page allocator:
mlx5e_poll_tx_cq
|
--16.34%--napi_consume_skb
|
|--12.65%--__free_pages_ok
| |
| --11.86%--free_one_page
| |
| |--10.10%--queued_spin_lock_slowpath
| |
| --0.65%--_raw_spin_lock
|
|--1.55%--page_frag_free
|
--1.44%--skb_release_data
Jesper explained how it happened: mlx5 driver RX-page recycle mechanism is
not effective in this workload and pages have to go through the page
allocator. The lock contention happens during mlx5 DMA TX completion
cycle. And the page allocator cannot keep up at these speeds.[2]
I thought that __free_pages_ok() are mostly freeing high order pages and
thought this is an lock contention for high order pages but Jesper
explained in detail that __free_pages_ok() here are actually freeing
order-0 pages because mlx5 is using order-0 pages to satisfy its page pool
allocation request.[3]
The free path as pointed out by Jesper is:
skb_free_head()
-> skb_free_frag()
-> page_frag_free()
And the pages being freed on this path are order-0 pages.
Fix this by doing similar things as in __page_frag_cache_drain() - send
the being freed page to PCP if it's an order-0 page, or directly to Buddy
if it is a high order page.
With this change, Paweł hasn't noticed lock contention yet in his
workload and Jesper has noticed a 7% performance improvement using a micro
benchmark and lock contention is gone. Ilias' test on a 'low' speed 1Gbit
interface on an cortex-a53 shows ~11% performance boost testing with
64byte packets and __free_pages_ok() disappeared from perf top.
[1]: https://www.spinics.net/lists/netdev/msg531362.html
[2]: https://www.spinics.net/lists/netdev/msg531421.html
[3]: https://www.spinics.net/lists/netdev/msg531556.html
[akpm@linux-foundation.org: add comment]
Link: http://lkml.kernel.org/r/20181120014544.GB10657@intel.com
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Reported-by: Pawel Staszewski <pstaszewski@itcare.pl>
Analysed-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Tested-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Acked-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Acked-by: Tariq Toukan <tariqt@mellanox.com>
Acked-by: Pankaj gupta <pagupta@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In the enum migratetype definition, MIGRATE_MOVABLE is before
MIGRATE_RECLAIMABLE. Change the order of them to match the enumeration's
order.
Link: http://lkml.kernel.org/r/20181121085821.3442-1-sjhuang@iluvatar.ai
Signed-off-by: Huang Shijie <sjhuang@iluvatar.ai>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that totalram_pages and managed_pages are atomic varibles, no need of
managed_page_count spinlock. The lock had really a weak consistency
guarantee. It hasn't been used for anything but the update but no reader
actually cares about all the values being updated to be in sync.
Link: http://lkml.kernel.org/r/1542090790-21750-5-git-send-email-arunks@codeaurora.org
Signed-off-by: Arun KS <arunks@codeaurora.org>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
totalram_pages and totalhigh_pages are made static inline function.
Main motivation was that managed_page_count_lock handling was complicating
things. It was discussed in length here,
https://lore.kernel.org/patchwork/patch/995739/#1181785 So it seemes
better to remove the lock and convert variables to atomic, with preventing
poteintial store-to-read tearing as a bonus.
[akpm@linux-foundation.org: coding style fixes]
Link: http://lkml.kernel.org/r/1542090790-21750-4-git-send-email-arunks@codeaurora.org
Signed-off-by: Arun KS <arunks@codeaurora.org>
Suggested-by: Michal Hocko <mhocko@suse.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
totalram_pages, zone->managed_pages and totalhigh_pages updates are
protected by managed_page_count_lock, but readers never care about it.
Convert these variables to atomic to avoid readers potentially seeing a
store tear.
This patch converts zone->managed_pages. Subsequent patches will convert
totalram_panges, totalhigh_pages and eventually managed_page_count_lock
will be removed.
Main motivation was that managed_page_count_lock handling was complicating
things. It was discussed in length here,
https://lore.kernel.org/patchwork/patch/995739/#1181785 So it seemes
better to remove the lock and convert variables to atomic, with preventing
poteintial store-to-read tearing as a bonus.
Link: http://lkml.kernel.org/r/1542090790-21750-3-git-send-email-arunks@codeaurora.org
Signed-off-by: Arun KS <arunks@codeaurora.org>
Suggested-by: Michal Hocko <mhocko@suse.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm: convert totalram_pages, totalhigh_pages and managed
pages to atomic", v5.
This series converts totalram_pages, totalhigh_pages and
zone->managed_pages to atomic variables.
totalram_pages, zone->managed_pages and totalhigh_pages updates are
protected by managed_page_count_lock, but readers never care about it.
Convert these variables to atomic to avoid readers potentially seeing a
store tear.
Main motivation was that managed_page_count_lock handling was complicating
things. It was discussed in length here,
https://lore.kernel.org/patchwork/patch/995739/#1181785 It seemes better
to remove the lock and convert variables to atomic. With the change,
preventing poteintial store-to-read tearing comes as a bonus.
This patch (of 4):
This is in preparation to a later patch which converts totalram_pages and
zone->managed_pages to atomic variables. Please note that re-reading the
value might lead to a different value and as such it could lead to
unexpected behavior. There are no known bugs as a result of the current
code but it is better to prevent from them in principle.
Link: http://lkml.kernel.org/r/1542090790-21750-2-git-send-email-arunks@codeaurora.org
Signed-off-by: Arun KS <arunks@codeaurora.org>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
per_cpu_pageset is cleared by memset, it is not necessary to reset it
again.
Link: http://lkml.kernel.org/r/20181021023920.5501-1-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Heiko has complained that his log is swamped by warnings from
has_unmovable_pages
[ 20.536664] page dumped because: has_unmovable_pages
[ 20.536792] page:000003d081ff4080 count:1 mapcount:0 mapping:000000008ff88600 index:0x0 compound_mapcount: 0
[ 20.536794] flags: 0x3fffe0000010200(slab|head)
[ 20.536795] raw: 03fffe0000010200 0000000000000100 0000000000000200 000000008ff88600
[ 20.536796] raw: 0000000000000000 0020004100000000 ffffffff00000001 0000000000000000
[ 20.536797] page dumped because: has_unmovable_pages
[ 20.536814] page:000003d0823b0000 count:1 mapcount:0 mapping:0000000000000000 index:0x0
[ 20.536815] flags: 0x7fffe0000000000()
[ 20.536817] raw: 07fffe0000000000 0000000000000100 0000000000000200 0000000000000000
[ 20.536818] raw: 0000000000000000 0000000000000000 ffffffff00000001 0000000000000000
which are not triggered by the memory hotplug but rather CMA allocator.
The original idea behind dumping the page state for all call paths was
that these messages will be helpful debugging failures. From the above it
seems that this is not the case for the CMA path because we are lacking
much more context. E.g the second reported page might be a CMA allocated
page. It is still interesting to see a slab page in the CMA area but it
is hard to tell whether this is bug from the above output alone.
Address this issue by dumping the page state only on request. Both
start_isolate_page_range and has_unmovable_pages already have an argument
to ignore hwpoison pages so make this argument more generic and turn it
into flags and allow callers to combine non-default modes into a mask.
While we are at it, has_unmovable_pages call from
is_pageblock_removable_nolock (sysfs removable file) is questionable to
report the failure so drop it from there as well.
Link: http://lkml.kernel.org/r/20181218092802.31429-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is only very limited information printed when the memory offlining
fails:
[ 1984.506184] rac1 kernel: memory offlining [mem 0x82600000000-0x8267fffffff] failed due to signal backoff
This tells us that the failure is triggered by the userspace intervention
but it doesn't tell us much more about the underlying reason. It might be
that the page migration failes repeatedly and the userspace timeout
expires and send a signal or it might be some of the earlier steps
(isolation, memory notifier) takes too long.
If the migration failes then it would be really helpful to see which page
that and its state. The same applies to the isolation phase. If we fail
to isolate a page from the allocator then knowing the state of the page
would be helpful as well.
Dump the page state that fails to get isolated or migrated. This will
tell us more about the failure and what to focus on during debugging.
[akpm@linux-foundation.org: add missing printk arg]
[mhocko@suse.com: tweak dump_page() `reason' text]
Link: http://lkml.kernel.org/r/20181116083020.20260-6-mhocko@kernel.org
Link: http://lkml.kernel.org/r/20181107101830.17405-6-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Oscar Salvador <OSalvador@suse.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tag-based KASAN doesn't check memory accesses through pointers tagged with
0xff. When page_address is used to get pointer to memory that corresponds
to some page, the tag of the resulting pointer gets set to 0xff, even
though the allocated memory might have been tagged differently.
For slab pages it's impossible to recover the correct tag to return from
page_address, since the page might contain multiple slab objects tagged
with different values, and we can't know in advance which one of them is
going to get accessed. For non slab pages however, we can recover the tag
in page_address, since the whole page was marked with the same tag.
This patch adds tagging to non slab memory allocated with pagealloc. To
set the tag of the pointer returned from page_address, the tag gets stored
to page->flags when the memory gets allocated.
Link: http://lkml.kernel.org/r/d758ddcef46a5abc9970182b9137e2fbee202a2c.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
While playing with gigantic hugepages and memory_hotplug, I triggered
the following #PF when "cat memoryX/removable":
BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
#PF error: [normal kernel read fault]
PGD 0 P4D 0
Oops: 0000 [#1] SMP PTI
CPU: 1 PID: 1481 Comm: cat Tainted: G E 4.20.0-rc6-mm1-1-default+ #18
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014
RIP: 0010:has_unmovable_pages+0x154/0x210
Call Trace:
is_mem_section_removable+0x7d/0x100
removable_show+0x90/0xb0
dev_attr_show+0x1c/0x50
sysfs_kf_seq_show+0xca/0x1b0
seq_read+0x133/0x380
__vfs_read+0x26/0x180
vfs_read+0x89/0x140
ksys_read+0x42/0x90
do_syscall_64+0x5b/0x180
entry_SYSCALL_64_after_hwframe+0x44/0xa9
The reason is we do not pass the Head to page_hstate(), and so, the call
to compound_order() in page_hstate() returns 0, so we end up checking
all hstates's size to match PAGE_SIZE.
Obviously, we do not find any hstate matching that size, and we return
NULL. Then, we dereference that NULL pointer in
hugepage_migration_supported() and we got the #PF from above.
Fix that by getting the head page before calling page_hstate().
Also, since gigantic pages span several pageblocks, re-adjust the logic
for skipping pages. While are it, we can also get rid of the
round_up().
[osalvador@suse.de: remove round_up(), adjust skip pages logic per Michal]
Link: http://lkml.kernel.org/r/20181221062809.31771-1-osalvador@suse.de
Link: http://lkml.kernel.org/r/20181217225113.17864-1-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If memory end is not aligned with the sparse memory section boundary,
the mapping of such a section is only partly initialized. This may lead
to VM_BUG_ON due to uninitialized struct page access from
is_mem_section_removable() or test_pages_in_a_zone() function triggered
by memory_hotplug sysfs handlers:
Here are the the panic examples:
CONFIG_DEBUG_VM=y
CONFIG_DEBUG_VM_PGFLAGS=y
kernel parameter mem=2050M
--------------------------
page:000003d082008000 is uninitialized and poisoned
page dumped because: VM_BUG_ON_PAGE(PagePoisoned(p))
Call Trace:
( test_pages_in_a_zone+0xde/0x160)
show_valid_zones+0x5c/0x190
dev_attr_show+0x34/0x70
sysfs_kf_seq_show+0xc8/0x148
seq_read+0x204/0x480
__vfs_read+0x32/0x178
vfs_read+0x82/0x138
ksys_read+0x5a/0xb0
system_call+0xdc/0x2d8
Last Breaking-Event-Address:
test_pages_in_a_zone+0xde/0x160
Kernel panic - not syncing: Fatal exception: panic_on_oops
kernel parameter mem=3075M
--------------------------
page:000003d08300c000 is uninitialized and poisoned
page dumped because: VM_BUG_ON_PAGE(PagePoisoned(p))
Call Trace:
( is_mem_section_removable+0xb4/0x190)
show_mem_removable+0x9a/0xd8
dev_attr_show+0x34/0x70
sysfs_kf_seq_show+0xc8/0x148
seq_read+0x204/0x480
__vfs_read+0x32/0x178
vfs_read+0x82/0x138
ksys_read+0x5a/0xb0
system_call+0xdc/0x2d8
Last Breaking-Event-Address:
is_mem_section_removable+0xb4/0x190
Kernel panic - not syncing: Fatal exception: panic_on_oops
Fix the problem by initializing the last memory section of each zone in
memmap_init_zone() till the very end, even if it goes beyond the zone end.
Michal said:
: This has alwways been problem AFAIU. It just went unnoticed because we
: have zeroed memmaps during allocation before f7f99100d8 ("mm: stop
: zeroing memory during allocation in vmemmap") and so the above test
: would simply skip these ranges as belonging to zone 0 or provided a
: garbage.
:
: So I guess we do care for post f7f99100d8 kernels mostly and
: therefore Fixes: f7f99100d8 ("mm: stop zeroing memory during
: allocation in vmemmap")
Link: http://lkml.kernel.org/r/20181212172712.34019-2-zaslonko@linux.ibm.com
Fixes: f7f99100d8 ("mm: stop zeroing memory during allocation in vmemmap")
Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Suggested-by: Michal Hocko <mhocko@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Reported-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Tested-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
init_currently_empty_zone() will adjust pgdat->nr_zones and set it to
'zone_idx(zone) + 1' unconditionally. This is correct in the normal
case, while not exact in hot-plug situation.
This function is used in two places:
* free_area_init_core()
* move_pfn_range_to_zone()
In the first case, we are sure zone index increase monotonically. While
in the second one, this is under users control.
One way to reproduce this is:
----------------------------
1. create a virtual machine with empty node1
-m 4G,slots=32,maxmem=32G \
-smp 4,maxcpus=8 \
-numa node,nodeid=0,mem=4G,cpus=0-3 \
-numa node,nodeid=1,mem=0G,cpus=4-7
2. hot-add cpu 3-7
cpu-add [3-7]
2. hot-add memory to nod1
object_add memory-backend-ram,id=ram0,size=1G
device_add pc-dimm,id=dimm0,memdev=ram0,node=1
3. online memory with following order
echo online_movable > memory47/state
echo online > memory40/state
After this, node1 will have its nr_zones equals to (ZONE_NORMAL + 1)
instead of (ZONE_MOVABLE + 1).
Michal said:
"Having an incorrect nr_zones might result in all sorts of problems
which would be quite hard to debug (e.g. reclaim not considering the
movable zone). I do not expect many users would suffer from this it
but still this is trivial and obviously right thing to do so
backporting to the stable tree shouldn't be harmful (last famous
words)"
Link: http://lkml.kernel.org/r/20181117022022.9956-1-richard.weiyang@gmail.com
Fixes: f1dd2cd13c ("mm, memory_hotplug: do not associate hotadded memory to zones until online")
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Konstantin has noticed that kvmalloc might trigger the following
warning:
WARNING: CPU: 0 PID: 6676 at mm/vmstat.c:986 __fragmentation_index+0x54/0x60
[...]
Call Trace:
fragmentation_index+0x76/0x90
compaction_suitable+0x4f/0xf0
shrink_node+0x295/0x310
node_reclaim+0x205/0x250
get_page_from_freelist+0x649/0xad0
__alloc_pages_nodemask+0x12a/0x2a0
kmalloc_large_node+0x47/0x90
__kmalloc_node+0x22b/0x2e0
kvmalloc_node+0x3e/0x70
xt_alloc_table_info+0x3a/0x80 [x_tables]
do_ip6t_set_ctl+0xcd/0x1c0 [ip6_tables]
nf_setsockopt+0x44/0x60
SyS_setsockopt+0x6f/0xc0
do_syscall_64+0x67/0x120
entry_SYSCALL_64_after_hwframe+0x3d/0xa2
the problem is that we only check for an out of bound order in the slow
path and the node reclaim might happen from the fast path already. This
is fixable by making sure that kvmalloc doesn't ever use kmalloc for
requests that are larger than KMALLOC_MAX_SIZE but this also shows that
the code is rather fragile. A recent UBSAN report just underlines that
by the following report
UBSAN: Undefined behaviour in mm/page_alloc.c:3117:19
shift exponent 51 is too large for 32-bit type 'int'
CPU: 0 PID: 6520 Comm: syz-executor1 Not tainted 4.19.0-rc2 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0xd2/0x148 lib/dump_stack.c:113
ubsan_epilogue+0x12/0x94 lib/ubsan.c:159
__ubsan_handle_shift_out_of_bounds+0x2b6/0x30b lib/ubsan.c:425
__zone_watermark_ok+0x2c7/0x400 mm/page_alloc.c:3117
zone_watermark_fast mm/page_alloc.c:3216 [inline]
get_page_from_freelist+0xc49/0x44c0 mm/page_alloc.c:3300
__alloc_pages_nodemask+0x21e/0x640 mm/page_alloc.c:4370
alloc_pages_current+0xcc/0x210 mm/mempolicy.c:2093
alloc_pages include/linux/gfp.h:509 [inline]
__get_free_pages+0x12/0x60 mm/page_alloc.c:4414
dma_mem_alloc+0x36/0x50 arch/x86/include/asm/floppy.h:156
raw_cmd_copyin drivers/block/floppy.c:3159 [inline]
raw_cmd_ioctl drivers/block/floppy.c:3206 [inline]
fd_locked_ioctl+0xa00/0x2c10 drivers/block/floppy.c:3544
fd_ioctl+0x40/0x60 drivers/block/floppy.c:3571
__blkdev_driver_ioctl block/ioctl.c:303 [inline]
blkdev_ioctl+0xb3c/0x1a30 block/ioctl.c:601
block_ioctl+0x105/0x150 fs/block_dev.c:1883
vfs_ioctl fs/ioctl.c:46 [inline]
do_vfs_ioctl+0x1c0/0x1150 fs/ioctl.c:687
ksys_ioctl+0x9e/0xb0 fs/ioctl.c:702
__do_sys_ioctl fs/ioctl.c:709 [inline]
__se_sys_ioctl fs/ioctl.c:707 [inline]
__x64_sys_ioctl+0x7e/0xc0 fs/ioctl.c:707
do_syscall_64+0xc4/0x510 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Note that this is not a kvmalloc path. It is just that the fast path
really depends on having sanitzed order as well. Therefore move the
order check to the fast path.
Link: http://lkml.kernel.org/r/20181113094305.GM15120@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reported-by: Kyungtae Kim <kt0755@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Byoungyoung Lee <lifeasageek@gmail.com>
Cc: "Dae R. Jeong" <threeearcat@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Page state checks are racy. Under a heavy memory workload (e.g. stress
-m 200 -t 2h) it is quite easy to hit a race window when the page is
allocated but its state is not fully populated yet. A debugging patch to
dump the struct page state shows
has_unmovable_pages: pfn:0x10dfec00, found:0x1, count:0x0
page:ffffea0437fb0000 count:1 mapcount:1 mapping:ffff880e05239841 index:0x7f26e5000 compound_mapcount: 1
flags: 0x5fffffc0090034(uptodate|lru|active|head|swapbacked)
Note that the state has been checked for both PageLRU and PageSwapBacked
already. Closing this race completely would require some sort of retry
logic. This can be tricky and error prone (think of potential endless
or long taking loops).
Workaround this problem for movable zones at least. Such a zone should
only contain movable pages. Commit 15c30bc090 ("mm, memory_hotplug:
make has_unmovable_pages more robust") has told us that this is not
strictly true though. Bootmem pages should be marked reserved though so
we can move the original check after the PageReserved check. Pages from
other zones are still prone to races but we even do not pretend that
memory hotremove works for those so pre-mature failure doesn't hurt that
much.
Link: http://lkml.kernel.org/r/20181106095524.14629-1-mhocko@kernel.org
Fixes: 15c30bc090 ("mm, memory_hotplug: make has_unmovable_pages more robust")
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Baoquan He <bhe@redhat.com>
Tested-by: Baoquan He <bhe@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When a memblock allocation APIs are called with align = 0, the alignment
is implicitly set to SMP_CACHE_BYTES.
Implicit alignment is done deep in the memblock allocator and it can
come as a surprise. Not that such an alignment would be wrong even
when used incorrectly but it is better to be explicit for the sake of
clarity and the prinicple of the least surprise.
Replace all such uses of memblock APIs with the 'align' parameter
explicitly set to SMP_CACHE_BYTES and stop implicit alignment assignment
in the memblock internal allocation functions.
For the case when memblock APIs are used via helper functions, e.g. like
iommu_arena_new_node() in Alpha, the helper functions were detected with
Coccinelle's help and then manually examined and updated where
appropriate.
The direct memblock APIs users were updated using the semantic patch below:
@@
expression size, min_addr, max_addr, nid;
@@
(
|
- memblock_alloc_try_nid_raw(size, 0, min_addr, max_addr, nid)
+ memblock_alloc_try_nid_raw(size, SMP_CACHE_BYTES, min_addr, max_addr,
nid)
|
- memblock_alloc_try_nid_nopanic(size, 0, min_addr, max_addr, nid)
+ memblock_alloc_try_nid_nopanic(size, SMP_CACHE_BYTES, min_addr, max_addr,
nid)
|
- memblock_alloc_try_nid(size, 0, min_addr, max_addr, nid)
+ memblock_alloc_try_nid(size, SMP_CACHE_BYTES, min_addr, max_addr, nid)
|
- memblock_alloc(size, 0)
+ memblock_alloc(size, SMP_CACHE_BYTES)
|
- memblock_alloc_raw(size, 0)
+ memblock_alloc_raw(size, SMP_CACHE_BYTES)
|
- memblock_alloc_from(size, 0, min_addr)
+ memblock_alloc_from(size, SMP_CACHE_BYTES, min_addr)
|
- memblock_alloc_nopanic(size, 0)
+ memblock_alloc_nopanic(size, SMP_CACHE_BYTES)
|
- memblock_alloc_low(size, 0)
+ memblock_alloc_low(size, SMP_CACHE_BYTES)
|
- memblock_alloc_low_nopanic(size, 0)
+ memblock_alloc_low_nopanic(size, SMP_CACHE_BYTES)
|
- memblock_alloc_from_nopanic(size, 0, min_addr)
+ memblock_alloc_from_nopanic(size, SMP_CACHE_BYTES, min_addr)
|
- memblock_alloc_node(size, 0, nid)
+ memblock_alloc_node(size, SMP_CACHE_BYTES, nid)
)
[mhocko@suse.com: changelog update]
[akpm@linux-foundation.org: coding-style fixes]
[rppt@linux.ibm.com: fix missed uses of implicit alignment]
Link: http://lkml.kernel.org/r/20181016133656.GA10925@rapoport-lnx
Link: http://lkml.kernel.org/r/1538687224-17535-1-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Suggested-by: Michal Hocko <mhocko@suse.com>
Acked-by: Paul Burton <paul.burton@mips.com> [MIPS]
Acked-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc]
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move remaining definitions and declarations from include/linux/bootmem.h
into include/linux/memblock.h and remove the redundant header.
The includes were replaced with the semantic patch below and then
semi-automated removal of duplicated '#include <linux/memblock.h>
@@
@@
- #include <linux/bootmem.h>
+ #include <linux/memblock.h>
[sfr@canb.auug.org.au: dma-direct: fix up for the removal of linux/bootmem.h]
Link: http://lkml.kernel.org/r/20181002185342.133d1680@canb.auug.org.au
[sfr@canb.auug.org.au: powerpc: fix up for removal of linux/bootmem.h]
Link: http://lkml.kernel.org/r/20181005161406.73ef8727@canb.auug.org.au
[sfr@canb.auug.org.au: x86/kaslr, ACPI/NUMA: fix for linux/bootmem.h removal]
Link: http://lkml.kernel.org/r/20181008190341.5e396491@canb.auug.org.au
Link: http://lkml.kernel.org/r/1536927045-23536-30-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Serge Semin <fancer.lancer@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
All architecures use memblock for early memory management. There is no need
for the CONFIG_HAVE_MEMBLOCK configuration option.
[rppt@linux.vnet.ibm.com: of/fdt: fixup #ifdefs]
Link: http://lkml.kernel.org/r/20180919103457.GA20545@rapoport-lnx
[rppt@linux.vnet.ibm.com: csky: fixups after bootmem removal]
Link: http://lkml.kernel.org/r/20180926112744.GC4628@rapoport-lnx
[rppt@linux.vnet.ibm.com: remove stale #else and the code it protects]
Link: http://lkml.kernel.org/r/1538067825-24835-1-git-send-email-rppt@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/1536927045-23536-4-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Tested-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Serge Semin <fancer.lancer@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When checking for valid pfns in zero_resv_unavail(), it is not necessary
to verify that pfns within pageblock_nr_pages ranges are valid, only the
first one needs to be checked. This is because memory for pages are
allocated in contiguous chunks that contain pageblock_nr_pages struct
pages.
Link: http://lkml.kernel.org/r/20181002143821.5112-3-msys.mizuma@gmail.com
Signed-off-by: Pavel Tatashin <pavel.tatashin@microsoft.com>
Signed-off-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Reviewed-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm: Fix for movable_node boot option", v3.
This patch series contains a fix for the movable_node boot option issue
which was introduced by commit 124049decb ("x86/e820: put !E820_TYPE_RAM
regions into memblock.reserved").
The commit breaks the option because it changed the memory gap range to
reserved memblock. So, the node is marked as Normal zone even if the SRAT
has Hot pluggable affinity.
First and second patch fix the original issue which the commit tried to
fix, then revert the commit.
This patch (of 3):
There is a kernel panic that is triggered when reading /proc/kpageflags on
the kernel booted with kernel parameter 'memmap=nn[KMG]!ss[KMG]':
BUG: unable to handle kernel paging request at fffffffffffffffe
PGD 9b20e067 P4D 9b20e067 PUD 9b210067 PMD 0
Oops: 0000 [#1] SMP PTI
CPU: 2 PID: 1728 Comm: page-types Not tainted 4.17.0-rc6-mm1-v4.17-rc6-180605-0816-00236-g2dfb086ef02c+ #160
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.fc28 04/01/2014
RIP: 0010:stable_page_flags+0x27/0x3c0
Code: 00 00 00 0f 1f 44 00 00 48 85 ff 0f 84 a0 03 00 00 41 54 55 49 89 fc 53 48 8b 57 08 48 8b 2f 48 8d 42 ff 83 e2 01 48 0f 44 c7 <48> 8b 00 f6 c4 01 0f 84 10 03 00 00 31 db 49 8b 54 24 08 4c 89 e7
RSP: 0018:ffffbbd44111fde0 EFLAGS: 00010202
RAX: fffffffffffffffe RBX: 00007fffffffeff9 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 0000000000000202 RDI: ffffed1182fff5c0
RBP: ffffffffffffffff R08: 0000000000000001 R09: 0000000000000001
R10: ffffbbd44111fed8 R11: 0000000000000000 R12: ffffed1182fff5c0
R13: 00000000000bffd7 R14: 0000000002fff5c0 R15: ffffbbd44111ff10
FS: 00007efc4335a500(0000) GS:ffff93a5bfc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffffe CR3: 00000000b2a58000 CR4: 00000000001406e0
Call Trace:
kpageflags_read+0xc7/0x120
proc_reg_read+0x3c/0x60
__vfs_read+0x36/0x170
vfs_read+0x89/0x130
ksys_pread64+0x71/0x90
do_syscall_64+0x5b/0x160
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7efc42e75e23
Code: 09 00 ba 9f 01 00 00 e8 ab 81 f4 ff 66 2e 0f 1f 84 00 00 00 00 00 90 83 3d 29 0a 2d 00 00 75 13 49 89 ca b8 11 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 db d3 01 00 48 89 04 24
According to kernel bisection, this problem became visible due to commit
f7f99100d8 which changes how struct pages are initialized.
Memblock layout affects the pfn ranges covered by node/zone. Consider
that we have a VM with 2 NUMA nodes and each node has 4GB memory, and the
default (no memmap= given) memblock layout is like below:
MEMBLOCK configuration:
memory size = 0x00000001fff75c00 reserved size = 0x000000000300c000
memory.cnt = 0x4
memory[0x0] [0x0000000000001000-0x000000000009efff], 0x000000000009e000 bytes on node 0 flags: 0x0
memory[0x1] [0x0000000000100000-0x00000000bffd6fff], 0x00000000bfed7000 bytes on node 0 flags: 0x0
memory[0x2] [0x0000000100000000-0x000000013fffffff], 0x0000000040000000 bytes on node 0 flags: 0x0
memory[0x3] [0x0000000140000000-0x000000023fffffff], 0x0000000100000000 bytes on node 1 flags: 0x0
...
If you give memmap=1G!4G (so it just covers memory[0x2]),
the range [0x100000000-0x13fffffff] is gone:
MEMBLOCK configuration:
memory size = 0x00000001bff75c00 reserved size = 0x000000000300c000
memory.cnt = 0x3
memory[0x0] [0x0000000000001000-0x000000000009efff], 0x000000000009e000 bytes on node 0 flags: 0x0
memory[0x1] [0x0000000000100000-0x00000000bffd6fff], 0x00000000bfed7000 bytes on node 0 flags: 0x0
memory[0x2] [0x0000000140000000-0x000000023fffffff], 0x0000000100000000 bytes on node 1 flags: 0x0
...
This causes shrinking node 0's pfn range because it is calculated by the
address range of memblock.memory. So some of struct pages in the gap
range are left uninitialized.
We have a function zero_resv_unavail() which does zeroing the struct pages
outside memblock.memory, but currently it covers only the reserved
unavailable range (i.e. memblock.memory && !memblock.reserved). This
patch extends it to cover all unavailable range, which fixes the reported
issue.
Link: http://lkml.kernel.org/r/20181002143821.5112-2-msys.mizuma@gmail.com
Fixes: f7f99100d8 ("mm: stop zeroing memory during allocation in vmemmap")
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Tested-by: Oscar Salvador <osalvador@suse.de>
Tested-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Reviewed-by: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
memmap_init_zone, is getting complex, because it is called from different
contexts: hotplug, and during boot, and also because it must handle some
architecture quirks. One of them is mirrored memory.
Move the code that decides whether to skip mirrored memory outside of
memmap_init_zone, into a separate function.
[pasha.tatashin@oracle.com: uninline overlap_memmap_init()]
Link: http://lkml.kernel.org/r/20180726193509.3326-4-pasha.tatashin@oracle.com
Link: http://lkml.kernel.org/r/20180724235520.10200-4-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
update_defer_init() should be called only when struct page is about to be
initialized. Because it counts number of initialized struct pages, but
there we may skip struct pages if there is some mirrored memory.
So move, update_defer_init() after checking for mirrored memory.
Also, rename update_defer_init() to defer_init() and reverse the return
boolean to emphasize that this is a boolean function, that tells that the
reset of memmap initialization should be deferred.
Make this function self-contained: do not pass number of already
initialized pages in this zone by using static counters.
I found this bug by reading the code. The effect is that fewer than
expected struct pages are initialized early in boot, and it is possible
that in some corner cases we may fail to boot when mirrored pages are
used. The deferred on demand code should somewhat mitigate this. But
this still brings some inconsistencies compared to when booting without
mirrored pages, so it is better to fix.
[pasha.tatashin@oracle.com: add comment about defer_init's lack of locking]
Link: http://lkml.kernel.org/r/20180726193509.3326-3-pasha.tatashin@oracle.com
[akpm@linux-foundation.org: make defer_init non-inline, __meminit]
Link: http://lkml.kernel.org/r/20180724235520.10200-3-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
memmap_init is sometimes a macro sometimes a function based on
__HAVE_ARCH_MEMMAP_INIT. It is only a function on ia64. Make memmap_init
a weak function instead, and let ia64 redefine it.
Link: http://lkml.kernel.org/r/20180724235520.10200-2-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If move_freepages_block() returns 0 because !zone_spans_pfn(),
*num_movable can hold the value from the stack because it does not get
initialized in move_freepages().
Move the initialization to move_freepages_block() to guarantee the value
actually makes sense.
This currently doesn't affect its only caller where num_movable != NULL,
so no bug fix, but just more robust.
Link: http://lkml.kernel.org/r/alpine.DEB.2.21.1810051355490.212229@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The ZONE_DEVICE pages were being initialized in two locations. One was
with the memory_hotplug lock held and another was outside of that lock.
The problem with this is that it was nearly doubling the memory
initialization time. Instead of doing this twice, once while holding a
global lock and once without, I am opting to defer the initialization to
the one outside of the lock. This allows us to avoid serializing the
overhead for memory init and we can instead focus on per-node init times.
One issue I encountered is that devm_memremap_pages and
hmm_devmmem_pages_create were initializing only the pgmap field the same
way. One wasn't initializing hmm_data, and the other was initializing it
to a poison value. Since this is something that is exposed to the driver
in the case of hmm I am opting for a third option and just initializing
hmm_data to 0 since this is going to be exposed to unknown third party
drivers.
[alexander.h.duyck@linux.intel.com: fix reference count for pgmap in devm_memremap_pages]
Link: http://lkml.kernel.org/r/20181008233404.1909.37302.stgit@localhost.localdomain
Link: http://lkml.kernel.org/r/20180925202053.3576.66039.stgit@localhost.localdomain
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Reviewed-by: Pavel Tatashin <pavel.tatashin@microsoft.com>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It doesn't make much sense to use the atomic SetPageReserved at init time
when we are using memset to clear the memory and manipulating the page
flags via simple "&=" and "|=" operations in __init_single_page.
This patch adds a non-atomic version __SetPageReserved that can be used
during page init and shows about a 10% improvement in initialization times
on the systems I have available for testing. On those systems I saw
initialization times drop from around 35 seconds to around 32 seconds to
initialize a 3TB block of persistent memory. I believe the main advantage
of this is that it allows for more compiler optimization as the __set_bit
operation can be reordered whereas the atomic version cannot.
I tried adding a bit of documentation based on f1dd2cd13c ("mm,
memory_hotplug: do not associate hotadded memory to zones until online").
Ideally the reserved flag should be set earlier since there is a brief
window where the page is initialization via __init_single_page and we have
not set the PG_Reserved flag. I'm leaving that for a future patch set as
that will require a more significant refactor.
Link: http://lkml.kernel.org/r/20180925202018.3576.11607.stgit@localhost.localdomain
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Reviewed-by: Pavel Tatashin <pavel.tatashin@microsoft.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
should_suppress_show_mem() was introduced to reduce the overhead of
show_mem on large NUMA systems. Things have changed since then though.
Namely c78e93630d ("mm: do not walk all of system memory during
show_mem") has reduced the overhead considerably.
Moreover warn_alloc_show_mem clears SHOW_MEM_FILTER_NODES when called from
the IRQ context already so we are not printing per node stats.
Remove should_suppress_show_mem because we are losing potentially
interesting information about allocation failures. We have seen a bug
report where system gets unresponsive under memory pressure and there is
only
kernel: [2032243.696888] qlge 0000:8b:00.1 ql1: Could not get a page chunk, i=8, clean_idx =200 .
kernel: [2032243.710725] swapper/7: page allocation failure: order:1, mode:0x1084120(GFP_ATOMIC|__GFP_COLD|__GFP_COMP)
without an additional information for debugging. It would be great to see
the state of the page allocator at the moment.
Link: http://lkml.kernel.org/r/20180907114334.7088-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When systems are overcommitted and resources become contended, it's hard
to tell exactly the impact this has on workload productivity, or how close
the system is to lockups and OOM kills. In particular, when machines work
multiple jobs concurrently, the impact of overcommit in terms of latency
and throughput on the individual job can be enormous.
In order to maximize hardware utilization without sacrificing individual
job health or risk complete machine lockups, this patch implements a way
to quantify resource pressure in the system.
A kernel built with CONFIG_PSI=y creates files in /proc/pressure/ that
expose the percentage of time the system is stalled on CPU, memory, or IO,
respectively. Stall states are aggregate versions of the per-task delay
accounting delays:
cpu: some tasks are runnable but not executing on a CPU
memory: tasks are reclaiming, or waiting for swapin or thrashing cache
io: tasks are waiting for io completions
These percentages of walltime can be thought of as pressure percentages,
and they give a general sense of system health and productivity loss
incurred by resource overcommit. They can also indicate when the system
is approaching lockup scenarios and OOMs.
To do this, psi keeps track of the task states associated with each CPU
and samples the time they spend in stall states. Every 2 seconds, the
samples are averaged across CPUs - weighted by the CPUs' non-idle time to
eliminate artifacts from unused CPUs - and translated into percentages of
walltime. A running average of those percentages is maintained over 10s,
1m, and 5m periods (similar to the loadaverage).
[hannes@cmpxchg.org: doc fixlet, per Randy]
Link: http://lkml.kernel.org/r/20180828205625.GA14030@cmpxchg.org
[hannes@cmpxchg.org: code optimization]
Link: http://lkml.kernel.org/r/20180907175015.GA8479@cmpxchg.org
[hannes@cmpxchg.org: rename psi_clock() to psi_update_work(), per Peter]
Link: http://lkml.kernel.org/r/20180907145404.GB11088@cmpxchg.org
[hannes@cmpxchg.org: fix build]
Link: http://lkml.kernel.org/r/20180913014222.GA2370@cmpxchg.org
Link: http://lkml.kernel.org/r/20180828172258.3185-9-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Daniel Drake <drake@endlessm.com>
Tested-by: Suren Baghdasaryan <surenb@google.com>
Cc: Christopher Lameter <cl@linux.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Weiner <jweiner@fb.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Enderborg <peter.enderborg@sony.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The vmstat counter NR_INDIRECTLY_RECLAIMABLE_BYTES was introduced by
commit eb59254608 ("mm: introduce NR_INDIRECTLY_RECLAIMABLE_BYTES") with
the goal of accounting objects that can be reclaimed, but cannot be
allocated via a SLAB_RECLAIM_ACCOUNT cache. This is now possible via
kmalloc() with __GFP_RECLAIMABLE flag, and the dcache external names user
is converted.
The counter is however still useful for accounting direct page allocations
(i.e. not slab) with a shrinker, such as the ION page pool. So keep it,
and:
- change granularity to pages to be more like other counters; sub-page
allocations should be able to use kmalloc
- rename the counter to NR_KERNEL_MISC_RECLAIMABLE
- expose the counter again in vmstat as "nr_kernel_misc_reclaimable"; we can
again remove the check for not printing "hidden" counters
Link: http://lkml.kernel.org/r/20180731090649.16028-5-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Vijayanand Jitta <vjitta@codeaurora.org>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
check_for_memory() looks a bit confusing. First of all, we have this:
if (N_MEMORY == N_NORMAL_MEMORY)
return;
Checking the ENUM declaration, looks like N_MEMORY canot be equal to
N_NORMAL_MEMORY.
I could not find where N_MEMORY is set to N_NORMAL_MEMORY, or the other
way around either, so unless I am missing something, this condition will
never evaluate to true. It makes sense to get rid of it.
Moving forward, the operations within the loop look a bit confusing as
well.
We set N_HIGH_MEMORY unconditionally, and then we set N_NORMAL_MEMORY in
case we have CONFIG_HIGHMEM (N_NORMAL_MEMORY != N_HIGH_MEMORY) and zone <=
ZONE_NORMAL. (N_HIGH_MEMORY falls back to N_NORMAL_MEMORY on
!CONFIG_HIGHMEM systems, and that is why we can just go ahead and set
N_HIGH_MEMORY unconditionally)
Although this works, it is a bit subtle.
I think that this could be easier to follow:
First, we should only set N_HIGH_MEMORY in case we have CONFIG_HIGHMEM.
And then we should set N_NORMAL_MEMORY in case zone <= ZONE_NORMAL,
without further checking whether we have CONFIG_HIGHMEM or not.
Link: http://lkml.kernel.org/r/20180828210158.4617-1-osalvador@techadventures.net
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Michael Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tetsuo Handa has reported that it is possible to bypass the short sleep
for PF_WQ_WORKER threads which was introduced by commit 373ccbe592
("mm, vmstat: allow WQ concurrency to discover memory reclaim doesn't make
any progress") and lock up the system if OOM.
The primary reason is that WQ_MEM_RECLAIM WQs are not guaranteed to run
even when they have a rescuer available. Those workers might be essential
for reclaim to make a forward progress, however. If we are too unlucky
all the allocations requests can get stuck waiting for a WQ_MEM_RECLAIM
work item and the system is essentially stuck in an OOM condition without
much hope to move on. Tetsuo has seen the reclaim stuck on
drain_local_pages_wq or xlog_cil_push_work (xfs). There might be others.
Since should_reclaim_retry() should be a natural reschedule point,
let's do the short sleep for PF_WQ_WORKER threads unconditionally in
order to guarantee that other pending work items are started. This
will workaround this problem and it is less fragile than hunting down
when the sleep is missed. Having a single sleeping point is more
robust.
[akpm@linux-foundation.org: reflow comment to 80 cols to save a couple of lines]
Link: http://lkml.kernel.org/r/20180827135101.15700-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Debugged-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rate limiting of page migrations due to automatic NUMA balancing was
introduced to mitigate the worst-case scenario of migrating at high
frequency due to false sharing or slowly ping-ponging between nodes.
Since then, a lot of effort was spent on correctly identifying these
pages and avoiding unnecessary migrations and the safety net may no longer
be required.
Jirka Hladky reported a regression in 4.17 due to a scheduler patch that
avoids spreading STREAM tasks wide prematurely. However, once the task
was properly placed, it delayed migrating the memory due to rate limiting.
Increasing the limit fixed the problem for him.
Currently, the limit is hard-coded and does not account for the real
capabilities of the hardware. Even if an estimate was attempted, it would
not properly account for the number of memory controllers and it could
not account for the amount of bandwidth used for normal accesses. Rather
than fudging, this patch simply eliminates the rate limiting.
However, Jirka reports that a STREAM configuration using multiple
processes achieved similar performance to 4.16. In local tests, this patch
improved performance of STREAM relative to the baseline but it is somewhat
machine-dependent. Most workloads show little or not performance difference
implying that there is not a heavily reliance on the throttling mechanism
and it is safe to remove.
STREAM on 2-socket machine
4.19.0-rc5 4.19.0-rc5
numab-v1r1 noratelimit-v1r1
MB/sec copy 43298.52 ( 0.00%) 44673.38 ( 3.18%)
MB/sec scale 30115.06 ( 0.00%) 31293.06 ( 3.91%)
MB/sec add 32825.12 ( 0.00%) 34883.62 ( 6.27%)
MB/sec triad 32549.52 ( 0.00%) 34906.60 ( 7.24%
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Rik van Riel <riel@surriel.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jirka Hladky <jhladky@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Linux-MM <linux-mm@kvack.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20181001100525.29789-2-mgorman@techsingularity.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When scanning for movable pages, filter out Hugetlb pages if hugepage
migration is not supported. Without this we hit infinte loop in
__offline_pages() where we do
pfn = scan_movable_pages(start_pfn, end_pfn);
if (pfn) { /* We have movable pages */
ret = do_migrate_range(pfn, end_pfn);
goto repeat;
}
Fix this by checking hugepage_migration_supported both in
has_unmovable_pages which is the primary backoff mechanism for page
offlining and for consistency reasons also into scan_movable_pages
because it doesn't make any sense to return a pfn to non-migrateable
huge page.
This issue was revealed by, but not caused by 72b39cfc4d ("mm,
memory_hotplug: do not fail offlining too early").
Link: http://lkml.kernel.org/r/20180824063314.21981-1-aneesh.kumar@linux.ibm.com
Fixes: 72b39cfc4d ("mm, memory_hotplug: do not fail offlining too early")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reported-by: Haren Myneni <haren@linux.vnet.ibm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A process can be killed with SIGBUS(BUS_MCEERR_AR) when it tries to
allocate a page that was just freed on the way of soft-offline. This is
undesirable because soft-offline (which is about corrected error) is
less aggressive than hard-offline (which is about uncorrected error),
and we can make soft-offline fail and keep using the page for good
reason like "system is busy."
Two main changes of this patch are:
- setting migrate type of the target page to MIGRATE_ISOLATE. As done
in free_unref_page_commit(), this makes kernel bypass pcplist when
freeing the page. So we can assume that the page is in freelist just
after put_page() returns,
- setting PG_hwpoison on free page under zone->lock which protects
freelists, so this allows us to avoid setting PG_hwpoison on a page
that is decided to be allocated soon.
[akpm@linux-foundation.org: tweak set_hwpoison_free_buddy_page() comment]
Link: http://lkml.kernel.org/r/1531452366-11661-3-git-send-email-n-horiguchi@ah.jp.nec.com
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reported-by: Xishi Qiu <xishi.qiuxishi@alibaba-inc.com>
Tested-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <zy.zhengyi@alibaba-inc.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, whenever a new node is created/re-used from the memhotplug
path, we call free_area_init_node()->free_area_init_core(). But there is
some code that we do not really need to run when we are coming from such
path.
free_area_init_core() performs the following actions:
1) Initializes pgdat internals, such as spinlock, waitqueues and more.
2) Account # nr_all_pages and # nr_kernel_pages. These values are used later on
when creating hash tables.
3) Account number of managed_pages per zone, substracting dma_reserved and
memmap pages.
4) Initializes some fields of the zone structure data
5) Calls init_currently_empty_zone to initialize all the freelists
6) Calls memmap_init to initialize all pages belonging to certain zone
When called from memhotplug path, free_area_init_core() only performs
actions #1 and #4.
Action #2 is pointless as the zones do not have any pages since either the
node was freed, or we are re-using it, eitherway all zones belonging to
this node should have 0 pages. For the same reason, action #3 results
always in manages_pages being 0.
Action #5 and #6 are performed later on when onlining the pages:
online_pages()->move_pfn_range_to_zone()->init_currently_empty_zone()
online_pages()->move_pfn_range_to_zone()->memmap_init_zone()
This patch does two things:
First, moves the node/zone initializtion to their own function, so it
allows us to create a small version of free_area_init_core, where we only
perform:
1) Initialization of pgdat internals, such as spinlock, waitqueues and more
4) Initialization of some fields of the zone structure data
These two functions are: pgdat_init_internals() and zone_init_internals().
The second thing this patch does, is to introduce
free_area_init_core_hotplug(), the memhotplug version of
free_area_init_core():
Currently, we call free_area_init_node() from the memhotplug path. In
there, we set some pgdat's fields, and call calculate_node_totalpages().
calculate_node_totalpages() calculates the # of pages the node has.
Since the node is either new, or we are re-using it, the zones belonging
to this node should not have any pages, so there is no point to calculate
this now.
Actually, we re-set these values to 0 later on with the calls to:
reset_node_managed_pages()
reset_node_present_pages()
The # of pages per node and the # of pages per zone will be calculated when
onlining the pages:
online_pages()->move_pfn_range()->move_pfn_range_to_zone()->resize_zone_range()
online_pages()->move_pfn_range()->move_pfn_range_to_zone()->resize_pgdat_range()
Also, since free_area_init_core/free_area_init_node will now only get called during early init, let us replace
__paginginit with __init, so their code gets freed up.
[osalvador@techadventures.net: fix section usage]
Link: http://lkml.kernel.org/r/20180731101752.GA473@techadventures.net
[osalvador@suse.de: v6]
Link: http://lkml.kernel.org/r/20180801122348.21588-6-osalvador@techadventures.net
Link: http://lkml.kernel.org/r/20180730101757.28058-5-osalvador@techadventures.net
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Let us move the code between CONFIG_DEFERRED_STRUCT_PAGE_INIT to an inline
function. Not having an ifdef in the function makes the code more
readable.
Link: http://lkml.kernel.org/r/20180730101757.28058-4-osalvador@techadventures.net
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__paginginit is the same thing as __meminit except for platforms without
sparsemem, there it is defined as __init.
Remove __paginginit and use __meminit. Use __ref in one single function
that merges __meminit and __init sections: setup_usemap().
Link: http://lkml.kernel.org/r/20180801122348.21588-4-osalvador@techadventures.net
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
zone->node is configured only when CONFIG_NUMA=y, so it is a good idea to
have inline functions to access this field in order to avoid ifdef's in c
files.
Link: http://lkml.kernel.org/r/20180730101757.28058-3-osalvador@techadventures.net
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "Refactor free_area_init_core and add
free_area_init_core_hotplug", v6.
This patchset does three things:
1) Clean up/refactor free_area_init_core/free_area_init_node
by moving the ifdefery out of the functions.
2) Move the pgdat/zone initialization in free_area_init_core to its
own function.
3) Introduce free_area_init_core_hotplug, a small subset of
free_area_init_core, which is only called from memhotlug code path. In this
way, we have:
free_area_init_core: called during early initialization
free_area_init_core_hotplug: called whenever a new node is allocated/re-used (memhotplug path)
This patch (of 5):
Moving the #ifdefs out of the function makes it easier to follow.
Link: http://lkml.kernel.org/r/20180730101757.28058-2-osalvador@techadventures.net
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is no real reason to blow up just because the caller doesn't know
that __get_free_pages cannot return highmem pages. Simply fix that up
silently. Even if we have some confused users such a fixup will not be
harmful.
[akpm@linux-foundation.org: mask off __GFP_HIGHMEM]
Link: http://lkml.kernel.org/r/20180622162841.25114-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiankang Chen <chenjiankang1@huawei.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Yisheng Xie <xieyisheng1@huawei.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__alloc_pages_slowpath() has for a long time contained code to ignore
node restrictions from memory policies for high priority allocations.
The current code that resets the zonelist iterator however does
effectively nothing after commit 7810e6781e ("mm, page_alloc: do not
break __GFP_THISNODE by zonelist reset") removed a buggy zonelist reset.
Even before that commit, mempolicy restrictions were still not ignored,
as they are passed in ac->nodemask which is untouched by the code.
We can either remove the code, or make it work as intended. Since
ac->nodemask can be set from task's mempolicy via alloc_pages_current()
and thus also alloc_pages(), it may indeed affect kernel allocations,
and it makes sense to ignore it to allow progress for high priority
allocations.
Thus, this patch resets ac->nodemask to NULL in such cases. This
assumes all callers can handle it (i.e. there are no guarantees as in
the case of __GFP_THISNODE) which seems to be the case. The same
assumption is already present in check_retry_cpuset() for some time.
The expected effect is that high priority kernel allocations in the
context of userspace tasks (e.g. OOM victims) restricted by mempolicies
will have higher chance to succeed if they are restricted to nodes with
depleted memory, while there are other nodes with free memory left.
It's not a new intention, but for the first time the code will match the
intention, AFAICS. It was intended by commit 183f6371aa ("mm: ignore
mempolicies when using ALLOC_NO_WATERMARK") in v3.6 but I think it never
really worked, as mempolicy restriction was already encoded in nodemask,
not zonelist, at that time.
So originally that was for ALLOC_NO_WATERMARK only. Then it was
adjusted by e46e7b77c9 ("mm, page_alloc: recalculate the preferred
zoneref if the context can ignore memory policies") and cd04ae1e2d
("mm, oom: do not rely on TIF_MEMDIE for memory reserves access") to the
current state. So even GFP_ATOMIC would now ignore mempolicies after
the initial attempts fail - if the code worked as people thought it
does.
Link: http://lkml.kernel.org/r/20180612122624.8045-1-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The role of zero_resv_unavail() is to make sure that every struct page
that is allocated but is not backed by memory that is accessible by
kernel is zeroed and not in some uninitialized state.
Since struct pages are allocated in blocks (2M pages in x86 case), we
can skip pageblock_nr_pages at a time, when the first one is found to be
invalid.
This optimization may help since now on x86 every hole in e820 maps is
marked as reserved in memblock, and thus will go through this function.
This function is called before sched_clock() is initialized, so I used
my x86 early boot clock patches to measure the performance improvement.
With 1T hole on i7-8700 currently we would take 0.606918s of boot time,
but with this optimization 0.001103s.
Link: http://lkml.kernel.org/r/20180615155733.1175-1-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Add a new framework for CPU idle time injection (Daniel Lezcano).
- Add AVS support to the armada-37xx cpufreq driver (Gregory CLEMENT).
- Add support for current CPU frequency reporting to the ACPI CPPC
cpufreq driver (George Cherian).
- Rework the cooling device registration in the imx6q/thermal
driver (Bastian Stender).
- Make the pcc-cpufreq driver refuse to work with dynamic
scaling governors on systems with many CPUs to avoid
scalability issues with it (Rafael Wysocki).
- Fix the intel_pstate driver to report different maximum CPU
frequencies on systems where they really are different and to
ignore the turbo active ratio if hardware-managend P-states (HWP)
are in use; make it use the match_string() helper (Xie Yisheng,
Srinivas Pandruvada).
- Fix a minor deferred probe issue in the qcom-kryo cpufreq
driver (Niklas Cassel).
- Add a tracepoint for the tracking of frequency limits changes
(from Andriod) to the cpufreq core (Ruchi Kandoi).
- Fix a circular lock dependency between CPU hotplug and sysfs
locking in the cpufreq core reported by lockdep (Waiman Long).
- Avoid excessive error reports on driver registration failures
in the ARM cpuidle driver (Sudeep Holla).
- Add a new device links flag to the driver core to make links go
away automatically on supplier driver removal (Vivek Gautam).
- Eliminate potential race condition between system-wide power
management transitions and system shutdown (Pingfan Liu).
- Add a quirk to save NVS memory on system suspend for the ASUS
1025C laptop (Willy Tarreau).
- Make more systems use suspend-to-idle (instead of ACPI S3) by
default (Tristian Celestin).
- Get rid of stack VLA usage in the low-level hibernation code on
64-bit x86 (Kees Cook).
- Fix error handling in the hibernation core and mark an expected
fall-through switch in it (Chengguang Xu, Gustavo Silva).
- Extend the generic power domains (genpd) framework to support
attaching a device to a power domain by name (Ulf Hansson).
- Fix device reference counting and user limits initialization in
the devfreq core (Arvind Yadav, Matthias Kaehlcke).
- Fix a few issues in the rk3399_dmc devfreq driver and improve its
documentation (Enric Balletbo i Serra, Lin Huang, Nick Milner).
- Drop a redundant error message from the exynos-ppmu devfreq driver
(Markus Elfring).
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Merge tag 'pm-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management updates from Rafael Wysocki:
"These add a new framework for CPU idle time injection, to be used by
all of the idle injection code in the kernel in the future, fix some
issues and add a number of relatively small extensions in multiple
places.
Specifics:
- Add a new framework for CPU idle time injection (Daniel Lezcano).
- Add AVS support to the armada-37xx cpufreq driver (Gregory
CLEMENT).
- Add support for current CPU frequency reporting to the ACPI CPPC
cpufreq driver (George Cherian).
- Rework the cooling device registration in the imx6q/thermal driver
(Bastian Stender).
- Make the pcc-cpufreq driver refuse to work with dynamic scaling
governors on systems with many CPUs to avoid scalability issues
with it (Rafael Wysocki).
- Fix the intel_pstate driver to report different maximum CPU
frequencies on systems where they really are different and to
ignore the turbo active ratio if hardware-managend P-states (HWP)
are in use; make it use the match_string() helper (Xie Yisheng,
Srinivas Pandruvada).
- Fix a minor deferred probe issue in the qcom-kryo cpufreq driver
(Niklas Cassel).
- Add a tracepoint for the tracking of frequency limits changes (from
Andriod) to the cpufreq core (Ruchi Kandoi).
- Fix a circular lock dependency between CPU hotplug and sysfs
locking in the cpufreq core reported by lockdep (Waiman Long).
- Avoid excessive error reports on driver registration failures in
the ARM cpuidle driver (Sudeep Holla).
- Add a new device links flag to the driver core to make links go
away automatically on supplier driver removal (Vivek Gautam).
- Eliminate potential race condition between system-wide power
management transitions and system shutdown (Pingfan Liu).
- Add a quirk to save NVS memory on system suspend for the ASUS 1025C
laptop (Willy Tarreau).
- Make more systems use suspend-to-idle (instead of ACPI S3) by
default (Tristian Celestin).
- Get rid of stack VLA usage in the low-level hibernation code on
64-bit x86 (Kees Cook).
- Fix error handling in the hibernation core and mark an expected
fall-through switch in it (Chengguang Xu, Gustavo Silva).
- Extend the generic power domains (genpd) framework to support
attaching a device to a power domain by name (Ulf Hansson).
- Fix device reference counting and user limits initialization in the
devfreq core (Arvind Yadav, Matthias Kaehlcke).
- Fix a few issues in the rk3399_dmc devfreq driver and improve its
documentation (Enric Balletbo i Serra, Lin Huang, Nick Milner).
- Drop a redundant error message from the exynos-ppmu devfreq driver
(Markus Elfring)"
* tag 'pm-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (35 commits)
PM / reboot: Eliminate race between reboot and suspend
PM / hibernate: Mark expected switch fall-through
cpufreq: intel_pstate: Ignore turbo active ratio in HWP
cpufreq: Fix a circular lock dependency problem
cpu/hotplug: Add a cpus_read_trylock() function
x86/power/hibernate_64: Remove VLA usage
cpufreq: trace frequency limits change
cpufreq: intel_pstate: Show different max frequency with turbo 3 and HWP
cpufreq: pcc-cpufreq: Disable dynamic scaling on many-CPU systems
cpufreq: qcom-kryo: Silently error out on EPROBE_DEFER
cpufreq / CPPC: Add cpuinfo_cur_freq support for CPPC
cpufreq: armada-37xx: Add AVS support
dt-bindings: marvell: Add documentation for the Armada 3700 AVS binding
PM / devfreq: rk3399_dmc: Fix duplicated opp table on reload.
PM / devfreq: Init user limits from OPP limits, not viceversa
PM / devfreq: rk3399_dmc: fix spelling mistakes.
PM / devfreq: rk3399_dmc: do not print error when get supply and clk defer.
dt-bindings: devfreq: rk3399_dmc: move interrupts to be optional.
PM / devfreq: rk3399_dmc: remove wait for dcf irq event.
dt-bindings: clock: add rk3399 DDR3 standard speed bins.
...
Merge changes in the PM core, system-wide PM infrastructure, generic
power domains (genpd) framework, ACPI PM infrastructure and cpuidle
for 4.19.
* pm-core:
driver core: Add flag to autoremove device link on supplier unbind
driver core: Rename flag AUTOREMOVE to AUTOREMOVE_CONSUMER
* pm-domains:
PM / Domains: Introduce dev_pm_domain_attach_by_name()
PM / Domains: Introduce option to attach a device by name to genpd
PM / Domains: dt: Add a power-domain-names property
* pm-sleep:
PM / reboot: Eliminate race between reboot and suspend
PM / hibernate: Mark expected switch fall-through
x86/power/hibernate_64: Remove VLA usage
PM / hibernate: cast PAGE_SIZE to int when comparing with error code
* acpi-pm:
ACPI / PM: save NVS memory for ASUS 1025C laptop
ACPI / PM: Default to s2idle in all machines supporting LP S0
* pm-cpuidle:
ARM: cpuidle: silence error on driver registration failure
At present, "systemctl suspend" and "shutdown" can run in parrallel. A
system can suspend after devices_shutdown(), and resume. Then the shutdown
task goes on to power off. This causes many devices are not really shut
off. Hence replacing reboot_mutex with system_transition_mutex (renamed
from pm_mutex) to achieve the exclusion. The renaming of pm_mutex as
system_transition_mutex can be better to reflect the purpose of the mutex.
Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
free_reserved_area() takes pointers as arguments to show which addresses
should be freed. However, it does this in a somewhat ambiguous way. If it
gets a kernel direct map address, it always works. However, if it gets an
address that is part of the kernel image alias mapping, it can fail.
It fails if all of the following happen:
* The specified address is part of the kernel image alias
* Poisoning is requested (forcing a memset())
* The address is in a read-only portion of the kernel image
The memset() fails on the read-only mapping, of course.
free_reserved_area() *is* called both on the direct map and on kernel image
alias addresses. We've just lucked out thus far that the kernel image
alias areas it gets used on are read-write. I'm fairly sure this has been
just a happy accident.
It is quite easy to make free_reserved_area() work for all cases: just
convert the address to a direct map address before doing the memset(), and
do this unconditionally. There is little chance of a regression here
because we previously did a virt_to_page() on the address for the memset,
so we know these are not highmem pages for which virt_to_page() would fail.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: keescook@google.com
Cc: aarcange@redhat.com
Cc: jgross@suse.com
Cc: jpoimboe@redhat.com
Cc: gregkh@linuxfoundation.org
Cc: peterz@infradead.org
Cc: hughd@google.com
Cc: torvalds@linux-foundation.org
Cc: bp@alien8.de
Cc: luto@kernel.org
Cc: ak@linux.intel.com
Cc: Kees Cook <keescook@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Link: https://lkml.kernel.org/r/20180802225826.1287AE3E@viggo.jf.intel.com
Moving zero_resv_unavail before memmap_init_zone(), caused a regression on
x86-32.
The cause is that we access struct pages before they are allocated when
CONFIG_FLAT_NODE_MEM_MAP is used.
free_area_init_nodes()
zero_resv_unavail()
mm_zero_struct_page(pfn_to_page(pfn)); <- struct page is not alloced
free_area_init_node()
if CONFIG_FLAT_NODE_MEM_MAP
alloc_node_mem_map()
memblock_virt_alloc_node_nopanic() <- struct page alloced here
On the other hand memblock_virt_alloc_node_nopanic() zeroes all the memory
that it returns, so we do not need to do zero_resv_unavail() here.
Fixes: e181ae0c5d ("mm: zero unavailable pages before memmap init")
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Tested-by: Matt Hart <matt@mattface.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We must zero struct pages for memory that is not backed by physical
memory, or kernel does not have access to.
Recently, there was a change which zeroed all memmap for all holes in
e820. Unfortunately, it introduced a bug that is discussed here:
https://www.spinics.net/lists/linux-mm/msg156764.html
Linus, also saw this bug on his machine, and confirmed that reverting
commit 124049decb ("x86/e820: put !E820_TYPE_RAM regions into
memblock.reserved") fixes the issue.
The problem is that we incorrectly zero some struct pages after they
were setup.
The fix is to zero unavailable struct pages prior to initializing of
struct pages.
A more detailed fix should come later that would avoid double zeroing
cases: one in __init_single_page(), the other one in
zero_resv_unavail().
Fixes: 124049decb ("x86/e820: put !E820_TYPE_RAM regions into memblock.reserved")
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/*.c files use symbolic and octal styles for permissions.
Using octal and not symbolic permissions is preferred by many as more
readable.
https://lkml.org/lkml/2016/8/2/1945
Prefer the direct use of octal for permissions.
Done using
$ scripts/checkpatch.pl -f --types=SYMBOLIC_PERMS --fix-inplace mm/*.c
and some typing.
Before: $ git grep -P -w "0[0-7]{3,3}" mm | wc -l
44
After: $ git grep -P -w "0[0-7]{3,3}" mm | wc -l
86
Miscellanea:
o Whitespace neatening around these conversions.
Link: http://lkml.kernel.org/r/2e032ef111eebcd4c5952bae86763b541d373469.1522102887.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In __alloc_pages_slowpath() we reset zonelist and preferred_zoneref for
allocations that can ignore memory policies. The zonelist is obtained
from current CPU's node. This is a problem for __GFP_THISNODE
allocations that want to allocate on a different node, e.g. because the
allocating thread has been migrated to a different CPU.
This has been observed to break SLAB in our 4.4-based kernel, because
there it relies on __GFP_THISNODE working as intended. If a slab page
is put on wrong node's list, then further list manipulations may corrupt
the list because page_to_nid() is used to determine which node's
list_lock should be locked and thus we may take a wrong lock and race.
Current SLAB implementation seems to be immune by luck thanks to commit
511e3a0588 ("mm/slab: make cache_grow() handle the page allocated on
arbitrary node") but there may be others assuming that __GFP_THISNODE
works as promised.
We can fix it by simply removing the zonelist reset completely. There
is actually no reason to reset it, because memory policies and cpusets
don't affect the zonelist choice in the first place. This was different
when commit 183f6371aa ("mm: ignore mempolicies when using
ALLOC_NO_WATERMARK") introduced the code, as mempolicies provided their
own restricted zonelists.
We might consider this for 4.17 although I don't know if there's
anything currently broken.
SLAB is currently not affected, but in kernels older than 4.7 that don't
yet have 511e3a0588 ("mm/slab: make cache_grow() handle the page
allocated on arbitrary node") it is. That's at least 4.4 LTS. Older
ones I'll have to check.
So stable backports should be more important, but will have to be
reviewed carefully, as the code went through many changes. BTW I think
that also the ac->preferred_zoneref reset is currently useless if we
don't also reset ac->nodemask from a mempolicy to NULL first (which we
probably should for the OOM victims etc?), but I would leave that for a
separate patch.
Link: http://lkml.kernel.org/r/20180525130853.13915-1-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Fixes: 183f6371aa ("mm: ignore mempolicies when using ALLOC_NO_WATERMARK")
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This gives us five words of space in a single union in struct page. The
compound_mapcount moves position (from offset 24 to offset 20) on 64-bit
systems, but that does not seem likely to cause any trouble.
Link: http://lkml.kernel.org/r/20180518194519.3820-11-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that we can represent the location of 'deferred_list' in C instead of
comments, make use of that ability.
Link: http://lkml.kernel.org/r/20180518194519.3820-9-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We're already using a union of many fields here, so stop abusing the
_mapcount and make page_type its own field. That implies renaming some of
the machinery that creates PageBuddy, PageBalloon and PageKmemcg; bring
back the PG_buddy, PG_balloon and PG_kmemcg names.
As suggested by Kirill, make page_type a bitmask. Because it starts out
life as -1 (thanks to sharing the storage with _mapcount), setting a page
flag means clearing the appropriate bit. This gives us space for probably
twenty or so extra bits (depending how paranoid we want to be about
_mapcount underflow).
Link: http://lkml.kernel.org/r/20180518194519.3820-3-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
finalise_ac() has parameter order which is not used at all. Remove it.
Signed-off-by: Huaisheng Ye <yehs1@lenovo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
is_pageblock_removable_nolock() is not used outside of
mm/memory_hotplug.c. Move it next to unique caller
is_mem_section_removable() and make it static.
Remove prototype in <linux/memory_hotplug.h> to silence gcc warning (W=1):
mm/page_alloc.c:7704:6: warning: no previous prototype for `is_pageblock_removable_nolock' [-Wmissing-prototypes]
Link: http://lkml.kernel.org/r/20180509190001.24789-1-malat@debian.org
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Suggested-by: Michal Hocko <mhocko@kernel.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
While revisiting my Btrfs swapfile series [1], I introduced a situation
in which reclaim would lock i_rwsem, and even though the swapon() path
clearly made GFP_KERNEL allocations while holding i_rwsem, I got no
complaints from lockdep. It turns out that the rework of the fs_reclaim
annotation was broken: if the current task has PF_MEMALLOC set, we don't
acquire the dummy fs_reclaim lock, but when reclaiming we always check
this _after_ we've just set the PF_MEMALLOC flag. In most cases, we can
fix this by moving the fs_reclaim_{acquire,release}() outside of the
memalloc_noreclaim_{save,restore}(), althought kswapd is slightly
different. After applying this, I got the expected lockdep splats.
1: https://lwn.net/Articles/625412/
Link: http://lkml.kernel.org/r/9f8aa70652a98e98d7c4de0fc96a4addcee13efe.1523778026.git.osandov@fb.com
Fixes: d92a8cfcb3 ("locking/lockdep: Rework FS_RECLAIM annotation")
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Highmem's realsize always equals to freesize, so it is not necessary to
spare a variable to record this.
Link: http://lkml.kernel.org/r/20180413083859.65888-1-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oscar has reported:
: Due to an unfortunate setting with movablecore, memblocks containing bootmem
: memory (pages marked by get_page_bootmem()) ended up marked in zone_movable.
: So while trying to remove that memory, the system failed in do_migrate_range
: and __offline_pages never returned.
:
: This can be reproduced by running
: qemu-system-x86_64 -m 6G,slots=8,maxmem=8G -numa node,mem=4096M -numa node,mem=2048M
: and movablecore=4G kernel command line
:
: linux kernel: BIOS-provided physical RAM map:
: linux kernel: BIOS-e820: [mem 0x0000000000000000-0x000000000009fbff] usable
: linux kernel: BIOS-e820: [mem 0x000000000009fc00-0x000000000009ffff] reserved
: linux kernel: BIOS-e820: [mem 0x00000000000f0000-0x00000000000fffff] reserved
: linux kernel: BIOS-e820: [mem 0x0000000000100000-0x00000000bffdffff] usable
: linux kernel: BIOS-e820: [mem 0x00000000bffe0000-0x00000000bfffffff] reserved
: linux kernel: BIOS-e820: [mem 0x00000000feffc000-0x00000000feffffff] reserved
: linux kernel: BIOS-e820: [mem 0x00000000fffc0000-0x00000000ffffffff] reserved
: linux kernel: BIOS-e820: [mem 0x0000000100000000-0x00000001bfffffff] usable
: linux kernel: NX (Execute Disable) protection: active
: linux kernel: SMBIOS 2.8 present.
: linux kernel: DMI: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org
: linux kernel: Hypervisor detected: KVM
: linux kernel: e820: update [mem 0x00000000-0x00000fff] usable ==> reserved
: linux kernel: e820: remove [mem 0x000a0000-0x000fffff] usable
: linux kernel: last_pfn = 0x1c0000 max_arch_pfn = 0x400000000
:
: linux kernel: SRAT: PXM 0 -> APIC 0x00 -> Node 0
: linux kernel: SRAT: PXM 1 -> APIC 0x01 -> Node 1
: linux kernel: ACPI: SRAT: Node 0 PXM 0 [mem 0x00000000-0x0009ffff]
: linux kernel: ACPI: SRAT: Node 0 PXM 0 [mem 0x00100000-0xbfffffff]
: linux kernel: ACPI: SRAT: Node 0 PXM 0 [mem 0x100000000-0x13fffffff]
: linux kernel: ACPI: SRAT: Node 1 PXM 1 [mem 0x140000000-0x1bfffffff]
: linux kernel: ACPI: SRAT: Node 0 PXM 0 [mem 0x1c0000000-0x43fffffff] hotplug
: linux kernel: NUMA: Node 0 [mem 0x00000000-0x0009ffff] + [mem 0x00100000-0xbfffffff] -> [mem 0x0
: linux kernel: NUMA: Node 0 [mem 0x00000000-0xbfffffff] + [mem 0x100000000-0x13fffffff] -> [mem 0
: linux kernel: NODE_DATA(0) allocated [mem 0x13ffd6000-0x13fffffff]
: linux kernel: NODE_DATA(1) allocated [mem 0x1bffd3000-0x1bfffcfff]
:
: zoneinfo shows that the zone movable is placed into both numa nodes:
: Node 0, zone Movable
: pages free 160140
: min 1823
: low 2278
: high 2733
: spanned 262144
: present 262144
: managed 245670
: Node 1, zone Movable
: pages free 448427
: min 3827
: low 4783
: high 5739
: spanned 524288
: present 524288
: managed 515766
Note how only Node 0 has a hutplugable memory region which would rule it
out from the early memblock allocations (most likely memmap). Node1
will surely contain memmaps on the same node and those would prevent
offlining to succeed. So this is arguably a configuration issue.
Although one could argue that we should be more clever and rule early
allocations from the zone movable. This would be correct but probably
not worth the effort considering what a hack movablecore is.
Anyway, We could do better for those cases though. We rely on
start_isolate_page_range resp. has_unmovable_pages to do their job.
The first one isolates the whole range to be offlined so that we do not
allocate from it anymore and the later makes sure we are not stumbling
over non-migrateable pages.
has_unmovable_pages is overly optimistic, however. It doesn't check all
the pages if we are withing zone_movable because we rely that those
pages will be always migrateable. As it turns out we are still not
perfect there. While bootmem pages in zonemovable sound like a clear
bug which should be fixed let's remove the optimization for now and warn
if we encounter unmovable pages in zone_movable in the meantime. That
should help for now at least.
Btw. this wasn't a real problem until commit 72b39cfc4d ("mm,
memory_hotplug: do not fail offlining too early") because we used to
have a small number of retries and then failed. This turned out to be
too fragile though.
Link: http://lkml.kernel.org/r/20180523125555.30039-2-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Oscar Salvador <osalvador@techadventures.net>
Tested-by: Oscar Salvador <osalvador@techadventures.net>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts the following commits that change CMA design in MM.
3d2054ad8c ("ARM: CMA: avoid double mapping to the CMA area if CONFIG_HIGHMEM=y")
1d47a3ec09 ("mm/cma: remove ALLOC_CMA")
bad8c6c0b1 ("mm/cma: manage the memory of the CMA area by using the ZONE_MOVABLE")
Ville reported a following error on i386.
Inode-cache hash table entries: 65536 (order: 6, 262144 bytes)
microcode: microcode updated early to revision 0x4, date = 2013-06-28
Initializing CPU#0
Initializing HighMem for node 0 (000377fe:00118000)
Initializing Movable for node 0 (00000001:00118000)
BUG: Bad page state in process swapper pfn:377fe
page:f53effc0 count:0 mapcount:-127 mapping:00000000 index:0x0
flags: 0x80000000()
raw: 80000000 00000000 00000000 ffffff80 00000000 00000100 00000200 00000001
page dumped because: nonzero mapcount
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 4.17.0-rc5-elk+ #145
Hardware name: Dell Inc. Latitude E5410/03VXMC, BIOS A15 07/11/2013
Call Trace:
dump_stack+0x60/0x96
bad_page+0x9a/0x100
free_pages_check_bad+0x3f/0x60
free_pcppages_bulk+0x29d/0x5b0
free_unref_page_commit+0x84/0xb0
free_unref_page+0x3e/0x70
__free_pages+0x1d/0x20
free_highmem_page+0x19/0x40
add_highpages_with_active_regions+0xab/0xeb
set_highmem_pages_init+0x66/0x73
mem_init+0x1b/0x1d7
start_kernel+0x17a/0x363
i386_start_kernel+0x95/0x99
startup_32_smp+0x164/0x168
The reason for this error is that the span of MOVABLE_ZONE is extended
to whole node span for future CMA initialization, and, normal memory is
wrongly freed here. I submitted the fix and it seems to work, but,
another problem happened.
It's so late time to fix the later problem so I decide to reverting the
series.
Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Laura Abbott <labbott@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Juergen Gross noticed that commit f7f99100d8 ("mm: stop zeroing memory
during allocation in vmemmap") broke XEN PV domains when deferred struct
page initialization is enabled.
This is because the xen's PagePinned() flag is getting erased from
struct pages when they are initialized later in boot.
Juergen fixed this problem by disabling deferred pages on xen pv
domains. It is desirable, however, to have this feature available as it
reduces boot time. This fix re-enables the feature for pv-dmains, and
fixes the problem the following way:
The fix is to delay setting PagePinned flag until struct pages for all
allocated memory are initialized, i.e. until after free_all_bootmem().
A new x86_init.hyper op init_after_bootmem() is called to let xen know
that boot allocator is done, and hence struct pages for all the
allocated memory are now initialized. If deferred page initialization
is enabled, the rest of struct pages are going to be initialized later
in boot once page_alloc_init_late() is called.
xen_after_bootmem() walks page table's pages and marks them pinned.
Link: http://lkml.kernel.org/r/20180226160112.24724-2-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Juergen Gross <jgross@suse.com>
Tested-by: Juergen Gross <jgross@suse.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Mathias Krause <minipli@googlemail.com>
Cc: Jinbum Park <jinb.park7@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Jia Zhang <zhang.jia@linux.alibaba.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now, all reserved pages for CMA region are belong to the ZONE_MOVABLE
and it only serves for a request with GFP_HIGHMEM && GFP_MOVABLE.
Therefore, we don't need to maintain ALLOC_CMA at all.
Link: http://lkml.kernel.org/r/1512114786-5085-3-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm/cma: manage the memory of the CMA area by using the
ZONE_MOVABLE", v2.
0. History
This patchset is the follow-up of the discussion about the "Introduce
ZONE_CMA (v7)" [1]. Please reference it if more information is needed.
1. What does this patch do?
This patch changes the management way for the memory of the CMA area in
the MM subsystem. Currently the memory of the CMA area is managed by
the zone where their pfn is belong to. However, this approach has some
problems since MM subsystem doesn't have enough logic to handle the
situation that different characteristic memories are in a single zone.
To solve this issue, this patch try to manage all the memory of the CMA
area by using the MOVABLE zone. In MM subsystem's point of view,
characteristic of the memory on the MOVABLE zone and the memory of the
CMA area are the same. So, managing the memory of the CMA area by using
the MOVABLE zone will not have any problem.
2. Motivation
There are some problems with current approach. See following. Although
these problem would not be inherent and it could be fixed without this
conception change, it requires many hooks addition in various code path
and it would be intrusive to core MM and would be really error-prone.
Therefore, I try to solve them with this new approach. Anyway,
following is the problems of the current implementation.
o CMA memory utilization
First, following is the freepage calculation logic in MM.
- For movable allocation: freepage = total freepage
- For unmovable allocation: freepage = total freepage - CMA freepage
Freepages on the CMA area is used after the normal freepages in the zone
where the memory of the CMA area is belong to are exhausted. At that
moment that the number of the normal freepages is zero, so
- For movable allocation: freepage = total freepage = CMA freepage
- For unmovable allocation: freepage = 0
If unmovable allocation comes at this moment, allocation request would
fail to pass the watermark check and reclaim is started. After reclaim,
there would exist the normal freepages so freepages on the CMA areas
would not be used.
FYI, there is another attempt [2] trying to solve this problem in lkml.
And, as far as I know, Qualcomm also has out-of-tree solution for this
problem.
Useless reclaim:
There is no logic to distinguish CMA pages in the reclaim path. Hence,
CMA page is reclaimed even if the system just needs the page that can be
usable for the kernel allocation.
Atomic allocation failure:
This is also related to the fallback allocation policy for the memory of
the CMA area. Consider the situation that the number of the normal
freepages is *zero* since the bunch of the movable allocation requests
come. Kswapd would not be woken up due to following freepage
calculation logic.
- For movable allocation: freepage = total freepage = CMA freepage
If atomic unmovable allocation request comes at this moment, it would
fails due to following logic.
- For unmovable allocation: freepage = total freepage - CMA freepage = 0
It was reported by Aneesh [3].
Useless compaction:
Usual high-order allocation request is unmovable allocation request and
it cannot be served from the memory of the CMA area. In compaction,
migration scanner try to migrate the page in the CMA area and make
high-order page there. As mentioned above, it cannot be usable for the
unmovable allocation request so it's just waste.
3. Current approach and new approach
Current approach is that the memory of the CMA area is managed by the
zone where their pfn is belong to. However, these memory should be
distinguishable since they have a strong limitation. So, they are
marked as MIGRATE_CMA in pageblock flag and handled specially. However,
as mentioned in section 2, the MM subsystem doesn't have enough logic to
deal with this special pageblock so many problems raised.
New approach is that the memory of the CMA area is managed by the
MOVABLE zone. MM already have enough logic to deal with special zone
like as HIGHMEM and MOVABLE zone. So, managing the memory of the CMA
area by the MOVABLE zone just naturally work well because constraints
for the memory of the CMA area that the memory should always be
migratable is the same with the constraint for the MOVABLE zone.
There is one side-effect for the usability of the memory of the CMA
area. The use of MOVABLE zone is only allowed for a request with
GFP_HIGHMEM && GFP_MOVABLE so now the memory of the CMA area is also
only allowed for this gfp flag. Before this patchset, a request with
GFP_MOVABLE can use them. IMO, It would not be a big issue since most
of GFP_MOVABLE request also has GFP_HIGHMEM flag. For example, file
cache page and anonymous page. However, file cache page for blockdev
file is an exception. Request for it has no GFP_HIGHMEM flag. There is
pros and cons on this exception. In my experience, blockdev file cache
pages are one of the top reason that causes cma_alloc() to fail
temporarily. So, we can get more guarantee of cma_alloc() success by
discarding this case.
Note that there is no change in admin POV since this patchset is just
for internal implementation change in MM subsystem. Just one minor
difference for admin is that the memory stat for CMA area will be
printed in the MOVABLE zone. That's all.
4. Result
Following is the experimental result related to utilization problem.
8 CPUs, 1024 MB, VIRTUAL MACHINE
make -j16
<Before>
CMA area: 0 MB 512 MB
Elapsed-time: 92.4 186.5
pswpin: 82 18647
pswpout: 160 69839
<After>
CMA : 0 MB 512 MB
Elapsed-time: 93.1 93.4
pswpin: 84 46
pswpout: 183 92
akpm: "kernel test robot" reported a 26% improvement in
vm-scalability.throughput:
http://lkml.kernel.org/r/20180330012721.GA3845@yexl-desktop
[1]: lkml.kernel.org/r/1491880640-9944-1-git-send-email-iamjoonsoo.kim@lge.com
[2]: https://lkml.org/lkml/2014/10/15/623
[3]: http://www.spinics.net/lists/linux-mm/msg100562.html
Link: http://lkml.kernel.org/r/1512114786-5085-2-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Freepage on ZONE_HIGHMEM doesn't work for kernel memory so it's not that
important to reserve. When ZONE_MOVABLE is used, this problem would
theorectically cause to decrease usable memory for GFP_HIGHUSER_MOVABLE
allocation request which is mainly used for page cache and anon page
allocation. So, fix it by setting 0 to
sysctl_lowmem_reserve_ratio[ZONE_HIGHMEM].
And, defining sysctl_lowmem_reserve_ratio array by MAX_NR_ZONES - 1 size
makes code complex. For example, if there is highmem system, following
reserve ratio is activated for *NORMAL ZONE* which would be easyily
misleading people.
#ifdef CONFIG_HIGHMEM
32
#endif
This patch also fixes this situation by defining
sysctl_lowmem_reserve_ratio array by MAX_NR_ZONES and place "#ifdef" to
right place.
Link: http://lkml.kernel.org/r/1504672525-17915-1-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Tony Lindgren <tony@atomide.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Cc: <linux-api@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Adjust /proc/meminfo MemAvailable calculation by adding the amount of
indirectly reclaimable memory (rounded to the PAGE_SIZE).
Link: http://lkml.kernel.org/r/20180305133743.12746-4-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
start_isolate_page_range() is used to set the migrate type of a set of
pageblocks to MIGRATE_ISOLATE while attempting to start a migration
operation. It assumes that only one thread is calling it for the
specified range. This routine is used by CMA, memory hotplug and
gigantic huge pages. Each of these users synchronize access to the
range within their subsystem. However, two subsystems (CMA and gigantic
huge pages for example) could attempt operations on the same range. If
this happens, one thread may 'undo' the work another thread is doing.
This can result in pageblocks being incorrectly left marked as
MIGRATE_ISOLATE and therefore not available for page allocation.
What is ideally needed is a way to synchronize access to a set of
pageblocks that are undergoing isolation and migration. The only thing
we know about these pageblocks is that they are all in the same zone. A
per-node mutex is too coarse as we want to allow multiple operations on
different ranges within the same zone concurrently. Instead, we will
use the migration type of the pageblocks themselves as a form of
synchronization.
start_isolate_page_range sets the migration type on a set of page-
blocks going in order from the one associated with the smallest pfn to
the largest pfn. The zone lock is acquired to check and set the
migration type. When going through the list of pageblocks check if
MIGRATE_ISOLATE is already set. If so, this indicates another thread is
working on this pageblock. We know exactly which pageblocks we set, so
clean up by undo those and return -EBUSY.
This allows start_isolate_page_range to serve as a synchronization
mechanism and will allow for more general use of callers making use of
these interfaces. Update comments in alloc_contig_range to reflect this
new functionality.
Each CPU holds the associated zone lock to modify or examine the
migration type of a pageblock. And, it will only examine/update a
single pageblock per lock acquire/release cycle.
Link: http://lkml.kernel.org/r/20180309224731.16978-1-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kswapd will not wakeup if per-zone watermarks are not failing or if too
many previous attempts at background reclaim have failed.
This can be true if there is a lot of free memory available. For high-
order allocations, kswapd is responsible for waking up kcompactd for
background compaction. If the zone is not below its watermarks or
reclaim has recently failed (lots of free memory, nothing left to
reclaim), kcompactd does not get woken up.
When __GFP_DIRECT_RECLAIM is not allowed, allow kcompactd to still be
woken up even if kswapd will not reclaim. This allows high-order
allocations, such as thp, to still trigger background compaction even
when the zone has an abundance of free memory.
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1803111659420.209721@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When a page is freed back to the global pool, its buddy will be checked
to see if it's possible to do a merge. This requires accessing buddy's
page structure and that access could take a long time if it's cache
cold.
This patch adds a prefetch to the to-be-freed page's buddy outside of
zone->lock in hope of accessing buddy's page structure later under
zone->lock will be faster. Since we *always* do buddy merging and check
an order-0 page's buddy to try to merge it when it goes into the main
allocator, the cacheline will always come in, i.e. the prefetched data
will never be unused.
Normally, the number of prefetch will be pcp->batch(default=31 and has
an upper limit of (PAGE_SHIFT * 8)=96 on x86_64) but in the case of
pcp's pages get all drained, it will be pcp->count which has an upper
limit of pcp->high. pcp->high, although has a default value of 186
(pcp->batch=31 * 6), can be changed by user through
/proc/sys/vm/percpu_pagelist_fraction and there is no software upper
limit so could be large, like several thousand. For this reason, only
the first pcp->batch number of page's buddy structure is prefetched to
avoid excessive prefetching.
In the meantime, there are two concerns:
1. the prefetch could potentially evict existing cachelines, especially
for L1D cache since it is not huge
2. there is some additional instruction overhead, namely calculating
buddy pfn twice
For 1, it's hard to say, this microbenchmark though shows good result
but the actual benefit of this patch will be workload/CPU dependant;
For 2, since the calculation is a XOR on two local variables, it's
expected in many cases that cycles spent will be offset by reduced
memory latency later. This is especially true for NUMA machines where
multiple CPUs are contending on zone->lock and the most time consuming
part under zone->lock is the wait of 'struct page' cacheline of the
to-be-freed pages and their buddies.
Test with will-it-scale/page_fault1 full load:
kernel Broadwell(2S) Skylake(2S) Broadwell(4S) Skylake(4S)
v4.16-rc2+ 9034215 7971818 13667135 15677465
patch2/3 9536374 +5.6% 8314710 +4.3% 14070408 +3.0% 16675866 +6.4%
this patch 10180856 +6.8% 8506369 +2.3% 14756865 +4.9% 17325324 +3.9%
Note: this patch's performance improvement percent is against patch2/3.
(Changelog stolen from Dave Hansen and Mel Gorman's comments at
http://lkml.kernel.org/r/148a42d8-8306-2f2f-7f7c-86bc118f8ccd@intel.com)
[aaron.lu@intel.com: use helper function, avoid disordering pages]
Link: http://lkml.kernel.org/r/20180301062845.26038-4-aaron.lu@intel.com
Link: http://lkml.kernel.org/r/20180320113146.GB24737@intel.com
[aaron.lu@intel.com: v4]
Link: http://lkml.kernel.org/r/20180301062845.26038-4-aaron.lu@intel.com
Link: http://lkml.kernel.org/r/20180309082431.GB30868@intel.com
Link: http://lkml.kernel.org/r/20180301062845.26038-4-aaron.lu@intel.com
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Suggested-by: Ying Huang <ying.huang@intel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Kemi Wang <kemi.wang@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When freeing a batch of pages from Per-CPU-Pages(PCP) back to buddy, the
zone->lock is held and then pages are chosen from PCP's migratetype
list. While there is actually no need to do this 'choose part' under
lock since it's PCP pages, the only CPU that can touch them is us and
irq is also disabled.
Moving this part outside could reduce lock held time and improve
performance. Test with will-it-scale/page_fault1 full load:
kernel Broadwell(2S) Skylake(2S) Broadwell(4S) Skylake(4S)
v4.16-rc2+ 9034215 7971818 13667135 15677465
this patch 9536374 +5.6% 8314710 +4.3% 14070408 +3.0% 16675866 +6.4%
What the test does is: starts $nr_cpu processes and each will repeatedly
do the following for 5 minutes:
- mmap 128M anonymouse space
- write access to that space
- munmap.
The score is the aggregated iteration.
https://github.com/antonblanchard/will-it-scale/blob/master/tests/page_fault1.c
Link: http://lkml.kernel.org/r/20180301062845.26038-3-aaron.lu@intel.com
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Kemi Wang <kemi.wang@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Matthew Wilcox found that all callers of free_pcppages_bulk() currently
update pcp->count immediately after so it's natural to do it inside
free_pcppages_bulk().
No functionality or performance change is expected from this patch.
Link: http://lkml.kernel.org/r/20180301062845.26038-2-aaron.lu@intel.com
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kemi Wang <kemi.wang@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mirrored_kernelcore can be in __meminitdata, so move it there.
At the same time, fixup section specifiers to be after the name of the
variable per checkpatch.
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1802121623280.179479@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Both kernelcore= and movablecore= can be used to define the amount of
ZONE_NORMAL and ZONE_MOVABLE on a system, respectively. This requires
the system memory capacity to be known when specifying the command line,
however.
This introduces the ability to define both kernelcore= and movablecore=
as a percentage of total system memory. This is convenient for systems
software that wants to define the amount of ZONE_MOVABLE, for example,
as a proportion of a system's memory rather than a hardcoded byte value.
To define the percentage, the final character of the parameter should be
a '%'.
mhocko: "why is anyone using these options nowadays?"
rientjes:
:
: Fragmentation of non-__GFP_MOVABLE pages due to low on memory
: situations can pollute most pageblocks on the system, as much as 1GB of
: slab being fragmented over 128GB of memory, for example. When the
: amount of kernel memory is well bounded for certain systems, it is
: better to aggressively reclaim from existing MIGRATE_UNMOVABLE
: pageblocks rather than eagerly fallback to others.
:
: We have additional patches that help with this fragmentation if you're
: interested, specifically kcompactd compaction of MIGRATE_UNMOVABLE
: pageblocks triggered by fallback of non-__GFP_MOVABLE allocations and
: draining of pcp lists back to the zone free area to prevent stranding.
[rientjes@google.com: updates]
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1802131700160.71590@chino.kir.corp.google.com
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1802121622470.179479@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
During memory hotplugging we traverse struct pages three times:
1. memset(0) in sparse_add_one_section()
2. loop in __add_section() to set do: set_page_node(page, nid); and
SetPageReserved(page);
3. loop in memmap_init_zone() to call __init_single_pfn()
This patch removes the first two loops, and leaves only loop 3. All
struct pages are initialized in one place, the same as it is done during
boot.
The benefits:
- We improve memory hotplug performance because we are not evicting the
cache several times and also reduce loop branching overhead.
- Remove condition from hotpath in __init_single_pfn(), that was added
in order to fix the problem that was reported by Bharata in the above
email thread, thus also improve performance during normal boot.
- Make memory hotplug more similar to the boot memory initialization
path because we zero and initialize struct pages only in one
function.
- Simplifies memory hotplug struct page initialization code, and thus
enables future improvements, such as multi-threading the
initialization of struct pages in order to improve hotplug
performance even further on larger machines.
[pasha.tatashin@oracle.com: v5]
Link: http://lkml.kernel.org/r/20180228030308.1116-7-pasha.tatashin@oracle.com
Link: http://lkml.kernel.org/r/20180215165920.8570-7-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Bharata B Rao <bharata@linux.vnet.ibm.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Deferred page initialization allows the boot cpu to initialize a small
subset of the system's pages early in boot, with other cpus doing the
rest later on.
It is, however, problematic to know how many pages the kernel needs
during boot. Different modules and kernel parameters may change the
requirement, so the boot cpu either initializes too many pages or runs
out of memory.
To fix that, initialize early pages on demand. This ensures the kernel
does the minimum amount of work to initialize pages during boot and
leaves the rest to be divided in the multithreaded initialization path
(deferred_init_memmap).
The on-demand code is permanently disabled using static branching once
deferred pages are initialized. After the static branch is changed to
false, the overhead is up-to two branch-always instructions if the zone
watermark check fails or if rmqueue fails.
Sergey Senozhatsky noticed that while deferred pages currently make
sense only on NUMA machines (we start one thread per latency node),
CONFIG_NUMA is not a requirement for CONFIG_DEFERRED_STRUCT_PAGE_INIT,
so that is also must be addressed in the patch.
[akpm@linux-foundation.org: fix typo in comment, make deferred_pages static]
[pasha.tatashin@oracle.com: fix min() type mismatch warning]
Link: http://lkml.kernel.org/r/20180212164543.26592-1-pasha.tatashin@oracle.com
[pasha.tatashin@oracle.com: use zone_to_nid() in deferred_grow_zone()]
Link: http://lkml.kernel.org/r/20180214163343.21234-2-pasha.tatashin@oracle.com
[pasha.tatashin@oracle.com: might_sleep warning]
Link: http://lkml.kernel.org/r/20180306192022.28289-1-pasha.tatashin@oracle.com
[akpm@linux-foundation.org: s/spin_lock/spin_lock_irq/ in page_alloc_init_late()]
[pasha.tatashin@oracle.com: v5]
Link: http://lkml.kernel.org/r/20180309220807.24961-3-pasha.tatashin@oracle.com
[akpm@linux-foundation.org: tweak comments]
[pasha.tatashin@oracle.com: v6]
Link: http://lkml.kernel.org/r/20180313182355.17669-3-pasha.tatashin@oracle.com
[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20180209192216.20509-2-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Steven Sistare <steven.sistare@oracle.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Gioh Kim <gi-oh.kim@profitbricks.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Miles Chen <miles.chen@mediatek.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vlastimil Babka reported about a window issue during which when deferred
pages are initialized, and the current version of on-demand
initialization is finished, allocations may fail. While this is highly
unlikely scenario, since this kind of allocation request must be large,
and must come from interrupt handler, we still want to cover it.
We solve this by initializing deferred pages with interrupts disabled,
and holding node_size_lock spin lock while pages in the node are being
initialized. The on-demand deferred page initialization that comes
later will use the same lock, and thus synchronize with
deferred_init_memmap().
It is unlikely for threads that initialize deferred pages to be
interrupted. They run soon after smp_init(), but before modules are
initialized, and long before user space programs. This is why there is
no adverse effect of having these threads running with interrupts
disabled.
[pasha.tatashin@oracle.com: v6]
Link: http://lkml.kernel.org/r/20180313182355.17669-2-pasha.tatashin@oracle.com
Link: http://lkml.kernel.org/r/20180309220807.24961-2-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Gioh Kim <gi-oh.kim@profitbricks.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Miles Chen <miles.chen@mediatek.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds
Vlastimil Babka
David Hildenbrand
Maninder Singh
Chen Tao
Daniel Jordan
Pavel Tatashin
Anshuman Khandual
Charan Teja Reddy
Sandipan Das
Wei Yang
Joonsoo Kim
Baoquan He
Roman Gushchin
Mike Rapoport
Christoph Hellwig
NeilBrown
David S. Miller
Sami Tolvanen
Henry Willard
Jason Yan
Randy Dunlap
Alexander Duyck
Rik van Riel
chenqiwu
Mateusz Nosek
Joel Savitz
John Hubbard
Aneesh Kumar K.V
Qian Cai
Kirill A. Shutemov
Johannes Weiner
lijiazi
Mel Gorman
David Rientjes
Yang Shi
Matthew Wilcox (Oracle)
Matt Fleming
Dan Williams
Yafang Shao
Alexander Potapenko
Nicholas Piggin
Denis Efremov
Juergen Gross
Thomas Gleixner
Baruch Siach
Michal Hocko
Linxu Fang
Alexandre Ghiti
Rick Edgecombe
Andrey Ryabinin
Alexey Dobriyan
Greg Kroah-Hartman
Shakeel Butt
Arun KS
Jann Horn
Benjamin Poirier
Waiman Long
Pingfan Liu
Oscar Salvador
yuzhoujian
Aaron Lu
Huang Shijie
Andrey Konovalov
Mikhail Zaslonko
Mike Rapoport
Pavel Tatashin
Naoya Horiguchi
Pavel Tatashin
Srikar Dronamraju
Mukesh Ojha
Rafael J. Wysocki
Dave Hansen
Joe Perches
Matthew Wilcox
Huaisheng Ye
Mathieu Malaterre
Omar Sandoval
Mike Kravetz