Граф коммитов

1720 Коммитов

Автор SHA1 Сообщение Дата
Adrian Bunk ec05b297f9 [PATCH] remove mm/filemap.c:file_send_actor()
This patch removes the no longer used file_send_actor().

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-08-11 22:34:47 +02:00
Christoph Lameter 1ceef40249 SLUB: Fix dynamic dma kmalloc cache creation
The dynamic dma kmalloc creation can run into trouble if a
GFP_ATOMIC allocation is the first one performed for a certain size
of dma kmalloc slab.

- Move the adding of the slab to sysfs into a workqueue
  (sysfs does GFP_KERNEL allocations)
- Do not call kmem_cache_destroy() (uses slub_lock)
- Only acquire the slub_lock once and--if we cannot wait--do a trylock.

  This introduces a slight risk of the first kmalloc(x, GFP_DMA|GFP_ATOMIC)
  for a range of sizes failing due to another process holding the slub_lock.
  However, we only need to acquire the spinlock once in order to establish
  each power of two DMA kmalloc cache. The possible conflict is with the
  slub_lock taken during slab management actions (create / remove slab cache).

  It is rather typical that a driver will first fill its buffers using
  GFP_KERNEL allocations which will wait until the slub_lock can be acquired.
  Drivers will also create its slab caches first outside of an atomic
  context before starting to use atomic kmalloc from an interrupt context.

  If there are any failures then they will occur early after boot or when
  loading of multiple drivers concurrently. Drivers can already accomodate
  failures of GFP_ATOMIC for other reasons. Retries will then create the slab.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
2007-08-09 21:57:16 -07:00
Christoph Lameter fcda3d89bf SLUB: Remove checks for MAX_PARTIAL from kmem_cache_shrink
The MAX_PARTIAL checks were supposed to be an optimization. However, slab
shrinking is a manually triggered process either through running slabinfo
or by the kernel calling kmem_cache_shrink.

If one really wants to shrink a slab then all operations should be done
regardless of the size of the partial list. This also fixes an issue that
could surface if the number of partial slabs was initially above MAX_PARTIAL
in kmem_cache_shrink and later drops below MAX_PARTIAL through the
elimination of empty slabs on the partial list (rare). In that case a few
slabs may be left off the partial list (and only be put back when they
are empty).

Signed-off-by: Christoph Lameter <clameter@sgi.com>
2007-08-09 21:57:15 -07:00
Randy Dunlap bfe0d6867e fix filemap.c kernel-doc
Fix kernel-doc warning:
Warning(linux-2.6.23-rc1-mm1//mm/filemap.c:864): No description found for parameter 'ra'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-31 15:39:38 -07:00
David Rientjes a5e58a6142 oom: print points as unsigned long
In badness(), the automatic variable 'points' is unsigned long.  Print it
as such.

Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-31 15:39:36 -07:00
Mel Gorman a8bbf72ab9 Do not trigger OOM-killer for high-order allocation failures
out_of_memory() may be called when an allocation is failing and the direct
reclaim is not making any progress.  This does not take into account the
requested order of the allocation.  If the request if for an order larger
than PAGE_ALLOC_COSTLY_ORDER, it is reasonable to fail the allocation
because the kernel makes no guarantees about those allocations succeeding.

This false OOM situation can occur if a user is trying to grow the hugepage
pool in a script like;

#!/bin/bash
REQUIRED=$1
echo 1 > /proc/sys/vm/hugepages_treat_as_movable
echo $REQUIRED > /proc/sys/vm/nr_hugepages
ACTUAL=`cat /proc/sys/vm/nr_hugepages`
while [ $REQUIRED -ne $ACTUAL ]; do
	echo Huge page pool at $ACTUAL growing to $REQUIRED
	echo $REQUIRED > /proc/sys/vm/nr_hugepages
	ACTUAL=`cat /proc/sys/vm/nr_hugepages`
	sleep 1
done

This is a reasonable scenario when ZONE_MOVABLE is in use but triggers OOM
easily on 2.6.23-rc1. This patch will fail an allocation for an order above
PAGE_ALLOC_COSTLY_ORDER instead of killing processes and retrying.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Andy Whitcroft <apw@shadowen.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-31 15:39:36 -07:00
Peter Zijlstra 2208b764c1 slub: fix bug in slub debug support
We ClearSlabDebug() before the last SlabDebug() check. Clear it later.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
2007-07-30 12:15:15 -07:00
Peter Zijlstra 02febdf7f6 slub: add lock debugging check
Ingo noticed that the SLUB code does include the lock debugging free
check.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
2007-07-30 12:12:39 -07:00
Alexey Dobriyan 4e950f6f01 Remove fs.h from mm.h
Remove fs.h from mm.h. For this,
 1) Uninline vma_wants_writenotify(). It's pretty huge anyway.
 2) Add back fs.h or less bloated headers (err.h) to files that need it.

As result, on x86_64 allyesconfig, fs.h dependencies cut down from 3929 files
rebuilt down to 3444 (-12.3%).

Cross-compile tested without regressions on my two usual configs and (sigh):

alpha              arm-mx1ads        mips-bigsur          powerpc-ebony
alpha-allnoconfig  arm-neponset      mips-capcella        powerpc-g5
alpha-defconfig    arm-netwinder     mips-cobalt          powerpc-holly
alpha-up           arm-netx          mips-db1000          powerpc-iseries
arm                arm-ns9xxx        mips-db1100          powerpc-linkstation
arm-assabet        arm-omap_h2_1610  mips-db1200          powerpc-lite5200
arm-at91rm9200dk   arm-onearm        mips-db1500          powerpc-maple
arm-at91rm9200ek   arm-picotux200    mips-db1550          powerpc-mpc7448_hpc2
arm-at91sam9260ek  arm-pleb          mips-ddb5477         powerpc-mpc8272_ads
arm-at91sam9261ek  arm-pnx4008       mips-decstation      powerpc-mpc8313_rdb
arm-at91sam9263ek  arm-pxa255-idp    mips-e55             powerpc-mpc832x_mds
arm-at91sam9rlek   arm-realview      mips-emma2rh         powerpc-mpc832x_rdb
arm-ateb9200       arm-realview-smp  mips-excite          powerpc-mpc834x_itx
arm-badge4         arm-rpc           mips-fulong          powerpc-mpc834x_itxgp
arm-carmeva        arm-s3c2410       mips-ip22            powerpc-mpc834x_mds
arm-cerfcube       arm-shannon       mips-ip27            powerpc-mpc836x_mds
arm-clps7500       arm-shark         mips-ip32            powerpc-mpc8540_ads
arm-collie         arm-simpad        mips-jazz            powerpc-mpc8544_ds
arm-corgi          arm-spitz         mips-jmr3927         powerpc-mpc8560_ads
arm-csb337         arm-trizeps4      mips-malta           powerpc-mpc8568mds
arm-csb637         arm-versatile     mips-mipssim         powerpc-mpc85xx_cds
arm-ebsa110        i386              mips-mpc30x          powerpc-mpc8641_hpcn
arm-edb7211        i386-allnoconfig  mips-msp71xx         powerpc-mpc866_ads
arm-em_x270        i386-defconfig    mips-ocelot          powerpc-mpc885_ads
arm-ep93xx         i386-up           mips-pb1100          powerpc-pasemi
arm-footbridge     ia64              mips-pb1500          powerpc-pmac32
arm-fortunet       ia64-allnoconfig  mips-pb1550          powerpc-ppc64
arm-h3600          ia64-bigsur       mips-pnx8550-jbs     powerpc-prpmc2800
arm-h7201          ia64-defconfig    mips-pnx8550-stb810  powerpc-ps3
arm-h7202          ia64-gensparse    mips-qemu            powerpc-pseries
arm-hackkit        ia64-sim          mips-rbhma4200       powerpc-up
arm-integrator     ia64-sn2          mips-rbhma4500       s390
arm-iop13xx        ia64-tiger        mips-rm200           s390-allnoconfig
arm-iop32x         ia64-up           mips-sb1250-swarm    s390-defconfig
arm-iop33x         ia64-zx1          mips-sead            s390-up
arm-ixp2000        m68k              mips-tb0219          sparc
arm-ixp23xx        m68k-amiga        mips-tb0226          sparc-allnoconfig
arm-ixp4xx         m68k-apollo       mips-tb0287          sparc-defconfig
arm-jornada720     m68k-atari        mips-workpad         sparc-up
arm-kafa           m68k-bvme6000     mips-wrppmc          sparc64
arm-kb9202         m68k-hp300        mips-yosemite        sparc64-allnoconfig
arm-ks8695         m68k-mac          parisc               sparc64-defconfig
arm-lart           m68k-mvme147      parisc-allnoconfig   sparc64-up
arm-lpd270         m68k-mvme16x      parisc-defconfig     um-x86_64
arm-lpd7a400       m68k-q40          parisc-up            x86_64
arm-lpd7a404       m68k-sun3         powerpc              x86_64-allnoconfig
arm-lubbock        m68k-sun3x        powerpc-cell         x86_64-defconfig
arm-lusl7200       mips              powerpc-celleb       x86_64-up
arm-mainstone      mips-atlas        powerpc-chrp32

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-29 17:09:29 -07:00
Rafael J. Wysocki 296699de6b Introduce CONFIG_SUSPEND for suspend-to-Ram and standby
Introduce CONFIG_SUSPEND representing the ability to enter system sleep
states, such as the ACPI S3 state, and allow the user to choose SUSPEND
and HIBERNATION independently of each other.

Make HOTPLUG_CPU be selected automatically if SUSPEND or HIBERNATION has
been chosen and the kernel is intended for SMP systems.

Also, introduce CONFIG_PM_SLEEP which is automatically selected if
CONFIG_SUSPEND or CONFIG_HIBERNATION is set and use it to select the
code needed for both suspend and hibernation.

The top-level power management headers and the ACPI code related to
suspend and hibernation are modified to use the new definitions (the
changes in drivers/acpi/sleep/main.c are, mostly, moving code to reduce
the number of ifdefs).

There are many other files in which CONFIG_PM can be replaced with
CONFIG_PM_SLEEP or even with CONFIG_SUSPEND, but they can be updated in
the future.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-29 16:45:38 -07:00
Rafael J. Wysocki b0cb1a19d0 Replace CONFIG_SOFTWARE_SUSPEND with CONFIG_HIBERNATION
Replace CONFIG_SOFTWARE_SUSPEND with CONFIG_HIBERNATION to avoid
confusion (among other things, with CONFIG_SUSPEND introduced in the
next patch).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-29 16:45:38 -07:00
Mel Gorman b5445f956e Allow nodes to exist that only contain ZONE_MOVABLE
With the introduction of kernelcore=, a configurable zone is created on
request.  In some cases, this value will be small enough that some nodes
contain only ZONE_MOVABLE.  On some NUMA configurations when this occurs,
arch-independent zone-sizing will get the size of the memory holes within
the node incorrect.  The value of present_pages goes negative and the boot
fails.

This patch fixes the bug in the calculation of the size of the hole.  The
test case is to boot test a NUMA machine with a low value of kernelcore=
before and after the patch is applied.  While this bug exists in early
kernel it cannot be triggered in practice.

This patch has been boot-tested on a variety machines with and without
kernelcore= set.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-26 11:35:19 -07:00
KAMEZAWA Hiroyuki 3dd9fe8c39 memory unplug: isolate_lru_page fix
release_pages() in mm/swap.c changes page_count() to be 0 without removing
PageLRU flag...

This means isolate_lru_page() can see a page, PageLRU() &&
page_count(page)==0..  This is BUG.  (get_page() will be called against
count=0 page.)

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-26 11:35:17 -07:00
KAMEZAWA Hiroyuki dc386d4d1e memory unplug: migration by kernel
In usual, migrate_pages(page,,) is called with holding mm->sem by system call.
(mm here is a mm_struct which maps the migration target page.)
This semaphore helps avoiding some race conditions.

But, if we want to migrate a page by some kernel codes, we have to avoid
some races. This patch adds check code for following race condition.

1. A page which page->mapping==NULL can be target of migration. Then, we have
   to check page->mapping before calling try_to_unmap().

2. anon_vma can be freed while page is unmapped, but page->mapping remains as
   it was. We drop page->mapcount to be 0. Then we cannot trust page->mapping.
   So, use rcu_read_lock() to prevent anon_vma pointed by page->mapping from
   being freed during migration.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-26 11:35:17 -07:00
Linus Torvalds b2e961eb2e Merge branch 'request-queue-t' of git://git.kernel.dk/linux-2.6-block
* 'request-queue-t' of git://git.kernel.dk/linux-2.6-block:
  [BLOCK] Add request_queue_t and mark it deprecated
  [BLOCK] Get rid of request_queue_t typedef
2007-07-24 12:26:44 -07:00
Andrew Morton b8c1c5da15 slab: correctly handle __GFP_ZERO
Use the correct local variable when calling into the page allocator.  Local
`flags' can have __GFP_ZERO set, which causes us to pass __GFP_ZERO into the
page allocator, possibly from illegal contexts.  The page allocator will later
do prep_zero_page()->kmap_atomic(..., KM_USER0) from irq contexts and will
then go BUG.

Cc: Mike Galbraith <efault@gmx.de>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-24 12:24:59 -07:00
Ken Chen 5ab3ee7b1c fix hugetlb page allocation leak
dequeue_huge_page() has a serious memory leak upon hugetlb page
allocation.  The for loop continues on allocating hugetlb pages out of
all allowable zone, where this function is supposedly only dequeue one
and only one pages.

Fixed it by breaking out of the for loop once a hugetlb page is found.

Signed-off-by: Ken Chen <kenchen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-24 12:24:59 -07:00
Jens Axboe 165125e1e4 [BLOCK] Get rid of request_queue_t typedef
Some of the code has been gradually transitioned to using the proper
struct request_queue, but there's lots left. So do a full sweet of
the kernel and get rid of this typedef and replace its uses with
the proper type.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-07-24 09:28:11 +02:00
Sam Ravnborg dec2e6b7aa x86_64: fix section mismatch warning in init.c
Fix following warning:
WARNING: vmlinux.o(.text+0x188ea): Section mismatch: reference to .init.text:__alloc_bootmem_core (between 'alloc_bootmem_high_node' and 'get_gate_vma')

alloc_bootmem_high_node() is only used from __init scope so declare it __init.
And in addition declare the weak variant __init too.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-22 11:03:38 -07:00
Matt Mackall d6269543ef slob: reduce list scanning
The version of SLOB in -mm always scans its free list from the beginning,
which results in small allocations and free segments clustering at the
beginning of the list over time.  This causes the average search to scan
over a large stretch at the beginning on each allocation.

By starting each page search where the last one left off, we evenly
distribute the allocations and greatly shorten the average search.

Without this patch, kernel compiles on a 1.5G machine take a large amount
of system time for list scanning.  With this patch, compiles are within a
few seconds of performance of a SLAB kernel with no notable change in
system time.

Signed-off-by: Matt Mackall <mpm@selenic.com>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-21 17:49:16 -07:00
Christoph Hellwig 41f9dc5c87 remove handle_mm_fault export
Now that arch/powerpc/platforms/cell/spufs/fault.c is always built in
the kernel there is no need to export handle_mm_fault anymore.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-21 17:49:16 -07:00
Paul Mundt b50731732f nommu: vmalloc_32_user()/vm_insert_page() and symbol exports.
Trying to survive an allmodconfig on a nommu platform results in many
screen lengths of module unhappiness.  Many of the mmap related things that
binfmt_flat hooks in to are never exported despite being global, and there
are also missing definitions for vmalloc_32_user() and vm_insert_page().

I've implemented vmalloc_32_user() trying to stick as close to the
mm/vmalloc.c implementation as possible, though we don't have any need for
VM_USERMAP, so groveling for the VMA can be skipped.  vm_insert_page() has
been stubbed for now in order to keep the build happy.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-21 17:49:14 -07:00
Paul Mundt e228929bc2 mm: fix memory hotplug oops from ZONE_MOVABLE changes.
zone_movable_pfn is presently marked as __initdata and referenced from
adjust_zone_range_for_zone_movable(), which in turn is referenced by
zone_spanned_pages_in_node().  Both of these are __meminit annotated.  When
memory hotplug is enabled, this will oops on a hot-add, due to
zone_movable_pfn having been freed.

__meminitdata annotation gives the desired behaviour.

This will only impact platforms that enable both memory hotplug
and ARCH_POPULATES_NODE_MAP.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-20 08:44:19 -07:00
Paul Mundt 20c2df83d2 mm: Remove slab destructors from kmem_cache_create().
Slab destructors were no longer supported after Christoph's
c59def9f22 change. They've been
BUGs for both slab and slub, and slob never supported them
either.

This rips out support for the dtor pointer from kmem_cache_create()
completely and fixes up every single callsite in the kernel (there were
about 224, not including the slab allocator definitions themselves,
or the documentation references).

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-07-20 10:11:58 +09:00
Linus Torvalds 9550b105b8 slub: fix ksize() for zero-sized pointers
The slab and slob allocators already did this right, but slub would call
"get_object_page()" on the magic ZERO_SIZE_PTR, with all kinds of nasty
end results.

Noted by Ingo Molnar.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 13:21:34 -07:00
Linus Torvalds a5c96d8a1c Fix up non-NUMA SLAB configuration for zero-sized allocations
I suspect Christoph tested his code only in the NUMA configuration, for
the combination of SLAB+non-NUMA the zero-sized kmalloc's would not work.

Of course, this would only trigger in configurations where those zero-
sized allocations happen (not very common), so that may explain why it
wasn't more widely noticed.

Seen by by Andi Kleen under qemu, and there seems to be a report by
Michael Tsirkin on it too.

Cc: Andi Kleen <ak@suse.de>
Cc: Roland Dreier <rdreier@cisco.com>
Cc: Michael S. Tsirkin <mst@dev.mellanox.co.il>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 13:17:15 -07:00
Rusty Russell 5992b6dac0 lguest: export symbols for lguest as a module
lguest does some fairly lowlevel things to support a host, which
normal modules don't need:

math_state_restore:
	When the guest triggers a Device Not Available fault, we need
	to be able to restore the FPU

__put_task_struct:
	We need to hold a reference to another task for inter-guest
	I/O, and put_task_struct() is an inline function which calls
	__put_task_struct.

access_process_vm:
	We need to access another task for inter-guest I/O.

map_vm_area & __get_vm_area:
	We need to map the switcher shim (ie. monitor) at 0xFFC01000.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:52 -07:00
Andrew Morton d688abf50b move page writeback acounting out of macros
page-writeback accounting is presently performed in the page-flags macros.
This is inconsistent and a bit ugly and makes it awkward to implement
per-backing_dev under-writeback page accounting.

So move this accounting down to the callsite(s).

Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:52 -07:00
Akinobu Mita f8af0bb890 hugetlb: use set_compound_page_dtor
Use appropriate accessor function to set compound page destructor
function.

Cc:  William Irwin <wli@holomorphy.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Adam Litke <agl@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:50 -07:00
Hugh Dickins 7ed5cb2b73 Remove nid_lock from alloc_fresh_huge_page
The fix to that race in alloc_fresh_huge_page() which could give an illegal
node ID did not need nid_lock at all: the fix was to replace static int nid
by static int prev_nid and do the work on local int nid.  nid_lock did make
sure that racers strictly roundrobin the nodes, but that's not something we
need to enforce strictly.  Kill nid_lock.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:50 -07:00
Benjamin Herrenschmidt 7ac674f527 vmalloc_32 should use GFP_KERNEL
I've noticed lots of failures of vmalloc_32 on machines where it
shouldn't have failed unless it was doing an atomic operation.

Looking closely, I noticed that:

#if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
#define GFP_VMALLOC32 GFP_DMA32
#elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
#define GFP_VMALLOC32 GFP_DMA
#else
#define GFP_VMALLOC32 GFP_KERNEL
#endif

Which seems to be incorrect, it should always -or- in the DMA flags
on top of GFP_KERNEL, thus this patch.

This fixes frequent errors launchin X with the nouveau DRM for example.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Dave Airlie <airlied@linux.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:50 -07:00
David Howells ea02e3dde3 FRV: work around a possible compiler bug
Work around a possible bug in the FRV compiler.

What appears to be happening is that gcc resolves the
__builtin_constant_p() in kmalloc() to true, but then fails to reduce the
therefore constant conditions in the if-statements it guards to constant
results.

When compiling with -O2 or -Os, one single spurious error crops up in
cpuup_callback() in mm/slab.c.  This can be avoided by making the memsize
variable const.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:50 -07:00
Andrew Morton 3abf7afd40 dequeue_huge_page() warning fix
mm/hugetlb.c: In function `dequeue_huge_page':
mm/hugetlb.c:72: warning: 'nid' might be used uninitialized in this function

Cc: Christoph Lameter <clameter@sgi.com>
Cc: Adam Litke <agl@us.ibm.com>
Cc: David Gibson <hermes@gibson.dropbear.id.au>
Cc: William Lee Irwin III <wli@holomorphy.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:50 -07:00
Ollie Wild b6a2fea393 mm: variable length argument support
Remove the arg+env limit of MAX_ARG_PAGES by copying the strings directly from
the old mm into the new mm.

We create the new mm before the binfmt code runs, and place the new stack at
the very top of the address space.  Once the binfmt code runs and figures out
where the stack should be, we move it downwards.

It is a bit peculiar in that we have one task with two mm's, one of which is
inactive.

[a.p.zijlstra@chello.nl: limit stack size]
Signed-off-by: Ollie Wild <aaw@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <linux-arch@vger.kernel.org>
Cc: Hugh Dickins <hugh@veritas.com>
[bunk@stusta.de: unexport bprm_mm_init]
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:45 -07:00
Fengguang Wu f9acc8c7b3 readahead: sanify file_ra_state names
Rename some file_ra_state variables and remove some accessors.

It results in much simpler code.
Kudos to Rusty!

Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:44 -07:00
Rusty Russell cf914a7d65 readahead: split ondemand readahead interface into two functions
Split ondemand readahead interface into two functions.  I think this makes it
a little clearer for non-readahead experts (like Rusty).

Internally they both call ondemand_readahead(), but the page argument is
changed to an obvious boolean flag.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:44 -07:00
Fengguang Wu fe3cba17c4 mm: share PG_readahead and PG_reclaim
Share the same page flag bit for PG_readahead and PG_reclaim.

One is used only on file reads, another is only for emergency writes.  One
is used mostly for fresh/young pages, another is for old pages.

Combinations of possible interactions are:

a) clear PG_reclaim => implicit clear of PG_readahead
	it will delay an asynchronous readahead into a synchronous one
	it actually does _good_ for readahead:
		the pages will be reclaimed soon, it's readahead thrashing!
		in this case, synchronous readahead makes more sense.

b) clear PG_readahead => implicit clear of PG_reclaim
	one(and only one) page will not be reclaimed in time
	it can be avoided by checking PageWriteback(page) in readahead first

c) set PG_reclaim => implicit set of PG_readahead
	will confuse readahead and make it restart the size rampup process
	it's a trivial problem, and can mostly be avoided by checking
	PageWriteback(page) first in readahead

d) set PG_readahead => implicit set of PG_reclaim
	PG_readahead will never be set on already cached pages.
	PG_reclaim will always be cleared on dirtying a page.
	so not a problem.

In summary,
	a)   we get better behavior
	b,d) possible interactions can be avoided
	c)   racy condition exists that might affect readahead, but the chance
	     is _really_ low, and the hurt on readahead is trivial.

Compound pages also use PG_reclaim, but for now they do not interact with
reclaim/readahead code.

Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:44 -07:00
Fengguang Wu c743d96b6d readahead: remove the old algorithm
Remove the old readahead algorithm.

Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Cc: Steven Pratt <slpratt@austin.ibm.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:44 -07:00
Fengguang Wu 3ea89ee86a readahead: convert filemap invocations
Convert filemap reads to use on-demand readahead.

The new call scheme is to
- call readahead on non-cached page
- call readahead on look-ahead page
- update prev_index when finished with the read request

Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Cc: Steven Pratt <slpratt@austin.ibm.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:44 -07:00
Fengguang Wu 122a21d11c readahead: on-demand readahead logic
This is a minimal readahead algorithm that aims to replace the current one.
It is more flexible and reliable, while maintaining almost the same behavior
and performance.  Also it is full integrated with adaptive readahead.

It is designed to be called on demand:
	- on a missing page, to do synchronous readahead
	- on a lookahead page, to do asynchronous readahead

In this way it eliminated the awkward workarounds for cache hit/miss,
readahead thrashing, retried read, and unaligned read.  It also adopts the
data structure introduced by adaptive readahead, parameterizes readahead
pipelining with `lookahead_index', and reduces the current/ahead windows to
one single window.

HEURISTICS

The logic deals with four cases:

	- sequential-next
		found a consistent readahead window, so push it forward

	- random
		standalone small read, so read as is

	- sequential-first
		create a new readahead window for a sequential/oversize request

	- lookahead-clueless
		hit a lookahead page not associated with the readahead window,
		so create a new readahead window and ramp it up

In each case, three parameters are determined:

	- readahead index: where the next readahead begins
	- readahead size:  how much to readahead
	- lookahead size:  when to do the next readahead (for pipelining)

BEHAVIORS

The old behaviors are maximally preserved for trivial sequential/random reads.
Notable changes are:

	- It no longer imposes strict sequential checks.
	  It might help some interleaved cases, and clustered random reads.
	  It does introduce risks of a random lookahead hit triggering an
	  unexpected readahead. But in general it is more likely to do good
	  than to do evil.

	- Interleaved reads are supported in a minimal way.
	  Their chances of being detected and proper handled are still low.

	- Readahead thrashings are better handled.
	  The current readahead leads to tiny average I/O sizes, because it
	  never turn back for the thrashed pages.  They have to be fault in
	  by do_generic_mapping_read() one by one.  Whereas the on-demand
	  readahead will redo readahead for them.

OVERHEADS

The new code reduced the overheads of

	- excessively calling the readahead routine on small sized reads
	  (the current readahead code insists on seeing all requests)

	- doing a lot of pointless page-cache lookups for small cached files
	  (the current readahead only turns itself off after 256 cache hits,
	  unfortunately most files are < 1MB, so never see that chance)

That accounts for speedup of
	- 0.3% on 1-page sequential reads on sparse file
	- 1.2% on 1-page cache hot sequential reads
	- 3.2% on 256-page cache hot sequential reads
	- 1.3% on cache hot `tar /lib`

However, it does introduce one extra page-cache lookup per cache miss, which
impacts random reads slightly. That's 1% overheads for 1-page random reads on
sparse file.

PERFORMANCE

The basic benchmark setup is
	- 2.6.20 kernel with on-demand readahead
	- 1MB max readahead size
	- 2.9GHz Intel Core 2 CPU
	- 2GB memory
	- 160G/8M Hitachi SATA II 7200 RPM disk

The benchmarks show that
	- it maintains the same performance for trivial sequential/random reads
	- sysbench/OLTP performance on MySQL gains up to 8%
	- performance on readahead thrashing gains up to 3 times

iozone throughput (KB/s): roughly the same
==========================================
iozone -c -t1 -s 4096m -r 64k

			       2.6.20          on-demand      gain
first run
	  "  Initial write "   61437.27        64521.53      +5.0%
	  "        Rewrite "   47893.02        48335.20      +0.9%
	  "           Read "   62111.84        62141.49      +0.0%
	  "        Re-read "   62242.66        62193.17      -0.1%
	  "   Reverse Read "   50031.46        49989.79      -0.1%
	  "    Stride read "    8657.61         8652.81      -0.1%
	  "    Random read "   13914.28        13898.23      -0.1%
	  " Mixed workload "   19069.27        19033.32      -0.2%
	  "   Random write "   14849.80        14104.38      -5.0%
	  "         Pwrite "   62955.30        65701.57      +4.4%
	  "          Pread "   62209.99        62256.26      +0.1%

second run
	  "  Initial write "   60810.31        66258.69      +9.0%
	  "        Rewrite "   49373.89        57833.66     +17.1%
	  "           Read "   62059.39        62251.28      +0.3%
	  "        Re-read "   62264.32        62256.82      -0.0%
	  "   Reverse Read "   49970.96        50565.72      +1.2%
	  "    Stride read "    8654.81         8638.45      -0.2%
	  "    Random read "   13901.44        13949.91      +0.3%
	  " Mixed workload "   19041.32        19092.04      +0.3%
	  "   Random write "   14019.99        14161.72      +1.0%
	  "         Pwrite "   64121.67        68224.17      +6.4%
	  "          Pread "   62225.08        62274.28      +0.1%

In summary, writes are unstable, reads are pretty close on average:

			  access pattern  2.6.20  on-demand   gain
				   Read  62085.61  62196.38  +0.2%
				Re-read  62253.49  62224.99  -0.0%
			   Reverse Read  50001.21  50277.75  +0.6%
			    Stride read   8656.21   8645.63  -0.1%
			    Random read  13907.86  13924.07  +0.1%
	 		 Mixed workload  19055.29  19062.68  +0.0%
				  Pread  62217.53  62265.27  +0.1%

aio-stress: roughly the same
============================
aio-stress -l -s4096 -r128 -t1 -o1 knoppix511-dvd-cn.iso
aio-stress -l -s4096 -r128 -t1 -o3 knoppix511-dvd-cn.iso

					2.6.20      on-demand  delta
			sequential	 92.57s      92.54s    -0.0%
			random		311.87s     312.15s    +0.1%

sysbench fileio: roughly the same
=================================
sysbench --test=fileio --file-io-mode=async --file-test-mode=rndrw \
	 --file-total-size=4G --file-block-size=64K \
	 --num-threads=001 --max-requests=10000 --max-time=900 run

				threads    2.6.20   on-demand    delta
		first run
				      1   59.1974s    59.2262s  +0.0%
				      2   58.0575s    58.2269s  +0.3%
				      4   48.0545s    47.1164s  -2.0%
				      8   41.0684s    41.2229s  +0.4%
				     16   35.8817s    36.4448s  +1.6%
				     32   32.6614s    32.8240s  +0.5%
				     64   23.7601s    24.1481s  +1.6%
				    128   24.3719s    23.8225s  -2.3%
				    256   23.2366s    22.0488s  -5.1%

		second run
				      1   59.6720s    59.5671s  -0.2%
				      8   41.5158s    41.9541s  +1.1%
				     64   25.0200s    23.9634s  -4.2%
				    256   22.5491s    20.9486s  -7.1%

Note that the numbers are not very stable because of the writes.
The overall performance is close when we sum all seconds up:

                sum all up               495.046s    491.514s   -0.7%

sysbench oltp (trans/sec): up to 8% gain
========================================
sysbench --test=oltp --oltp-table-size=10000000 --oltp-read-only \
	 --mysql-socket=/var/run/mysqld/mysqld.sock \
	 --mysql-user=root --mysql-password=readahead \
	 --num-threads=064 --max-requests=10000 --max-time=900 run

	10000-transactions run
				threads    2.6.20   on-demand    gain
				      1     62.81       64.56   +2.8%
				      2     67.97       70.93   +4.4%
				      4     81.81       85.87   +5.0%
				      8     94.60       97.89   +3.5%
				     16     99.07      104.68   +5.7%
				     32     95.93      104.28   +8.7%
				     64     96.48      103.68   +7.5%
	5000-transactions run
				      1     48.21       48.65   +0.9%
				      8     68.60       70.19   +2.3%
				     64     70.57       74.72   +5.9%
	2000-transactions run
				      1     37.57       38.04   +1.3%
				      2     38.43       38.99   +1.5%
				      4     45.39       46.45   +2.3%
				      8     51.64       52.36   +1.4%
				     16     54.39       55.18   +1.5%
				     32     52.13       54.49   +4.5%
				     64     54.13       54.61   +0.9%

That's interesting results. Some investigations show that
	- MySQL is accessing the db file non-uniformly: some parts are
	  more hot than others
	- It is mostly doing 4-page random reads, and sometimes doing two
	  reads in a row, the latter one triggers a 16-page readahead.
	- The on-demand readahead leaves many lookahead pages (flagged
	  PG_readahead) there. Many of them will be hit, and trigger
	  more readahead pages. Which might save more seeks.
	- Naturally, the readahead windows tend to lie in hot areas,
	  and the lookahead pages in hot areas is more likely to be hit.
	- The more overall read density, the more possible gain.

That also explains the adaptive readahead tricks for clustered random reads.

readahead thrashing: 3 times better
===================================
We boot kernel with "mem=128m single", and start a 100KB/s stream on every
second, until reaching 200 streams.

			      max throughput     min avg I/O size
		2.6.20:            5MB/s               16KB
		on-demand:        15MB/s              140KB

Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Cc: Steven Pratt <slpratt@austin.ibm.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:44 -07:00
Fengguang Wu 5ce1110b92 readahead: data structure and routines
Extend struct file_ra_state to support the on-demand readahead logic.  Also
define some helpers for it.

Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Cc: Steven Pratt <slpratt@austin.ibm.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:44 -07:00
Fengguang Wu f615bfca46 readahead: MIN_RA_PAGES/MAX_RA_PAGES macros
Define two convenient macros for read-ahead:
	- MAX_RA_PAGES: rounded down counterpart of VM_MAX_READAHEAD
	- MIN_RA_PAGES: rounded _up_ counterpart of VM_MIN_READAHEAD

Note that the rounded up MIN_RA_PAGES will work flawlessly with _large_
page sizes like 64k.

Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Cc: Steven Pratt <slpratt@austin.ibm.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:43 -07:00
Fengguang Wu 46fc3e7b4e readahead: add look-ahead support to __do_page_cache_readahead()
Add look-ahead support to __do_page_cache_readahead().

It works by
	- mark the Nth backwards page with PG_readahead,
	(which instructs the page's first reader to invoke readahead)
	- and only do the marking for newly allocated pages.
	(to prevent blindly doing readahead on already cached pages)

Look-ahead is a technique to achieve I/O pipelining:

While the application is working through a chunk of cached pages, the kernel
reads-ahead the next chunk of pages _before_ time of need.  It effectively
hides low level I/O latencies to high level applications.

Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Cc: Steven Pratt <slpratt@austin.ibm.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:43 -07:00
Fengguang Wu d77c2d7cc5 readahead: introduce PG_readahead
Introduce a new page flag: PG_readahead.

It acts as a look-ahead mark, which tells the page reader: Hey, it's time to
invoke the read-ahead logic.  For the sake of I/O pipelining, don't wait until
it runs out of cached pages!

Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Cc: Steven Pratt <slpratt@austin.ibm.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:43 -07:00
Miklos Szeredi 3ee6dafc67 only allow nonlinear vmas for ram backed filesystems
page_mkclean() doesn't re-protect ptes for non-linear mappings, so a later
re-dirty through such a mapping will not generate a fault, PG_dirty will
not reflect the dirty state and the dirty count will be skewed.  This
implies that msync() is also currently broken for nonlinear mappings.

The easiest solution is to emulate remap_file_pages on non-linear mappings
with simple mmap() for non ram-backed filesystems.  Applications continue
to work (albeit slower), as long as the number of remappings remain below
the maximum vma count.

However all currently known real uses of non-linear mappings are for ram
backed filesystems, which this patch doesn't affect.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:41 -07:00
Nick Piggin 79352894b2 mm: fix clear_page_dirty_for_io vs fault race
Fix msync data loss and (less importantly) dirty page accounting
inaccuracies due to the race remaining in clear_page_dirty_for_io().

The deleted comment explains what the race was, and the added comments
explain how it is fixed.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:41 -07:00
Nick Piggin 83c54070ee mm: fault feedback #2
This patch completes Linus's wish that the fault return codes be made into
bit flags, which I agree makes everything nicer.  This requires requires
all handle_mm_fault callers to be modified (possibly the modifications
should go further and do things like fault accounting in handle_mm_fault --
however that would be for another patch).

[akpm@linux-foundation.org: fix alpha build]
[akpm@linux-foundation.org: fix s390 build]
[akpm@linux-foundation.org: fix sparc build]
[akpm@linux-foundation.org: fix sparc64 build]
[akpm@linux-foundation.org: fix ia64 build]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ian Molton <spyro@f2s.com>
Cc: Bryan Wu <bryan.wu@analog.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Greg Ungerer <gerg@uclinux.org>
Cc: Matthew Wilcox <willy@debian.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
Cc: Richard Curnow <rc@rc0.org.uk>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp>
Cc: Chris Zankel <chris@zankel.net>
Acked-by: Kyle McMartin <kyle@mcmartin.ca>
Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Still apparently needs some ARM and PPC loving - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:41 -07:00
Nick Piggin d0217ac04c mm: fault feedback #1
Change ->fault prototype.  We now return an int, which contains
VM_FAULT_xxx code in the low byte, and FAULT_RET_xxx code in the next byte.
 FAULT_RET_ code tells the VM whether a page was found, whether it has been
locked, and potentially other things.  This is not quite the way he wanted
it yet, but that's changed in the next patch (which requires changes to
arch code).

This means we no longer set VM_CAN_INVALIDATE in the vma in order to say
that a page is locked which requires filemap_nopage to go away (because we
can no longer remain backward compatible without that flag), but we were
going to do that anyway.

struct fault_data is renamed to struct vm_fault as Linus asked. address
is now a void __user * that we should firmly encourage drivers not to use
without really good reason.

The page is now returned via a page pointer in the vm_fault struct.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:41 -07:00
Mark Fasheh 6967614761 ocfs2: release page lock before calling ->page_mkwrite
__do_fault() was calling ->page_mkwrite() with the page lock held, which
violates the locking rules for that callback.  Release and retake the page
lock around the callback to avoid deadlocking file systems which manually
take it.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:41 -07:00
Nick Piggin 54cb8821de mm: merge populate and nopage into fault (fixes nonlinear)
Nonlinear mappings are (AFAIKS) simply a virtual memory concept that encodes
the virtual address -> file offset differently from linear mappings.

->populate is a layering violation because the filesystem/pagecache code
should need to know anything about the virtual memory mapping.  The hitch here
is that the ->nopage handler didn't pass down enough information (ie.  pgoff).
 But it is more logical to pass pgoff rather than have the ->nopage function
calculate it itself anyway (because that's a similar layering violation).

Having the populate handler install the pte itself is likewise a nasty thing
to be doing.

This patch introduces a new fault handler that replaces ->nopage and
->populate and (later) ->nopfn.  Most of the old mechanism is still in place
so there is a lot of duplication and nice cleanups that can be removed if
everyone switches over.

The rationale for doing this in the first place is that nonlinear mappings are
subject to the pagefault vs invalidate/truncate race too, and it seemed stupid
to duplicate the synchronisation logic rather than just consolidate the two.

After this patch, MAP_NONBLOCK no longer sets up ptes for pages present in
pagecache.  Seems like a fringe functionality anyway.

NOPAGE_REFAULT is removed.  This should be implemented with ->fault, and no
users have hit mainline yet.

[akpm@linux-foundation.org: cleanup]
[randy.dunlap@oracle.com: doc. fixes for readahead]
[akpm@linux-foundation.org: build fix]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:41 -07:00
Nick Piggin d00806b183 mm: fix fault vs invalidate race for linear mappings
Fix the race between invalidate_inode_pages and do_no_page.

Andrea Arcangeli identified a subtle race between invalidation of pages from
pagecache with userspace mappings, and do_no_page.

The issue is that invalidation has to shoot down all mappings to the page,
before it can be discarded from the pagecache.  Between shooting down ptes to
a particular page, and actually dropping the struct page from the pagecache,
do_no_page from any process might fault on that page and establish a new
mapping to the page just before it gets discarded from the pagecache.

The most common case where such invalidation is used is in file truncation.
This case was catered for by doing a sort of open-coded seqlock between the
file's i_size, and its truncate_count.

Truncation will decrease i_size, then increment truncate_count before
unmapping userspace pages; do_no_page will read truncate_count, then find the
page if it is within i_size, and then check truncate_count under the page
table lock and back out and retry if it had subsequently been changed (ptl
will serialise against unmapping, and ensure a potentially updated
truncate_count is actually visible).

Complexity and documentation issues aside, the locking protocol fails in the
case where we would like to invalidate pagecache inside i_size.  do_no_page
can come in anytime and filemap_nopage is not aware of the invalidation in
progress (as it is when it is outside i_size).  The end result is that
dangling (->mapping == NULL) pages that appear to be from a particular file
may be mapped into userspace with nonsense data.  Valid mappings to the same
place will see a different page.

Andrea implemented two working fixes, one using a real seqlock, another using
a page->flags bit.  He also proposed using the page lock in do_no_page, but
that was initially considered too heavyweight.  However, it is not a global or
per-file lock, and the page cacheline is modified in do_no_page to increment
_count and _mapcount anyway, so a further modification should not be a large
performance hit.  Scalability is not an issue.

This patch implements this latter approach.  ->nopage implementations return
with the page locked if it is possible for their underlying file to be
invalidated (in that case, they must set a special vm_flags bit to indicate
so).  do_no_page only unlocks the page after setting up the mapping
completely.  invalidation is excluded because it holds the page lock during
invalidation of each page (and ensures that the page is not mapped while
holding the lock).

This also allows significant simplifications in do_no_page, because we have
the page locked in the right place in the pagecache from the start.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:41 -07:00
Jeremy Fitzhardinge 5f4352fbff Allocate and free vmalloc areas
Allocate/release a chunk of vmalloc address space:
 alloc_vm_area reserves a chunk of address space, and makes sure all
 the pagetables are constructed for that address range - but no pages.

 free_vm_area releases the address space range.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Ian Pratt <ian.pratt@xensource.com>
Signed-off-by: Christian Limpach <Christian.Limpach@cl.cam.ac.uk>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: "Jan Beulich" <JBeulich@novell.com>
Cc: "Andi Kleen" <ak@muc.de>
2007-07-18 08:47:41 -07:00
Jeremy Fitzhardinge 1e66df3ee3 add kstrndup
Add a kstrndup function, modelled on strndup.  Like strndup this
returns a string copied into its own allocated memory, but it copies
no more than the specified number of bytes from the source.

Remove private strndup() from irda code.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@mandriva.com>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Panagiotis Issaris <takis@issaris.org>
Cc: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
2007-07-18 08:47:39 -07:00
Meelap Shah c2f1a551de knfsd: nfsd4: vary maximum delegation limit based on RAM size
Our original NFSv4 delegation policy was to give out a read delegation on any
open when it was possible to.

Since the lifetime of a delegation isn't limited to that of an open, a client
may quite reasonably hang on to a delegation as long as it has the inode
cached.  This becomes an obvious problem the first time a client's inode cache
approaches the size of the server's total memory.

Our first quick solution was to add a hard-coded limit.  This patch makes a
mild incremental improvement by varying that limit according to the server's
total memory size, allowing at most 4 delegations per megabyte of RAM.

My quick back-of-the-envelope calculation finds that in the worst case (where
every delegation is for a different inode), a delegation could take about
1.5K, which would make the worst case usage about 6% of memory.  The new limit
works out to be about the same as the old on a 1-gig server.

[akpm@linux-foundation.org: Don't needlessly bloat vmlinux]
[akpm@linux-foundation.org: Make it right for highmem machines]
Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:07 -07:00
Christoph Hellwig a569425512 knfsd: exportfs: add exportfs.h header
currently the export_operation structure and helpers related to it are in
fs.h.  fs.h is already far too large and there are very few places needing the
export bits, so split them off into a separate header.

[akpm@linux-foundation.org: fix cifs build]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: Steven French <sfrench@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:06 -07:00
Tejun Heo 9281acea6a kallsyms: make KSYM_NAME_LEN include space for trailing '\0'
KSYM_NAME_LEN is peculiar in that it does not include the space for the
trailing '\0', forcing all users to use KSYM_NAME_LEN + 1 when allocating
buffer.  This is nonsense and error-prone.  Moreover, when the caller
forgets that it's very likely to subtly bite back by corrupting the stack
because the last position of the buffer is always cleared to zero.

This patch increments KSYM_NAME_LEN by one and updates code accordingly.

* off-by-one bug in asm-powerpc/kprobes.h::kprobe_lookup_name() macro
  is fixed.

* Where MODULE_NAME_LEN and KSYM_NAME_LEN were used together,
  MODULE_NAME_LEN was treated as if it didn't include space for the
  trailing '\0'.  Fix it.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Paulo Marques <pmarques@grupopie.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:03 -07:00
Christoph Lameter 2a7326b5bb CONFIG_BOUNCE to avoid useless inclusion of bounce buffer logic
The bounce buffer logic is included on systems that do not need it.  If a
system does not have zones like ZONE_DMA and ZONE_HIGHMEM that can lead to
the use of bounce buffers then there is no need to reserve memory pools etc
etc.  This is true f.e.  for SGI Altix.

Also nicifies the Makefile and gets rid of the tricky "and" there.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:02 -07:00
Rafael J. Wysocki 8314418629 Freezer: make kernel threads nonfreezable by default
Currently, the freezer treats all tasks as freezable, except for the kernel
threads that explicitly set the PF_NOFREEZE flag for themselves.  This
approach is problematic, since it requires every kernel thread to either
set PF_NOFREEZE explicitly, or call try_to_freeze(), even if it doesn't
care for the freezing of tasks at all.

It seems better to only require the kernel threads that want to or need to
be frozen to use some freezer-related code and to remove any
freezer-related code from the other (nonfreezable) kernel threads, which is
done in this patch.

The patch causes all kernel threads to be nonfreezable by default (ie.  to
have PF_NOFREEZE set by default) and introduces the set_freezable()
function that should be called by the freezable kernel threads in order to
unset PF_NOFREEZE.  It also makes all of the currently freezable kernel
threads call set_freezable(), so it shouldn't cause any (intentional)
change of behaviour to appear.  Additionally, it updates documentation to
describe the freezing of tasks more accurately.

[akpm@linux-foundation.org: build fixes]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Nigel Cunningham <nigel@nigel.suspend2.net>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:02 -07:00
Nick Piggin 787d2214c1 fs: introduce some page/buffer invariants
It is a bug to set a page dirty if it is not uptodate unless it has
buffers.  If the page has buffers, then the page may be dirty (some buffers
dirty) but not uptodate (some buffers not uptodate).  The exception to this
rule is if the set_page_dirty caller is racing with truncate or invalidate.

A buffer can not be set dirty if it is not uptodate.

If either of these situations occurs, it indicates there could be some data
loss problem.  Some of these warnings could be a harmless one where the
page or buffer is set uptodate immediately after it is dirtied, however we
should fix those up, and enforce this ordering.

Bring the order of operations for truncate into line with those of
invalidate.  This will prevent a page from being able to go !uptodate while
we're holding the tree_lock, which is probably a good thing anyway.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:02 -07:00
Robert P. J. Day a1ed3dda0a MM: Make needlessly global hugetlb_no_page() static.
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:02 -07:00
Christoph Lameter 8ab1372fac SLUB: Fix CONFIG_SLUB_DEBUG use for CONFIG_NUMA
We currently cannot disable CONFIG_SLUB_DEBUG for CONFIG_NUMA.  Now that
embedded systems start to use NUMA we may need this.

Put an #ifdef around places where NUMA only code uses fields only valid
for CONFIG_SLUB_DEBUG.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:02 -07:00
Christoph Lameter a0e1d1be20 SLUB: Move sysfs operations outside of slub_lock
Sysfs can do a gazillion things when called.  Make sure that we do not call
any sysfs functions while holding the slub_lock.

Just protect the essentials:

1. The list of all slab caches
2. The kmalloc_dma array
3. The ref counters of the slabs.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:02 -07:00
Christoph Lameter 434e245ddd SLUB: Do not allocate object bit array on stack
The objects per slab increase with the current patches in mm since we allow up
to order 3 allocs by default.  More patches in mm actually allow to use 2M or
higher sized slabs.  For slab validation we need per object bitmaps in order
to check a slab.  We end up with up to 64k objects per slab resulting in a
potential requirement of 8K stack space.  That does not look good.

Allocate the bit arrays via kmalloc.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:02 -07:00
Christoph Lameter 94f6030ca7 Slab allocators: Replace explicit zeroing with __GFP_ZERO
kmalloc_node() and kmem_cache_alloc_node() were not available in a zeroing
variant in the past.  But with __GFP_ZERO it is possible now to do zeroing
while allocating.

Use __GFP_ZERO to remove the explicit clearing of memory via memset whereever
we can.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:02 -07:00
Christoph Lameter 81cda66261 Slab allocators: Cleanup zeroing allocations
It becomes now easy to support the zeroing allocs with generic inline
functions in slab.h.  Provide inline definitions to allow the continued use of
kzalloc, kmem_cache_zalloc etc but remove other definitions of zeroing
functions from the slab allocators and util.c.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:01 -07:00
Christoph Lameter ce15fea827 SLUB: Do not use length parameter in slab_alloc()
We can get to the length of the object through the kmem_cache_structure.  The
additional parameter does no good and causes the compiler to generate bad
code.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:01 -07:00
Christoph Lameter 12ad6843dd SLUB: Style fix up the loop to disable small slabs
Do proper spacing and we only need to do this in steps of 8.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:01 -07:00
Adrian Bunk 5af328a510 mm/slub.c: make code static
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:01 -07:00
Christoph Lameter 7b55f620e6 SLUB: Simplify dma index -> size calculation
There is no need to caculate the dma slab size ourselves. We can simply
lookup the size of the corresponding non dma slab.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:01 -07:00
Christoph Lameter f1b2633936 SLUB: faster more efficient slab determination for __kmalloc
kmalloc_index is a long series of comparisons.  The attempt to replace
kmalloc_index with something more efficient like ilog2 failed due to compiler
issues with constant folding on gcc 3.3 / powerpc.

kmalloc_index()'es long list of comparisons works fine for constant folding
since all the comparisons are optimized away.  However, SLUB also uses
kmalloc_index to determine the slab to use for the __kmalloc_xxx functions.
This leads to a large set of comparisons in get_slab().

The patch here allows to get rid of that list of comparisons in get_slab():

1. If the requested size is larger than 192 then we can simply use
   fls to determine the slab index since all larger slabs are
   of the power of two type.

2. If the requested size is smaller then we cannot use fls since there
   are non power of two caches to be considered. However, the sizes are
   in a managable range. So we divide the size by 8. Then we have only
   24 possibilities left and then we simply look up the kmalloc index
   in a table.

Code size of slub.o decreases by more than 200 bytes through this patch.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:01 -07:00
Christoph Lameter dfce8648d6 SLUB: do proper locking during dma slab creation
We modify the kmalloc_cache_dma[] array without proper locking.  Do the proper
locking and undo the dma cache creation if another processor has already
created it.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:01 -07:00
Christoph Lameter 2e443fd003 SLUB: extract dma_kmalloc_cache from get_cache.
The rarely used dma functionality in get_slab() makes the function too
complex.  The compiler begins to spill variables from the working set onto the
stack.  The created function is only used in extremely rare cases so make sure
that the compiler does not decide on its own to merge it back into get_slab().

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:01 -07:00
Christoph Lameter 0c71001320 SLUB: add some more inlines and #ifdef CONFIG_SLUB_DEBUG
Add #ifdefs around data structures only needed if debugging is compiled into
SLUB.

Add inlines to small functions to reduce code size.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:01 -07:00
Christoph Lameter d07dbea464 Slab allocators: support __GFP_ZERO in all allocators
A kernel convention for many allocators is that if __GFP_ZERO is passed to an
allocator then the allocated memory should be zeroed.

This is currently not supported by the slab allocators.  The inconsistency
makes it difficult to implement in derived allocators such as in the uncached
allocator and the pool allocators.

In addition the support zeroed allocations in the slab allocators does not
have a consistent API.  There are no zeroing allocator functions for NUMA node
placement (kmalloc_node, kmem_cache_alloc_node).  The zeroing allocations are
only provided for default allocs (kzalloc, kmem_cache_zalloc_node).
__GFP_ZERO will make zeroing universally available and does not require any
addititional functions.

So add the necessary logic to all slab allocators to support __GFP_ZERO.

The code is added to the hot path.  The gfp flags are on the stack and so the
cacheline is readily available for checking if we want a zeroed object.

Zeroing while allocating is now a frequent operation and we seem to be
gradually approaching a 1-1 parity between zeroing and not zeroing allocs.
The current tree has 3476 uses of kmalloc vs 2731 uses of kzalloc.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:01 -07:00
Christoph Lameter 6cb8f91320 Slab allocators: consistent ZERO_SIZE_PTR support and NULL result semantics
Define ZERO_OR_NULL_PTR macro to be able to remove the checks from the
allocators.  Move ZERO_SIZE_PTR related stuff into slab.h.

Make ZERO_SIZE_PTR work for all slab allocators and get rid of the
WARN_ON_ONCE(size == 0) that is still remaining in SLAB.

Make slub return NULL like the other allocators if a too large memory segment
is requested via __kmalloc.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:01 -07:00
Christoph Lameter ef2ad80c7d Slab allocators: consolidate code for krealloc in mm/util.c
The size of a kmalloc object is readily available via ksize().  ksize is
provided by all allocators and thus we can implement krealloc in a generic
way.

Implement krealloc in mm/util.c and drop slab specific implementations of
krealloc.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:01 -07:00
Christoph Lameter d45f39cb06 SLUB Debug: fix initial object debug state of NUMA bootstrap objects
The function we are calling to initialize object debug state during early NUMA
bootstrap sets up an inactive object giving it the wrong redzone signature.
The bootstrap nodes are active objects and should have active redzone
signatures.

Currently slab validation complains and reverts the object to active state.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:01 -07:00
Christoph Lameter 6300ea7503 SLUB: ensure that the number of objects per slab stays low for high orders
Currently SLUB has no provision to deal with too high page orders that may
be specified on the kernel boot line.  If an order higher than 6 (on a 4k
platform) is generated then we will BUG() because slabs get more than 65535
objects.

Add some logic that decreases order for slabs that have too many objects.
This allow booting with slab sizes up to MAX_ORDER.

For example

	slub_min_order=10

will boot with a default slab size of 4M and reduce slab sizes for small
object sizes to lower orders if the number of objects becomes too big.
Large slab sizes like that allow a concentration of objects of the same
slab cache under as few as possible TLB entries and thus potentially
reduces TLB pressure.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:01 -07:00
Christoph Lameter 68dff6a9af SLUB slab validation: Move tracking information alloc outside of lock
We currently have to do an GFP_ATOMIC allocation because the list_lock is
already taken when we first allocate memory for tracking allocation
information.  It would be better if we could avoid atomic allocations.

Allocate a size of the tracking table that is usually sufficient (one page)
before we take the list lock.  We will then only do the atomic allocation
if we need to resize the table to become larger than a page (mostly only
needed under large NUMA because of the tracking of cpus and nodes otherwise
the table stays small).

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:01 -07:00
Christoph Lameter 5b95a4acf1 SLUB: use list_for_each_entry for loops over all slabs
Use list_for_each_entry() instead of list_for_each().

Get rid of for_all_slabs(). It had only one user. So fold it into the
callback. This also gets rid of cpu_slab_flush.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:01 -07:00
Christoph Lameter 2492268472 SLUB: change error reporting format to follow lockdep loosely
Changes the error reporting format to loosely follow lockdep.

If data corruption is detected then we generate the following lines:

============================================
BUG <slab-cache>: <problem>
--------------------------------------------

INFO: <more information> [possibly multiple times]

<object dump>

FIX <slab-cache>: <remedial action>

This also adds some more intelligence to the data corruption detection. Its
now capable of figuring out the start and end.

Add a comment on how to configure SLUB so that a production system may
continue to operate even though occasional slab corruption occur through
a misbehaving kernel component. See "Emergency operations" in
Documentation/vm/slub.txt.

[akpm@linux-foundation.org: build fix]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:01 -07:00
Rusty Russell 8e1f936b73 mm: clean up and kernelify shrinker registration
I can never remember what the function to register to receive VM pressure
is called.  I have to trace down from __alloc_pages() to find it.

It's called "set_shrinker()", and it needs Your Help.

1) Don't hide struct shrinker.  It contains no magic.
2) Don't allocate "struct shrinker".  It's not helpful.
3) Call them "register_shrinker" and "unregister_shrinker".
4) Call the function "shrink" not "shrinker".
5) Reduce the 17 lines of waffly comments to 13, but document it properly.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: David Chinner <dgc@sgi.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:00 -07:00
Andy Whitcroft 5ad333eb66 Lumpy Reclaim V4
When we are out of memory of a suitable size we enter reclaim.  The current
reclaim algorithm targets pages in LRU order, which is great for fairness at
order-0 but highly unsuitable if you desire pages at higher orders.  To get
pages of higher order we must shoot down a very high proportion of memory;
>95% in a lot of cases.

This patch set adds a lumpy reclaim algorithm to the allocator.  It targets
groups of pages at the specified order anchored at the end of the active and
inactive lists.  This encourages groups of pages at the requested orders to
move from active to inactive, and active to free lists.  This behaviour is
only triggered out of direct reclaim when higher order pages have been
requested.

This patch set is particularly effective when utilised with an
anti-fragmentation scheme which groups pages of similar reclaimability
together.

This patch set is based on Peter Zijlstra's lumpy reclaim V2 patch which forms
the foundation.  Credit to Mel Gorman for sanitity checking.

Mel said:

  The patches have an application with hugepage pool resizing.

  When lumpy-reclaim is used used with ZONE_MOVABLE, the hugepages pool can
  be resized with greater reliability.  Testing on a desktop machine with 2GB
  of RAM showed that growing the hugepage pool with ZONE_MOVABLE on it's own
  was very slow as the success rate was quite low.  Without lumpy-reclaim,
  each attempt to grow the pool by 100 pages would yield 1 or 2 hugepages.
  With lumpy-reclaim, getting 40 to 70 hugepages on each attempt was typical.

[akpm@osdl.org: ia64 pfn_to_nid fixes and loop cleanup]
[bunk@stusta.de: static declarations for internal functions]
[a.p.zijlstra@chello.nl: initial lumpy V2 implementation]
Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: Bob Picco <bob.picco@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:22:59 -07:00
Mel Gorman 7e63efef85 Add a movablecore= parameter for sizing ZONE_MOVABLE
This patch adds a new parameter for sizing ZONE_MOVABLE called
movablecore=.  While kernelcore= is used to specify the minimum amount of
memory that must be available for all allocation types, movablecore= is
used to specify the minimum amount of memory that is used for migratable
allocations.  The amount of memory used for migratable allocations
determines how large the huge page pool could be dynamically resized to at
runtime for example.

How movablecore is actually handled is that the total number of pages in
the system is calculated and a value is set for kernelcore that is

kernelcore == totalpages - movablecore

Both kernelcore= and movablecore= can be safely specified at the same time.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:22:59 -07:00
Mel Gorman ed7ed36517 handle kernelcore=: generic
This patch adds the kernelcore= parameter for x86.

Once all patches are applied, a new command-line parameter exist and a new
sysctl.  This patch adds the necessary documentation.

From: Yasunori Goto <y-goto@jp.fujitsu.com>

  When "kernelcore" boot option is specified, kernel can't boot up on ia64
  because of an infinite loop.  In addition, the parsing code can be handled
  in an architecture-independent manner.

  This patch uses common code to handle the kernelcore= parameter.  It is
  only available to architectures that support arch-independent zone-sizing
  (i.e.  define CONFIG_ARCH_POPULATES_NODE_MAP).  Other architectures will
  ignore the boot parameter.

[bunk@stusta.de: make cmdline_parse_kernelcore() static]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Acked-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:22:59 -07:00
Mel Gorman 396faf0303 Allow huge page allocations to use GFP_HIGH_MOVABLE
Huge pages are not movable so are not allocated from ZONE_MOVABLE.  However,
as ZONE_MOVABLE will always have pages that can be migrated or reclaimed, it
can be used to satisfy hugepage allocations even when the system has been
running a long time.  This allows an administrator to resize the hugepage pool
at runtime depending on the size of ZONE_MOVABLE.

This patch adds a new sysctl called hugepages_treat_as_movable.  When a
non-zero value is written to it, future allocations for the huge page pool
will use ZONE_MOVABLE.  Despite huge pages being non-movable, we do not
introduce additional external fragmentation of note as huge pages are always
the largest contiguous block we care about.

[akpm@linux-foundation.org: various fixes]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:22:59 -07:00
Mel Gorman 2a1e274acf Create the ZONE_MOVABLE zone
The following 8 patches against 2.6.20-mm2 create a zone called ZONE_MOVABLE
that is only usable by allocations that specify both __GFP_HIGHMEM and
__GFP_MOVABLE.  This has the effect of keeping all non-movable pages within a
single memory partition while allowing movable allocations to be satisfied
from either partition.  The patches may be applied with the list-based
anti-fragmentation patches that groups pages together based on mobility.

The size of the zone is determined by a kernelcore= parameter specified at
boot-time.  This specifies how much memory is usable by non-movable
allocations and the remainder is used for ZONE_MOVABLE.  Any range of pages
within ZONE_MOVABLE can be released by migrating the pages or by reclaiming.

When selecting a zone to take pages from for ZONE_MOVABLE, there are two
things to consider.  First, only memory from the highest populated zone is
used for ZONE_MOVABLE.  On the x86, this is probably going to be ZONE_HIGHMEM
but it would be ZONE_DMA on ppc64 or possibly ZONE_DMA32 on x86_64.  Second,
the amount of memory usable by the kernel will be spread evenly throughout
NUMA nodes where possible.  If the nodes are not of equal size, the amount of
memory usable by the kernel on some nodes may be greater than others.

By default, the zone is not as useful for hugetlb allocations because they are
pinned and non-migratable (currently at least).  A sysctl is provided that
allows huge pages to be allocated from that zone.  This means that the huge
page pool can be resized to the size of ZONE_MOVABLE during the lifetime of
the system assuming that pages are not mlocked.  Despite huge pages being
non-movable, we do not introduce additional external fragmentation of note as
huge pages are always the largest contiguous block we care about.

Credit goes to Andy Whitcroft for catching a large variety of problems during
review of the patches.

This patch creates an additional zone, ZONE_MOVABLE.  This zone is only usable
by allocations which specify both __GFP_HIGHMEM and __GFP_MOVABLE.  Hot-added
memory continues to be placed in their existing destination as there is no
mechanism to redirect them to a specific zone.

[y-goto@jp.fujitsu.com: Fix section mismatch of memory hotplug related code]
[akpm@linux-foundation.org: various fixes]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: William Lee Irwin III <wli@holomorphy.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:22:59 -07:00
Mel Gorman 769848c038 Add __GFP_MOVABLE for callers to flag allocations from high memory that may be migrated
It is often known at allocation time whether a page may be migrated or not.
This patch adds a flag called __GFP_MOVABLE and a new mask called
GFP_HIGH_MOVABLE.  Allocations using the __GFP_MOVABLE can be either migrated
using the page migration mechanism or reclaimed by syncing with backing
storage and discarding.

An API function very similar to alloc_zeroed_user_highpage() is added for
__GFP_MOVABLE allocations called alloc_zeroed_user_highpage_movable().  The
flags used by alloc_zeroed_user_highpage() are not changed because it would
change the semantics of an existing API.  After this patch is applied there
are no in-kernel users of alloc_zeroed_user_highpage() so it probably should
be marked deprecated if this patch is merged.

Note that this patch includes a minor cleanup to the use of __GFP_ZERO in
shmem.c to keep all flag modifications to inode->mapping in the
shmem_dir_alloc() helper function.  This clean-up suggestion is courtesy of
Hugh Dickens.

Additional credit goes to Christoph Lameter and Linus Torvalds for shaping the
concept.  Credit to Hugh Dickens for catching issues with shmem swap vector
and ramfs allocations.

[akpm@linux-foundation.org: build fix]
[hugh@veritas.com: __GFP_ZERO cleanup]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:22:59 -07:00
NeilBrown a32ea1e1f9 Fix read/truncate race
do_generic_mapping_read currently samples the i_size at the start and doesn't
do so again unless it needs to call ->readpage to load a page.  After
->readpage it has to re-sample i_size as a truncate may have caused that page
to be filled with zeros, and the read() call should not see these.

However there are other activities that might cause ->readpage to be called on
a page between the time that do_generic_mapping_read samples i_size and when
it finds that it has an uptodate page.  These include at least read-ahead and
possibly another thread performing a read.

So do_generic_mapping_read must sample i_size *after* it has an uptodate page.
 Thus the current sampling at the start and after a read can be replaced with
a sampling before the copy-out.

The same change applied to __generic_file_splice_read.

Note that this fixes any race with truncate_complete_page, but does not fix a
possible race with truncate_partial_page.  If a partial truncate happens after
do_generic_mapping_read samples i_size and before the copy_out, the nuls that
truncate_partial_page place in the page could be copied out incorrectly.

I think the best fix for that is to *not* zero out parts of the page in
truncate_partial_page, but rather to zero out the tail of a page when
increasing i_size.

Signed-off-by: Neil Brown <neilb@suse.de>
Cc: Jens Axboe <jens.axboe@oracle.com>
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:22:59 -07:00
Linus Torvalds 489de30259 Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: (209 commits)
  [POWERPC] Create add_rtc() function to enable the RTC CMOS driver
  [POWERPC] Add H_ILLAN_ATTRIBUTES hcall number
  [POWERPC] xilinxfb: Parameterize xilinxfb platform device registration
  [POWERPC] Oprofile support for Power 5++
  [POWERPC] Enable arbitary speed tty ioctls and split input/output speed
  [POWERPC] Make drivers/char/hvc_console.c:khvcd() static
  [POWERPC] Remove dead code for preventing pread() and pwrite() calls
  [POWERPC] Remove unnecessary #undef printk from prom.c
  [POWERPC] Fix typo in Ebony default DTS
  [POWERPC] Check for NULL ppc_md.init_IRQ() before calling
  [POWERPC] Remove extra return statement
  [POWERPC] pasemi: Don't auto-select CONFIG_EMBEDDED
  [POWERPC] pasemi: Rename platform
  [POWERPC] arch/powerpc/kernel/sysfs.c: Move NUMA exports
  [POWERPC] Add __read_mostly support for powerpc
  [POWERPC] Modify sched_clock() to make CONFIG_PRINTK_TIME more sane
  [POWERPC] Create a dummy zImage if no valid platform has been selected
  [POWERPC] PS3: Bootwrapper support.
  [POWERPC] powermac i2c: Use mutex
  [POWERPC] Schedule removal of arch/ppc
  ...

Fixed up conflicts manually in:

	Documentation/feature-removal-schedule.txt
	arch/powerpc/kernel/pci_32.c
	arch/powerpc/kernel/pci_64.c
	include/asm-powerpc/pci.h

and asked the powerpc people to double-check the result..
2007-07-16 17:58:08 -07:00
Linus Torvalds b91cba52e9 Merge master.kernel.org:/pub/scm/linux/kernel/git/lethal/sh-2.6
* master.kernel.org:/pub/scm/linux/kernel/git/lethal/sh-2.6: (68 commits)
  sh: sh-rtc support for SH7709.
  sh: Revert __xdiv64_32 size change.
  sh: Update r7785rp defconfig.
  sh: Export div symbols for GCC 4.2 and ST GCC.
  sh: fix race in parallel out-of-tree build
  sh: Kill off dead mach.c for hp6xx.
  sh: hd64461.h cleanup and added comments.
  sh: Update the alignment when 4K stacks are used.
  sh: Add a .bss.page_aligned section for 4K stacks.
  sh: Don't let SH-4A clobber SH-4 CFLAGS.
  sh: Add parport stub for SuperIO ports.
  sh: Drop -Wa,-dsp for DSP tuning.
  sh: Update dreamcast defconfig.
  fb: pvr2fb: A few more __devinit annotations for PCI.
  fb: pvr2fb: Fix up section mismatch warnings.
  sh: Select IPR-IRQ for SH7091.
  sh: Correct __xdiv64_32/div64_32 return value size.
  sh: Fix timer-tmu build for SH-3.
  sh: Add cpu and mach links to CLEAN_FILES.
  sh: Preliminary support for the SH-X3 CPU.
  ...
2007-07-16 10:32:02 -07:00
Rusty Russell c80e7a826c permit mempool_free(NULL)
Christian Borntraeger points out that mempool_free() doesn't noop when
handed NULL.  This is inconsistent with the other free-like functions
in the kernel.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:52 -07:00
Adrian Bunk 8f8a68ee48 remove mm/backing-dev.c:congestion_wait_interruptible()
congestion_wait_interruptible() is no longer used.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:52 -07:00
Andrew Morton 3e733f071e dirty_writeback_centisecs_handler() cleanup
Repair indenting bustage.

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:47 -07:00
Akinobu Mita 54114994f4 fault-injection: add min-order parameter to fail_page_alloc
Limiting smaller allocation failures by fault injection helps to find real
possible bugs.  Because higher order allocations are likely to fail and
zero-order allocations are not likely to fail.

This patch adds min-order parameter to fail_page_alloc.  It specifies the
minimum page allocation order to be injected failures.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:45 -07:00
Micah Cowan 17973f5af7 Only send SIGXFSZ when exceeding rlimits.
Some users have been having problems with utilities like cp or dd dumping
core when they try to copy a file that's too large for the destination
filesystem (typically, > 4gb).  Apparently, some defunct standards required
SIGXFSZ to be sent in such circumstances, but SUS only requires/allows it
for when a written file exceeds the process's resource limits.  I'd like to
limit SIGXFSZs to the bare minimum required by SUS.

Patch sent per http://lkml.org/lkml/2007/4/10/302

Signed-off-by: Micah Cowan <micahcowan@ubuntu.com>
Acked-by: Alan Cox <alan@redhat.com>
Cc: <reiserfs-dev@namesys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:43 -07:00
Stephen Rothwell f057eac0d7 Introduce CONFIG_VIRT_TO_BUS
Make some offending drivers depend on it and set CONFIG_ARCH_NO_VIRT_TO_BUS
for ppc64 so that we don't build those drivers.

This gets PowerPC allmodconfig and allyesconfig much closer to building.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Al Viro <viro@ftp.linux.org.uk>
Acked-by: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:42 -07:00
Greg Ungerer 57c8f63e8e nommu: stub expand_stack() for nommu case
Be consistent with VM mmap, implement expand_stack().  We can't actually do
anything other than return an error in the no MMU case though.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:37 -07:00
Miklos Szeredi 0165ab4435 split mmap
This is a straightforward split of do_mmap_pgoff() into two functions:

 - do_mmap_pgoff() checks the parameters, and calculates the vma
   flags.  Then it calls

 - mmap_region(), which does the actual mapping

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:37 -07:00
akpm@linux-foundation.org c44939ecb6 NeilBrown <neilb@suse.de>
The do_loop_readv_writev implementation of readv breaks out of the loop as
soon as a single read request didn't fill it's buffer:

		if (nr != len)
			break;

The generic_file_aio_read version doesn't.  So if it hits EOF before the end
of the list of buffers, it will try again on the next buffer.  If the file was
extended in the mean time, this will produce a bad result.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:37 -07:00
Herbert van den Bergh 5ed44a401d do not limit locked memory when RLIMIT_MEMLOCK is RLIM_INFINITY
Fix a bug in mm/mlock.c on 32-bit architectures that prevents a user from
locking more than 4GB of shared memory, or allocating more than 4GB of
shared memory in hugepages, when rlim[RLIMIT_MEMLOCK] is set to
RLIM_INFINITY.

Signed-off-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com>
Acked-by: Chris Mason <chris.mason@oracle.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:37 -07:00
Paul Mundt 84a01c2f8e slob: sparsemem support
Currently slob is disabled if we're using sparsemem, due to an earlier
patch from Goto-san.  Slob and static sparsemem work without any trouble as
it is, and the only hiccup is a missing slab_is_available() in the case of
sparsemem extreme.  With this, we're rid of the last set of restrictions
for slob usage.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Matt Mackall <mpm@selenic.com>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:36 -07:00
Dan Aloni b49ad484c5 mm/page_alloc.c: lower printk severity
Signed-off-by: Dan Aloni <da-x@monatomic.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:36 -07:00
Paul Mundt 6193a2ff18 slob: initial NUMA support
This adds preliminary NUMA support to SLOB, primarily aimed at systems with
small nodes (tested all the way down to a 128kB SRAM block), whether
asymmetric or otherwise.

We follow the same conventions as SLAB/SLUB, preferring current node
placement for new pages, or with explicit placement, if a node has been
specified.  Presently on UP NUMA this has the side-effect of preferring
node#0 allocations (since numa_node_id() == 0, though this could be
reworked if we could hand off a pfn to determine node placement), so
single-CPU NUMA systems will want to place smaller nodes further out in
terms of node id.  Once a page has been bound to a node (via explicit node
id typing), we only do block allocations from partial free pages that have
a matching node id in the page flags.

The current implementation does have some scalability problems, in that all
partial free pages are tracked in the global freelist (with contention due
to the single spinlock).  However, these are things that are being reworked
for SMP scalability first, while things like per-node freelists can easily
be built on top of this sort of functionality once it's been added.

More background can be found in:

	http://marc.info/?l=linux-mm&m=118117916022379&w=2
	http://marc.info/?l=linux-mm&m=118170446306199&w=2
	http://marc.info/?l=linux-mm&m=118187859420048&w=2

and subsequent threads.

Acked-by: Christoph Lameter <clameter@sgi.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:36 -07:00
Jason Baron f797779324 speed up madvise_need_mmap_write() usage
In the new madvise_need_mmap_write() call we can avoid an extra case
statement and function call as follows.

Signed-off-by: Jason Baron <jbaron@redhat.com>
Cc: Nishanth Aravamudan <nacc@us.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:36 -07:00
Adrian Bunk 897e679b17 mm/slab.c: start_cpu_timer() should be __cpuinit
start_cpu_timer() should be __cpuinit (which also matches what it's
callers are).

__devinit didn't cause problems, it simply wasted a few bytes of memory
for the common CONFIG_HOTPLUG_CPU=n case.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:36 -07:00
Paul Mundt 6ea6e6887d mm: more __meminit annotations
Currently zone_spanned_pages_in_node() and zone_absent_pages_in_node() are
non-static for ARCH_POPULATES_NODE_MAP and static otherwise.  However, only
the non-static versions are __meminit annotated, despite only being called
from __meminit functions in either case.

zone_init_free_lists() is currently non-static and not __meminit annotated
either, despite only being called once in the entire tree by
init_currently_empty_zone(), which too is __meminit.  So make it static and
properly annotated.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:36 -07:00
Jan Beulich 8f0accc862 kill vmalloc_earlyreserve
This symbol got orphaned quite a while ago.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:36 -07:00
Jan Beulich 98011f569e mm: fix improper .init-type section references
.. which modpost started warning about.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:36 -07:00
Paul Mundt 140d5a4904 numa: mempolicy: trivial debug fixes.
Enabling debugging fails to build due to the nodemask variable in
do_mbind() having changed names, and then oopses on boot due to the
assumption that the nodemask can be dereferenced -- which doesn't work out
so well when the policy is changed to MPOL_DEFAULT with a NULL nodemask by
numa_default_policy().

This fixes it up, and switches from PDprintk() to pr_debug() while
we're at it.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:36 -07:00
Ethan Solomita 462e00cc71 oom: stop allocating user memory if TIF_MEMDIE is set
get_user_pages() can try to allocate a nearly unlimited amount of memory on
behalf of a user process, even if that process has been OOM killed.  The
OOM kill occurs upon return to user space via a SIGKILL, but
get_user_pages() will try allocate all its memory before returning.  Change
get_user_pages() to check for TIF_MEMDIE, and if set then return
immediately.

Signed-off-by: Ethan Solomita <solo@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:36 -07:00
Paul Mundt b71636e298 numa: mempolicy: dynamic interleave map for system init
This converts the default system init memory policy to use a dynamically
created node map instead of defaulting to all online nodes.  Nodes of a
certain size (>= 16MB) are judged to be suitable for interleave, and are added
to the map.  If all nodes are smaller in size, the largest one is
automatically selected.

Without this, tiny nodes find themselves out of memory before we even make it
to userspace.  Systems with large nodes will notice no change.

Only the system init policy is effected by this change, the regular
MPOL_DEFAULT policy is still switched to later on in the boot process as
normal.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:36 -07:00
Christoph Lameter f0630fff54 SLUB: support slub_debug on by default
Add a new configuration variable

CONFIG_SLUB_DEBUG_ON

If set then the kernel will be booted by default with slab debugging
switched on. Similar to CONFIG_SLAB_DEBUG. By default slab debugging
is available but must be enabled by specifying "slub_debug" as a
kernel parameter.

Also add support to switch off slab debugging for a kernel that was
built with CONFIG_SLUB_DEBUG_ON. This works by specifying

slub_debug=-

as a kernel parameter.

Dave Jones wanted this feature.
http://marc.info/?l=linux-kernel&m=118072189913045&w=2

[akpm@linux-foundation.org: clean up switch statement]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:36 -07:00
Andrew Morton fc9a07e7bf invalidate_mapping_pages(): add cond_resched
invalidate_mapping_pages() can sometimes take a long time (millions of pages
to free).  Long enough for the softlockup detector to trigger.

We used to have a cond_resched() in there but I took it out because the
drop_caches code calls invalidate_mapping_pages() under inode_lock.

The patch adds a nasty flag and puts the cond_resched() back.

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:36 -07:00
Nick Piggin 45426812d6 mm: debug check for the fault vs invalidate race
Add a bugcheck for Andrea's pagefault vs invalidate race.  This is triggerable
for both linear and nonlinear pages with a userspace test harness (using
direct IO and truncate, respectively).

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:35 -07:00
Joe Jin f96efd585b hugetlb: fix race in alloc_fresh_huge_page()
That static `nid' index needs locking.  Without it we can end up calling
alloc_pages_node() with an illegal node ID and the kernel crashes.

Acked-by: gurudas pai <gurudas.pai@oracle.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:35 -07:00
Anderson Briglia 2706a1b89b vmscan: fix comments related to shrink_list()
Fix the shrink_list name on some files under mm/ directory.

Signed-off-by: Anderson Briglia <anderson.briglia@indt.org.br>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:35 -07:00
Nick Piggin 553948491c slob: improved alignment handling
Remove the core slob allocator's minimum alignment restrictions, and instead
introduce the alignment restrictions at the slab API layer.  This lets us heed
the ARCH_KMALLOC/SLAB_MINALIGN directives, and also use __alignof__ (unsigned
long) for the default alignment (which should allow relaxed alignment
architectures to take better advantage of SLOB's small minimum alignment).

Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:35 -07:00
Nick Piggin d87a133fc2 slob: remove bigblock tracking
Remove the bigblock lists in favour of using compound pages and going directly
to the page allocator.  Allocation size is stored in page->private, which also
makes ksize more accurate than it previously was.

Saves ~.5K of code, and 12-24 bytes overhead per >= PAGE_SIZE allocation.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:35 -07:00
Nick Piggin 95b35127f1 slob: rework freelist handling
Improve slob by turning the freelist into a list of pages using struct page
fields, then each page has a singly linked freelist of slob blocks via a
pointer in the struct page.

- The first benefit is that the slob freelists can be indexed by a smaller
  type (2 bytes, if the PAGE_SIZE is reasonable).

- Next is that freeing is much quicker because it does not have to traverse
  the entire freelist. Allocation can be slightly faster too, because we can
  skip almost-full freelist pages completely.

- Slob pages are then freed immediately when they become empty, rather than
  having a periodic timer try to free them. This gives efficiency and memory
  consumption improvement.

Then, we don't encode seperate size and next fields into each slob block,
rather we use the sign bit to distinguish between "size" or "next". Then
size 1 blocks contain a "next" offset, and others contain the "size" in
the first unit and "next" in the second unit.

- This allows minimum slob allocation alignment to go from 8 bytes to 2
  bytes on 32-bit and 12 bytes to 2 bytes on 64-bit. In practice, it is
  best to align them to word size, however some architectures (eg. cris)
  could gain space savings from turning off this extra alignment.

Then, make kmalloc use its own slob_block at the front of the allocation
in order to encode allocation size, rather than rely on not overwriting
slob's existing header block.

- This reduces kmalloc allocation overhead similarly to alignment reductions.

- Decouples kmalloc layer from the slob allocator.

Then, add a page flag specific to slob pages.

- This means kfree of a page aligned slob block doesn't have to traverse
  the bigblock list.

I would get benchmarks, but my test box's network doesn't come up with
slob before this patch. I think something is timing out. Anyway, things
are faster after the patch.

Code size goes up about 1K, however dynamic memory usage _should_ be
lower even on relatively small memory systems.

Future todo item is to restore the cyclic free list search, rather than
to always begin at the start.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:35 -07:00
Eric Dumazet 1037b83bd0 MM: alloc_large_system_hash() can free some memory for non power-of-two bucketsize
alloc_large_system_hash() is called at boot time to allocate space for
several large hash tables.

Lately, TCP hash table was changed and its bucketsize is not a power-of-two
anymore.

On most setups, alloc_large_system_hash() allocates one big page (order >
0) with __get_free_pages(GFP_ATOMIC, order).  This single high_order page
has a power-of-two size, bigger than the needed size.

We can free all pages that wont be used by the hash table.

On a 1GB i386 machine, this patch saves 128 KB of LOWMEM memory.

TCP established hash table entries: 32768 (order: 6, 393216 bytes)

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:35 -07:00
Pavel Emelianov b92151bab9 Make /proc/slabinfo use seq_list_xxx helpers
This entry prints a header in .start callback.  This is OK, but the more
elegant solution would be to move this into the .show callback and use
seq_list_start_head() in .start one.

I have left it as is in order to make the patch just switch to new API and
noting more.

[adobriyan@sw.ru: Wrong pointer was used as kmem_cache pointer]
Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:35 -07:00
Rolf Eike Beer 68e116a3b5 MM: use DIV_ROUND_UP() in mm/memory.c
Replace a hand coded version of DIV_ROUND_UP().

Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:35 -07:00
Nishanth Aravamudan 31a5c6e4f2 hugetlb: remove unnecessary nid initialization
nid is initialized to numa_node_id() but will either be overwritten in
the loop or not used in the conditional. So remove the initialization.

Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:35 -07:00
KAMEZAWA Hiroyuki f0c0b2b808 change zonelist order: zonelist order selection logic
Make zonelist creation policy selectable from sysctl/boot option v6.

This patch makes NUMA's zonelist (of pgdat) order selectable.
Available order are Default(automatic)/ Node-based / Zone-based.

[Default Order]
The kernel selects Node-based or Zone-based order automatically.

[Node-based Order]
This policy treats the locality of memory as the most important parameter.
Zonelist order is created by each zone's locality. This means lower zones
(ex. ZONE_DMA) can be used before higher zone (ex. ZONE_NORMAL) exhausion.
IOW. ZONE_DMA will be in the middle of zonelist.
current 2.6.21 kernel uses this.

Pros.
 * A user can expect local memory as much as possible.
Cons.
 * lower zone will be exhansted before higher zone. This may cause OOM_KILL.

Maybe suitable if ZONE_DMA is relatively big and you never see OOM_KILL
because of ZONE_DMA exhaution and you need the best locality.

(example)
assume 2 node NUMA. node(0) has ZONE_DMA/ZONE_NORMAL, node(1) has ZONE_NORMAL.

*node(0)'s memory allocation order:

 node(0)'s NORMAL -> node(0)'s DMA -> node(1)'s NORMAL.

*node(1)'s memory allocation order:

 node(1)'s NORMAL -> node(0)'s NORMAL -> node(0)'s DMA.

[Zone-based order]
This policy treats the zone type as the most important parameter.
Zonelist order is created by zone-type order. This means lower zone
never be used bofere higher zone exhaustion.
IOW. ZONE_DMA will be always at the tail of zonelist.

Pros.
 * OOM_KILL(bacause of lower zone) occurs only if the whole zones are exhausted.
Cons.
 * memory locality may not be best.

(example)
assume 2 node NUMA. node(0) has ZONE_DMA/ZONE_NORMAL, node(1) has ZONE_NORMAL.

*node(0)'s memory allocation order:

 node(0)'s NORMAL -> node(1)'s NORMAL -> node(0)'s DMA.

*node(1)'s memory allocation order:

 node(1)'s NORMAL -> node(0)'s NORMAL -> node(0)'s DMA.

bootoption "numa_zonelist_order=" and proc/sysctl is supporetd.

command:
%echo N > /proc/sys/vm/numa_zonelist_order

Will rebuild zonelist in Node-based order.

command:
%echo Z > /proc/sys/vm/numa_zonelist_order

Will rebuild zonelist in Zone-based order.

Thanks to Lee Schermerhorn, he gives me much help and codes.

[Lee.Schermerhorn@hp.com: add check_highest_zone to build_zonelists_in_zone_order]
[akpm@linux-foundation.org: build fix]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Cc: "jesse.barnes@intel.com" <jesse.barnes@intel.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:35 -07:00
Eric Paris ed03218951 security: Protection for exploiting null dereference using mmap
Add a new security check on mmap operations to see if the user is attempting
to mmap to low area of the address space.  The amount of space protected is
indicated by the new proc tunable /proc/sys/vm/mmap_min_addr and defaults to
0, preserving existing behavior.

This patch uses a new SELinux security class "memprotect."  Policy already
contains a number of allow rules like a_t self:process * (unconfined_t being
one of them) which mean that putting this check in the process class (its
best current fit) would make it useless as all user processes, which we also
want to protect against, would be allowed. By taking the memprotect name of
the new class it will also make it possible for us to move some of the other
memory protect permissions out of 'process' and into the new class next time
we bump the policy version number (which I also think is a good future idea)

Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2007-07-11 22:52:29 -04:00
Paul Mackerras bf22f6fe2d Merge branch 'for-2.6.23' into merge 2007-07-11 13:28:26 +10:00
Carsten Otte d054fe3d10 xip sendfile removal
This patch removes xip_file_sendfile, the sendfile implementation for
xip without replacement. Those customers that use xip on s390 are not
using sendfile() as far as we know, and so far s390 is the only platform
this could potentially be used on so far.
Having sendfile is not a popular feature for execute in place file
systems, however we have a working implementation of splice_read() based
on fs/splice.c if anyone asks for it.
At this point in time, it does not seem preferable to merge
splice_read() for xip because it causes extra maintenence effort due to
code duplication and it requires struct page behind the xip memory
segment. We'd like to get rid of that in favor of supporting flash based
embedded platforms (Monta Vista work) soon.

Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-07-10 08:04:15 +02:00
Hugh Dickins ae97641646 shmem: convert to using splice instead of sendfile()
Remove shmem_file_sendfile and resurrect shmem_readpage, as used by tmpfs
to support loop and sendfile in 2.4 and 2.5.  Now tmpfs can support splice,
loop and sendfile in the simplest way, using generic_file_splice_read and
generic_file_splice_write (with the aid of shmem_prepare_write).

We could make some efficiency tweaks later, if there's a real need;
but this is stable and works well as is.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-07-10 08:04:15 +02:00
Jens Axboe 0452a4e5d0 sendfile: kill generic_file_sendfile()
It's no longer used.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-07-10 08:04:14 +02:00
Peter Zijlstra 4e99325b46 mm: double mark_page_accessed() in read_cache_page_async()
Fix a post-2.6.21 regression.

read_cache_page_async() has two invocations of mark_page_accessed() which will
launch pages right onto the active list.

Remove the first one, keeping the latter one.  This avoids marking unwanted
pages active (in the retry loop).

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-08 10:13:21 -07:00
Christoph Lameter d23cf676d0 slub: remove useless EXPORT_SYMBOL
kmem_cache_open is static. EXPORT_SYMBOL was leftover from some earlier
time period where kmem_cache_open was usable outside of slub.

(Fixes powerpc build error)

Signed-off-by: Chrsitoph Lameter <clameter@sgi.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-06 11:45:11 -07:00
Peter Zijlstra 23c1fb5296 mm: fixup /proc/vmstat output
Line up the vmstat_text with zone_stat_item

enum zone_stat_item {
	/* First 128 byte cacheline (assuming 64 bit words) */
	NR_FREE_PAGES,
	NR_INACTIVE,
	NR_ACTIVE,

We current have nr_active and nr_inactive reversed.

[ "OK with patch, though using initializers canbe handy to prevent such
   things in future:

	static const char * const vmstat_text[] = {
		[NR_FREE_PAGES] = "nr_free_pages",
		..."
							 - Alexey ]

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-06 10:26:50 -07:00
David Woodhouse 87a927c715 Fix slab redzone alignment
Commit b46b8f19c9 fixed a couple of bugs
by switching the redzone to 64 bits. Unfortunately, it neglected to
ensure that the _second_ redzone, after the slab object, is aligned
correctly. This caused illegal instruction faults on sparc32, which for
some reason not entirely clear to me are not trapped and fixed up.

Two things need to be done to fix this:
  - increase the object size, rounding up to alignof(long long) so
    that the second redzone can be aligned correctly.
  - If SLAB_STORE_USER is set but alignof(long long)==8, allow a
    full 64 bits of space for the user word at the end of the buffer,
    even though we may not _use_ the whole 64 bits.

This patch should be a no-op on any 64-bit architecture or any 32-bit
architecture where alignof(long long) == 4. Of the others, it's tested
on ppc32 by myself and a very similar patch was tested on sparc32 by
Mark Fortescue, who reported the new problem.

Also, fix the conditions for FORCED_DEBUG, which hadn't been adjusted to
the new sizes. Again noticed by Mark.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-05 15:54:13 -07:00
Christoph Lameter dbc55faa64 SLUB: Make lockdep happy by not calling add_partial with interrupts enabled during bootstrap
If we move the local_irq_enable() to the end of the function then
add_partial() in early_kmem_cache_node_alloc() will be called
with interrupts disabled like during regular operations.

This makes lockdep happy.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Tested-by: Andre Noll <maan@systemlinux.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-03 13:56:13 -07:00
Christoph Lameter 17022220dd SLAB: remove WARN_ON_ONCE for zero sized objects for 2.6.22 release
We agreed to remove the WARN_ON_ONCE before 2.6.22 is released.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-01 12:29:43 -07:00
Hugh Dickins 30acbabae3 mm: kill validate_anon_vma to avoid mapcount BUG
validate_anon_vma gave a useful check on the integrity of the anon_vma list
when Andrea was developing obj rmap; but it was not enabled in SLES9
itself, nor in mainline, until Nick changed commented-out RMAP_DEBUG to
configurable CONFIG_DEBUG_VM in 2.6.17.  Now Petr Vandrovec reports that
its BUG_ON(mapcount > 100000) can easily crash a CONFIG_DEBUG_VM=y system.

That limit was just an arbitrary number to protect against an infinite
loop.  We could raise it to something enormous (depending on sizeof struct
vma and size of memory?); but I rather think validate_anon_vma has outlived
its usefulness, and is better just removed - which gives a magnificent
performance boost to anything like Petr's test program ;)

Of course, a very long anon_vma list is bad news for preemption latency,
and I believe there has been one recent report of such: let's not forget
that, but validate_anon_vma only makes it worse not better.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Petr Vandrovec <petr@vmware.com>
Acked-by: Nick Piggin <npiggin@suse.de>
Cc: Andrea Arcangeli <andrea@suse.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-28 11:34:53 -07:00
Christoph Lameter 8496634302 SLUB: fix behavior if the text output of list_locations overflows PAGE_SIZE
If slabs are allocated or freed from a large set of call sites (typical for
the kmalloc area) then we may create more output than fits into a single
PAGE and sysfs only gives us one page.  The output should be truncated.
This patch fixes the checks to do the truncation properly.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-24 08:59:11 -07:00
Helge Deller 06b32f3ab6 [PARISC] Handle wrapping in expand_upwards()
Function expand_upwards() did not guarded against wrapping
around to address 0. This fixes the adjtimex02 testcase from
the Linux Test Project on a 32bit PARISC kernel.

[expand_upwards is only used on parisc and ia64; it looks like it does
 the right thing on both. --kyle]

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2007-06-21 17:46:20 -04:00
Christoph Lameter 4b356be019 SLUB: minimum alignment fixes
If ARCH_KMALLOC_MINALIGN is set to a value greater than 8 (SLUBs smallest
kmalloc cache) then SLUB may generate duplicate slabs in sysfs (yes again)
because the object size is padded to reach ARCH_KMALLOC_MINALIGN.  Thus the
size of the small slabs is all the same.

No arch sets ARCH_KMALLOC_MINALIGN larger than 8 though except mips which
for some reason wants a 128 byte alignment.

This patch increases the size of the smallest cache if
ARCH_KMALLOC_MINALIGN is greater than 8.  In that case more and more of the
smallest caches are disabled.

If we do that then the count of the active general caches that is displayed
on boot is not correct anymore since we may skip elements of the kmalloc
array.  So count them separately.

This approach was tested by Havard yesterday.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-16 13:16:16 -07:00
Benjamin Herrenschmidt 8dab5241d0 Rework ptep_set_access_flags and fix sun4c
Some changes done a while ago to avoid pounding on ptep_set_access_flags and
update_mmu_cache in some race situations break sun4c which requires
update_mmu_cache() to always be called on minor faults.

This patch reworks ptep_set_access_flags() semantics, implementations and
callers so that it's now responsible for returning whether an update is
necessary or not (basically whether the PTE actually changed).  This allow
fixing the sparc implementation to always return 1 on sun4c.

[akpm@linux-foundation.org: fixes, cleanups]
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: David Miller <davem@davemloft.net>
Cc: Mark Fortescue <mark@mtfhpc.demon.co.uk>
Acked-by: William Lee Irwin III <wli@holomorphy.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-16 13:16:16 -07:00
Christoph Lameter dd08c40e3e SLUB slab validation: Alloc while interrupts are disabled must use GFP_ATOMIC
The data structure to manage the information gathered about functions
allocating and freeing objects is allocated when the list_lock has already
been taken.  We need to allocate with GFP_ATOMIC instead of GFP_KERNEL.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-16 13:16:15 -07:00
Paul Mundt d09c6b8094 mm: Fix memory/cpu hotplug section mismatch and oops.
When building with memory hotplug enabled and cpu hotplug disabled, we
end up with the following section mismatch:

WARNING: mm/built-in.o(.text+0x4e58): Section mismatch: reference to
.init.text: (between 'free_area_init_node' and '__build_all_zonelists')

This happens as a result of:

        -> free_area_init_node()
          -> free_area_init_core()
            -> zone_pcp_init() <-- all __meminit up to this point
              -> zone_batchsize() <-- marked as __cpuinit                     fo

This happens because CONFIG_HOTPLUG_CPU=n sets __cpuinit to __init, but
CONFIG_MEMORY_HOTPLUG=y unsets __meminit.

Changing zone_batchsize() to __devinit fixes this.

__devinit is the only thing that is common between CONFIG_HOTPLUG_CPU=y and
CONFIG_MEMORY_HOTPLUG=y. In the long run, perhaps this should be moved to
another section identifier completely. Without this, memory hot-add
of offline nodes (via hotadd_new_pgdat()) will oops if CPU hotplug is
not also enabled.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

--

 mm/page_alloc.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
2007-06-15 16:18:08 -07:00
Benjamin Herrenschmidt c19c03fc74 [POWERPC] unmap_vm_area becomes unmap_kernel_range for the public
This makes unmap_vm_area static and a wrapper around a new
exported unmap_kernel_range that takes an explicit range instead
of a vm_area struct.

This makes it more versatile for code that wants to play with kernel
page tables outside of the standard vmalloc area.

(One example is some rework of the PowerPC PCI IO space mapping
code that depends on that patch and removes some code duplication
and horrible abuse of forged struct vm_struct).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-06-14 22:29:56 +10:00
Stephen Rothwell 193faea928 Move three functions that are only needed for CONFIG_MEMORY_HOTPLUG
into the appropriate #ifdef.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-08 17:23:33 -07:00
Christoph Lameter 272c1d21d6 SLUB: return ZERO_SIZE_PTR for kmalloc(0)
Instead of returning the smallest available object return ZERO_SIZE_PTR.

A ZERO_SIZE_PTR can be legitimately used as an object pointer as long as it
is not deferenced.  The dereference of ZERO_SIZE_PTR causes a distinctive
fault.  kfree can handle a ZERO_SIZE_PTR in the same way as NULL.

This enables functions to use zero sized object. e.g. n = number of objects.

	objects = kmalloc(n * sizeof(object));

	for (i = 0; i < n; i++)
		objects[i].x = y;

	kfree(objects);

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-08 17:23:33 -07:00
Christoph Lameter 3cdc0ed0ce slab: fix alien cache handling
cache_free_alien must be called regardless if we use alien caches or not.
cache_free_alien() will do the right thing if there are no alien caches
available.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Acked-by: Pekka J Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-08 17:23:32 -07:00
Hugh Dickins a210906c1b mount -t tmpfs -o mpol=: check nodes online
Randy Dunlap reports that a tmpfs, mounted with NUMA mpol= specifying an
offline node, crashes as soon as data is allocated upon it.  Now restrict it
to online nodes, where before it restricted to MAX_NUMNODES.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Robin Holt <holt@sgi.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Tested-and-acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-08 17:23:32 -07:00
Paul Mundt 33d63bd83b sh: memory hot-add for sparsemem users support.
This enables simple hotplug support for sparsemem users. Presently
this only permits memory being added in to node 0 on ZONE_NORMAL.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-06-08 02:43:51 +00:00
Christoph Lameter 27390bc335 SLUB: fix locking for hotplug callbacks
Hotplug callbacks are performed with interrupts enabled.  Slub requires
interrupts to be disabled for flushing caches.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-01 08:18:30 -07:00
Yasunori Goto 13466c8419 memory hotplug: fix unnecessary calling of init_currenty_empty_zone()
zone->present_pages is updated in online_pages().  But, __add_zone() can be
called twice or more before calling online_pages().  So,
init_currenty_empty_zone() can be called unnecessary times.  It is cause of
memory leak of zone's wait_table.

Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-01 08:18:29 -07:00
Zou Nan hai 2e1c49db4c x86_64: allocate sparsemem memmap above 4G
On systems with huge amount of physical memory, VFS cache and memory memmap
may eat all available system memory under 4G, then the system may fail to
allocate swiotlb bounce buffer.

There was a fix for this issue in arch/x86_64/mm/numa.c, but that fix dose
not cover sparsemem model.

This patch add fix to sparsemem model by first try to allocate memmap above
4G.

Signed-off-by: Zou Nan hai <nanhai.zou@intel.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-01 08:18:27 -07:00
Roman Zippel 12d810c1b8 m68k: discontinuous memory support
Fix support for discontinuous memory

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-31 07:58:14 -07:00
Christoph Lameter 8ffa68755a SLUB: Fix NUMA / SYSFS bootstrap issue
We need this patch in ASAP.  Patch fixes the mysterious hang that remained
on some particular configurations with lockdep on after the first fix that
moved the #idef CONFIG_SLUB_DEBUG to the right location.  See
http://marc.info/?t=117963072300001&r=1&w=2

The kmem_cache_node cache is very special because it is needed for NUMA
bootstrap.  Under certain conditions (like for example if lockdep is
enabled and significantly increases the size of spinlock_t) the structure
may become exactly the size as one of the larger caches in the kmalloc
array.

That early during bootstrap we cannot perform merging properly.  The unique
id for the kmem_cache_node cache will match one of the kmalloc array.
Sysfs will complain about a duplicate directory entry.  All of this occurs
while the console is not yet fully operational.  Thus boot may appear to be
silently failing.

The kmem_cache_node cache is very special.  During early boostrap the main
allocation function is not operational yet and so we have to run our own
small special alloc function during early boot.  It is also special in that
it is never freed.

We really do not want any merging on that cache.  Set the refcount -1 and
forbid merging of slabs that have a negative refcount.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-31 07:58:14 -07:00
Christoph Lameter 33e9e24101 SLUB Debug: fix check for super sized slabs (>512k 64bit, >256k 32bit)
The check for super sized slabs where we can no longer move the free
pointer behind the object for debugging purposes etc is accessing a
field that is not setup yet.  We must use objsize here since the size of
the slab has not been determined yet.

The effect of this is that a global slab shrink via "slabinfo -s" will
show errors about offsets being wrong if booted with slub_debug.
Potentially there are other troubles with huge slabs under slub_debug
because the calculated free pointer offset is truncated.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-23 20:14:13 -07:00
Miklos Szeredi 418508c132 fix unused setup_nr_node_ids
mm/page_alloc.c:931: warning: 'setup_nr_node_ids' defined but not used

This is now the only (!) compiler warning I get in my UML build :)

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-23 20:14:13 -07:00
Christoph Lameter c12b3c6251 SLUB Debug: Fix object size calculation
The object size calculation is wrong if !CONFIG_SLUB_DEBUG because the
#ifdef CONFIG_SLUB_DEBUG is now switching off the size adjustments for
DESTROY_BY_RCU and ctor.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Acked-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-23 20:14:11 -07:00
Linus Torvalds 080e89270a Merge git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-fix
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-fix:
  mm/slab: fix section mismatch warning
  mm: fix section mismatch warnings
  init/main: use __init_refok to fix section mismatch
  kbuild: introduce __init_refok/__initdata_refok to supress section mismatch warnings
  all-archs: consolidate .data section definition in asm-generic
  all-archs: consolidate .text section definition in asm-generic
  kbuild: add "Section mismatch" warning whitelist for powerpc
  kbuild: make better section mismatch reports on i386, arm and mips
  kbuild: make modpost section warnings clearer
  kconfig: search harder for curses library in check-lxdialog.sh
  kbuild: include limits.h in sumversion.c for PATH_MAX
  powerpc: Fix the MODALIAS generation in modpost for of devices
2007-05-21 12:03:04 -07:00
Alexey Dobriyan e8edc6e03a Detach sched.h from mm.h
First thing mm.h does is including sched.h solely for can_do_mlock() inline
function which has "current" dereference inside. By dealing with can_do_mlock()
mm.h can be detached from sched.h which is good. See below, why.

This patch
a) removes unconditional inclusion of sched.h from mm.h
b) makes can_do_mlock() normal function in mm/mlock.c
c) exports can_do_mlock() to not break compilation
d) adds sched.h inclusions back to files that were getting it indirectly.
e) adds less bloated headers to some files (asm/signal.h, jiffies.h) that were
   getting them indirectly

Net result is:
a) mm.h users would get less code to open, read, preprocess, parse, ... if
   they don't need sched.h
b) sched.h stops being dependency for significant number of files:
   on x86_64 allmodconfig touching sched.h results in recompile of 4083 files,
   after patch it's only 3744 (-8.3%).

Cross-compile tested on

	all arm defconfigs, all mips defconfigs, all powerpc defconfigs,
	alpha alpha-up
	arm
	i386 i386-up i386-defconfig i386-allnoconfig
	ia64 ia64-up
	m68k
	mips
	parisc parisc-up
	powerpc powerpc-up
	s390 s390-up
	sparc sparc-up
	sparc64 sparc64-up
	um-x86_64
	x86_64 x86_64-up x86_64-defconfig x86_64-allnoconfig

as well as my two usual configs.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-21 09:18:19 -07:00
Sam Ravnborg 38bdc32af4 mm/slab: fix section mismatch warning
Use the new __init_refok marker to avoid the
section mismatch warning from slab.c

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2007-05-19 09:11:58 +02:00
Sam Ravnborg 577a32f620 mm: fix section mismatch warnings
modpost had two cases hardcoded for mm/
Shift over to __init_refok and kill the
hardcoded function names in modpost.

This has the drawback that the functions
will always be kept no matter configuration.
With previous code the function were placed in
init section if configuration allowed it.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2007-05-19 09:11:58 +02:00
Nick Piggin c97a9e10ea mm: more rmap checking
Re-introduce rmap verification patches that Hugh removed when he removed
PG_map_lock. PG_map_lock actually isn't needed to synchronise access to
anonymous pages, because PG_locked and PTL together already do.

These checks were important in discovering and fixing a rare rmap corruption
in SLES9.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-17 05:23:06 -07:00
Benjamin Herrenschmidt d55e2ca873 Make __vunmap static
__vunmap doesn't seem to be used outside of mm/vmalloc.c, and has
no prototype in any header so let's make it static

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-17 05:23:04 -07:00
Christoph Lameter 0aa817f078 Slab allocators: define common size limitations
Currently we have a maze of configuration variables that determine the
maximum slab size.  Worst of all it seems to vary between SLAB and SLUB.

So define a common maximum size for kmalloc.  For conveniences sake we use
the maximum size ever supported which is 32 MB.  We limit the maximum size
to a lower limit if MAX_ORDER does not allow such large allocations.

For many architectures this patch will have the effect of adding large
kmalloc sizes.  x86_64 adds 5 new kmalloc sizes.  So a small amount of
memory will be needed for these caches (contemporary SLAB has dynamically
sizeable node and cpu structure so the waste is less than in the past)

Most architectures will then be able to allocate object with sizes up to
MAX_ORDER.  We have had repeated breakage (in fact whenever we doubled the
number of supported processors) on IA64 because one or the other struct
grew beyond what the slab allocators supported.  This will avoid future
issues and f.e.  avoid fixes for 2k and 4k cpu support.

CONFIG_LARGE_ALLOCS is no longer necessary so drop it.

It fixes sparc64 with SLAB.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-17 05:23:04 -07:00
Christoph Lameter 3ec0974210 SLUB: Simplify debug code
Consolidate functionality into the #ifdef section.

Extract tracing into one subroutine.

Move object debug processing into the #ifdef section so that the
code in __slab_alloc and __slab_free becomes minimal.

Reduce number of functions we need to provide stubs for in the !SLUB_DEBUG case.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-17 05:23:04 -07:00
Christoph Lameter a35afb830f Remove SLAB_CTOR_CONSTRUCTOR
SLAB_CTOR_CONSTRUCTOR is always specified. No point in checking it.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@ucw.cz>
Cc: David Chinner <dgc@sgi.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-17 05:23:04 -07:00
Christoph Lameter 5577bd8a85 SLUB: Do our own flags based on PG_active and PG_error
The atomicity when handling flags in SLUB is not necessary since both flags
used by SLUB are not updated in a racy way.  Flag updates are either done
during slab creation or destruction or under slab_lock.  Some of these flags
do not have the non atomic variants that we need.  So define our own.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-17 05:23:03 -07:00
Christoph Lameter 0b44f7a5b5 slab: warn on zero-length allocations
slub warns on this, and we're working on making kmalloc(0) return NULL.
Let's make slab warn as well so our testers detect such callers more
rapidly.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-17 05:23:03 -07:00
Christoph Lameter 4b6f075045 SLUB: Define functions for cpu slab handling instead of using PageActive
Use inline functions to access the per cpu bit.  Intoduce the notion of
"freezing" a slab to make things more understandable.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-17 05:23:03 -07:00
Christoph Lameter c59def9f22 Slab allocators: Drop support for destructors
There is no user of destructors left.  There is no reason why we should keep
checking for destructors calls in the slab allocators.

The RFC for this patch was discussed at
http://marc.info/?l=linux-kernel&m=117882364330705&w=2

Destructors were mainly used for list management which required them to take a
spinlock.  Taking a spinlock in a destructor is a bit risky since the slab
allocators may run the destructors anytime they decide a slab is no longer
needed.

Patch drops destructor support.  Any attempt to use a destructor will BUG().

Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-17 05:23:03 -07:00
Nick Piggin afc0cedbe9 slob: implement RCU freeing
The SLOB allocator should implement SLAB_DESTROY_BY_RCU correctly, because
even on UP, RCU freeing semantics are not equivalent to simply freeing
immediately.  This also allows SLOB to be used on SMP.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-17 05:23:02 -07:00
Christoph Lameter 43c0f3d25c Fix: find_or_create_page skips cpuset memory spreading.
We call alloc_page where we should be calling __page_cache_alloc.

__page_cache_alloc performs cpuset memory spreading.  alloc_page does not.
There is no reason that pages allocated via find_or_create should be
exempt.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-16 21:19:15 -07:00
Hugh Dickins 1800782016 slub: don't confuse ctor and dtor
kmem_cache_create() was swapping ctor and dtor in calling find_mergeable():
though it caused no bug, and probably never would, even if destructors are
retained; but fix it so as not to generate anxiety ;)

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-16 21:19:15 -07:00
Paul Mundt 6c645ac725 sh64: generic quicklist support.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-05-14 09:55:35 +09:00
Miklos Szeredi 0ea9718016 consolidate generic_writepages and mpage_writepages
Clean up massive code duplication between mpage_writepages() and
generic_writepages().

The new generic function, write_cache_pages() takes a function pointer
argument, which will be called for each page to be written.

Maybe cifs_writepages() too can use this infrastructure, but I'm not
touching that with a ten-foot pole.

The upcoming page writeback support in fuse will also want this.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-11 08:29:35 -07:00
Christoph Lameter 39bf6270f5 VM statistics: Make timer deferrable
VM statistics updates do not matter if the kernel is in idle powersaving
mode.  So allow the timer to be deferred.

It would be better though if we could switch the timer between deferrable
and nondeferrable based on differentials present.  The timer would start
out nondeferrable and if we find that there were no updates in the last
statistics interval then we would switch the timer to deferrable.  If the
timer later finds again that there are differentials then go to
nondeferrable again.

And yet another way would be to run the timer shortly before going to idle?

The solution here means that the VM counters may be slightly off during
idle since differentials may be still pending while the timer is deferred.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-11 08:29:32 -07:00
Mika Kukkonen 7faaa5f0bf Bug in mm/thrash.c function grab_swap_token()
Following bug was uncovered by compiling with '-W' flag:

  CC      mm/thrash.o
mm/thrash.c: In function ‘grab_swap_token’:
mm/thrash.c:52: warning: comparison of unsigned expression < 0 is always false

Variable token_priority is unsigned, so decrementing first and then
checking the result does not work; fixed by reversing the test, patch
attached (compile tested only).

I am not sure if likely() makes much sense in this new situation, but
I'll let somebody else to make a decision on that.

Signed-off-by: Mika Kukkonen <mikukkon@iki.fi>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-11 08:29:32 -07:00
Christoph Lameter bcf889f965 SLUB: remove nr_cpu_ids hack
This was in SLUB in order to head off trouble while the nr_cpu_ids
functionality was not merged.  Its merged now so no need to still have this.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-10 09:26:53 -07:00
Stephen Rothwell 6f076f5dd9 early_pfn_to_nid needs to be __meminit
Since it is referenced by memmap_init_zone (which is __meminit) via the
early_pfn_in_nid macro when CONFIG_NODES_SPAN_OTHER_NODES is set (which
basically means PowerPC 64).

This removes a section mismatch warning in those circumstances.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-10 09:26:52 -07:00
Christoph Lameter 894b8788d7 slub: support concurrent local and remote frees and allocs on a slab
Avoid atomic overhead in slab_alloc and slab_free

SLUB needs to use the slab_lock for the per cpu slabs to synchronize with
potential kfree operations.  This patch avoids that need by moving all free
objects onto a lockless_freelist.  The regular freelist continues to exist
and will be used to free objects.  So while we consume the
lockless_freelist the regular freelist may build up objects.

If we are out of objects on the lockless_freelist then we may check the
regular freelist.  If it has objects then we move those over to the
lockless_freelist and do this again.  There is a significant savings in
terms of atomic operations that have to be performed.

We can even free directly to the lockless_freelist if we know that we are
running on the same processor.  So this speeds up short lived objects.
They may be allocated and freed without taking the slab_lock.  This is
particular good for netperf.

In order to maximize the effect of the new faster hotpath we extract the
hottest performance pieces into inlined functions.  These are then inlined
into kmem_cache_alloc and kmem_cache_free.  So hotpath allocation and
freeing no longer requires a subroutine call within SLUB.

[I am not sure that it is worth doing this because it changes the easy to
read structure of slub just to reduce atomic ops.  However, there is
someone out there with a benchmark on 4 way and 8 way processor systems
that seems to show a 5% regression vs.  Slab.  Seems that the regression is
due to increased atomic operations use vs.  SLAB in SLUB).  I wonder if
this is applicable or discernable at all in a real workload?]

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-10 09:26:52 -07:00
Linus Torvalds d84c4124c4 Merge master.kernel.org:/pub/scm/linux/kernel/git/lethal/sh-2.6
* master.kernel.org:/pub/scm/linux/kernel/git/lethal/sh-2.6:
  sh: Fix stacktrace simplification fallout.
  sh: SH7760 DMABRG support.
  sh: clockevent/clocksource/hrtimers/nohz TMU support.
  sh: Truncate MAX_ACTIVE_REGIONS for the common case.
  rtc: rtc-sh: Fix rtc_dev pointer for rtc_update_irq().
  sh: Convert to common die chain.
  sh: Wire up utimensat syscall.
  sh: landisk mv_nr_irqs definition.
  sh: Fixup ndelay() xloops calculation for alternate HZ.
  sh: Add 32-bit opcode feature CPU flag.
  sh: Fix PC adjustments for varying opcode length.
  sh: Support for SH-2A 32-bit opcodes.
  sh: Kill off redundant __div64_32 symbol export.
  sh: Share exception vector table for SH-3/4.
  sh: Always define TRAPA_BUG_OPCODE.
  sh: __GFP_REPEAT for pte allocations, too.
  rtc: rtc-sh: Fix up dev_dbg() warnings.
  sh: generic quicklist support.
2007-05-09 13:08:20 -07:00
David Howells c855ff3718 Fix a bad error case handling in read_cache_page_async()
Commit 6fe6900e1e introduced a nasty bug
in read_cache_page_async().

It added a "mark_page_accessed(page)" at the final return path in
read_cache_page_async().  But in error cases, 'page' holds the error
code, and you can't mark it accessed.

[ and Glauber de Oliveira Costa points out that we can use a return
  instead of adding more goto's ]

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 13:04:03 -07:00
Linus Torvalds 9a9136e270 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial
* git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial: (25 commits)
  sound: convert "sound" subdirectory to UTF-8
  MAINTAINERS: Add cxacru website/mailing list
  include files: convert "include" subdirectory to UTF-8
  general: convert "kernel" subdirectory to UTF-8
  documentation: convert the Documentation directory to UTF-8
  Convert the toplevel files CREDITS and MAINTAINERS to UTF-8.
  remove broken URLs from net drivers' output
  Magic number prefix consistency change to Documentation/magic-number.txt
  trivial: s/i_sem /i_mutex/
  fix file specification in comments
  drivers/base/platform.c: fix small typo in doc
  misc doc and kconfig typos
  Remove obsolete fat_cvf help text
  Fix occurrences of "the the "
  Fix minor typoes in kernel/module.c
  Kconfig: Remove reference to external mqueue library
  Kconfig: A couple of grammatical fixes in arch/i386/Kconfig
  Correct comments in genrtc.c to refer to correct /proc file.
  Fix more "deprecated" spellos.
  Fix "deprecated" typoes.
  ...

Fix trivial comment conflict in kernel/relay.c.
2007-05-09 12:54:17 -07:00
Christoph Lameter 4037d45220 Move remote node draining out of slab allocators
Currently the slab allocators contain callbacks into the page allocator to
perform the draining of pagesets on remote nodes.  This requires SLUB to have
a whole subsystem in order to be compatible with SLAB.  Moving node draining
out of the slab allocators avoids a section of code in SLUB.

Move the node draining so that is is done when the vm statistics are updated.
At that point we are already touching all the cachelines with the pagesets of
a processor.

Add a expire counter there.  If we have to update per zone or global vm
statistics then assume that the pageset will require subsequent draining.

The expire counter will be decremented on each vm stats update pass until it
reaches zero.  Then we will drain one batch from the pageset.  The draining
will cause vm counter updates which will then cause another expiration until
the pcp is empty.  So we will drain a batch every 3 seconds.

Note that remote node draining is a somewhat esoteric feature that is required
on large NUMA systems because otherwise significant portions of system memory
can become trapped in pcp queues.  The number of pcp is determined by the
number of processors and nodes in a system.  A system with 4 processors and 2
nodes has 8 pcps which is okay.  But a system with 1024 processors and 512
nodes has 512k pcps with a high potential for large amount of memory being
caught in them.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:56 -07:00
Christoph Lameter 77461ab332 Make vm statistics update interval configurable
Make it configurable.  Code in mm makes the vm statistics intervals
independent from the cache reaper use that opportunity to make it
configurable.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:56 -07:00
Christoph Lameter d1187ed210 vmstat: use our own timer events
vmstat is currently using the cache reaper to periodically bring the
statistics up to date.  The cache reaper does only exists in SLUB as a way to
provide compatibility with SLAB.  This patch removes the vmstat calls from the
slab allocators and provides its own handling.

The advantage is also that we can use a different frequency for the updates.
Refreshing vm stats is a pretty fast job so we can run this every second and
stagger this by only one tick.  This will lead to some overlap in large
systems.  F.e a system running at 250 HZ with 1024 processors will have 4 vm
updates occurring at once.

However, the vm stats update only accesses per node information.  It is only
necessary to stagger the vm statistics updates per processor in each node.  Vm
counter updates occurring on distant nodes will not cause cacheline
contention.

We could implement an alternate approach that runs the first processor on each
node at the second and then each of the other processor on a node on a
subsequent tick.  That may be useful to keep a large amount of the second free
of timer activity.  Maybe the timer folks will have some feedback on this one?

[jirislaby@gmail.com: add missing break]
Cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:56 -07:00
Rafael J. Wysocki 8bb7844286 Add suspend-related notifications for CPU hotplug
Since nonboot CPUs are now disabled after tasks and devices have been
frozen and the CPU hotplug infrastructure is used for this purpose, we need
special CPU hotplug notifications that will help the CPU-hotplug-aware
subsystems distinguish normal CPU hotplug events from CPU hotplug events
related to a system-wide suspend or resume operation in progress.  This
patch introduces such notifications and causes them to be used during
suspend and resume transitions.  It also changes all of the
CPU-hotplug-aware subsystems to take these notifications into consideration
(for now they are handled in the same way as the corresponding "normal"
ones).

[oleg@tv-sign.ru: cleanups]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:56 -07:00
Nate Diller 01f2705daf fs: convert core functions to zero_user_page
It's very common for file systems to need to zero part or all of a page,
the simplist way is just to use kmap_atomic() and memset().  There's
actually a library function in include/linux/highmem.h that does exactly
that, but it's confusingly named memclear_highpage_flush(), which is
descriptive of *how* it does the work rather than what the *purpose* is.
So this patchset renames the function to zero_user_page(), and calls it
from the various places that currently open code it.

This first patch introduces the new function call, and converts all the
core kernel callsites, both the open-coded ones and the old
memclear_highpage_flush() ones.  Following this patch is a series of
conversions for each file system individually, per AKPM, and finally a
patch deprecating the old call.  The diffstat below shows the entire
patchset.

[akpm@linux-foundation.org: fix a few things]
Signed-off-by: Nate Diller <nate.diller@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:55 -07:00
Christoph Lameter 5830c59021 slab: shut down cache_reaper when cpu goes down
Shutdown the cache_reaper if the cpu is brought down and set the
cache_reap.func to NULL.  Otherwise hotplug shuts down the reaper for good.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:53 -07:00
Heiko Carstens 38c3bd96a0 slab: use CPU_LOCK_[ACQUIRE|RELEASE]
Looks like this was forgotten when CPU_LOCK_[ACQUIRE|RELEASE] was
introduced.

Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: Gautham Shenoy <ego@in.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:51 -07:00
David Howells ef71c15c46 AFS: export a couple of core functions for AFS write support
Export a couple of core functions for AFS write support to use:

	find_get_pages_contig()
	find_get_pages_tag()

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:50 -07:00
Ken Chen 8a63011275 pretend cpuset has some form of hugetlb page reservation
When cpuset is configured, it breaks the strict hugetlb page reservation as
the accounting is done on a global variable.  Such reservation is
completely rubbish in the presence of cpuset because the reservation is not
checked against page availability for the current cpuset.  Application can
still potentially OOM'ed by kernel with lack of free htlb page in cpuset
that the task is in.  Attempt to enforce strict accounting with cpuset is
almost impossible (or too ugly) because cpuset is too fluid that task or
memory node can be dynamically moved between cpusets.

The change of semantics for shared hugetlb mapping with cpuset is
undesirable.  However, in order to preserve some of the semantics, we fall
back to check against current free page availability as a best attempt and
hopefully to minimize the impact of changing semantics that cpuset has on
hugetlb.

Signed-off-by: Ken Chen <kenchen@google.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:49 -07:00
Ken Chen ace4bd29c2 fix leaky resv_huge_pages when cpuset is in use
The internal hugetlb resv_huge_pages variable can permanently leak nonzero
value in the error path of hugetlb page fault handler when hugetlb page is
used in combination of cpuset.  The leaked count can permanently trap N
number of hugetlb pages in unusable "reserved" state.

Steps to reproduce the bug:

  (1) create two cpuset, user1 and user2
  (2) reserve 50 htlb pages in cpuset user1
  (3) attempt to shmget/shmat 50 htlb page inside cpuset user2
  (4) kernel oom the user process in step 3
  (5) ipcrm the shm segment

At this point resv_huge_pages will have a count of 49, even though
there are no active hugetlbfs file nor hugetlb shared memory segment
in the system.  The leak is permanent and there is no recovery method
other than system reboot. The leaked count will hold up all future use
of that many htlb pages in all cpusets.

The culprit is that the error path of alloc_huge_page() did not
properly undo the change it made to resv_huge_page, causing
inconsistent state.

Signed-off-by: Ken Chen <kenchen@google.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Adam Litke <agl@us.ibm.com>
Cc: Martin Bligh <mbligh@google.com>
Acked-by: David Gibson <dwg@au1.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:48 -07:00
Pekka J Enberg 7ae439ce0c krealloc: fix kerneldoc comments
No "blank" (or "*") line is allowed between the function name and lines for
it parameter(s).

Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:46 -07:00
Christoph Lameter 5e6d444ea1 SLUB: rework slab order determination
In some cases SLUB is creating uselessly slabs that are larger than
slub_max_order. Also the layout of some of the slabs was not satisfactory.

Go to an iterarive approach.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:46 -07:00
Christoph Lameter 45edfa580b SLUB: include lifetime stats and sets of cpus / nodes in tracking output
We have information about how long an object existed and about the nodes and
cpus where the allocations and frees took place.  Add that information to the
tracking output in /sys/slab/xx/alloc_calls and /sys/slab/free_calls

This will then enable slabinfo to output nice reports like this:

  christoph@qirst:~/slub$ ./slabinfo kmalloc-128

  Slabcache: kmalloc-128           Aliases:  0 Order :  0

  Sizes (bytes)     Slabs              Debug                Memory
  ------------------------------------------------------------------------
  Object :     128  Total  :      12   Sanity Checks : On   Total:   49152
  SlabObj:     200  Full   :       7   Redzoning     : On   Used :   24832
  SlabSiz:    4096  Partial:       4   Poisoning     : On   Loss :   24320
  Loss   :      72  CpuSlab:       1   Tracking      : On   Lalig:   13968
  Align  :       8  Objects:      20   Tracing       : Off  Lpadd:    1152

  kmalloc-128 has no kmem_cache operations

  kmalloc-128: Kernel object allocation
  -----------------------------------------------------------------------
        6 param_sysfs_setup+0x71/0x130 age=284512/284512/284512 pid=1 nodes=0-1,3
       11 percpu_populate+0x39/0x80 age=283914/284428/284512 pid=1 nodes=0
       21 __register_chrdev_region+0x31/0x170 age=282896/284347/284473 pid=1-1705 nodes=0-2
        1 sys_inotify_init+0x76/0x1c0 age=283423 pid=1004 nodes=0
       19 as_get_io_context+0x32/0xd0 age=6/247567/283988 pid=1-11782 nodes=0,2
       10 ida_pre_get+0x4a/0x80 age=277666/283773/284526 pid=0-2177 nodes=0,2
       24 kobject_kset_add_dir+0x37/0xb0 age=282727/283860/284472 pid=1-1723 nodes=0-2
        1 acpi_ds_build_internal_buffer_obj+0xd3/0x11d age=284508 pid=1 nodes=0
       24 con_insert_unipair+0xd7/0x110 age=284438/284438/284438 pid=1 nodes=0,2
        1 uart_open+0x2d2/0x4b0 age=283896 pid=1 nodes=0
       26 dma_pool_create+0x73/0x1a0 age=282762/282833/282916 pid=1705-1723 nodes=0
        1 neigh_table_init_no_netlink+0xd2/0x210 age=284461 pid=1 nodes=0
        2 neigh_parms_alloc+0x2b/0xe0 age=284410/284411/284412 pid=1 nodes=2
        2 neigh_resolve_output+0x1e1/0x280 age=276289/276291/276293 pid=0-2443 nodes=0
        1 netlink_kernel_create+0x90/0x170 age=284472 pid=1 nodes=0
        4 xt_alloc_table_info+0x39/0xf0 age=283958/283958/283959 pid=1 nodes=1
        3 fn_hash_insert+0x473/0x720 age=277653/277661/277666 pid=2177-2185 nodes=0
        1 get_mtrr_state+0x285/0x2a0 age=284526 pid=0 nodes=0
        1 cacheinfo_cpu_callback+0x26d/0x3e0 age=284458 pid=1 nodes=0
       29 kernel_param_sysfs_setup+0x25/0x90 age=284511/284511/284512 pid=1 nodes=0-1,3
        5 process_zones+0x5e/0x170 age=284546/284546/284546 pid=0 nodes=0
        1 drm_core_init+0x48/0x160 age=284421 pid=1 nodes=2

  kmalloc-128: Kernel object freeing
  ------------------------------------------------------------------------
      163 <not-available> age=4295176847 pid=0 nodes=0-3
        1 __vunmap+0x6e/0xf0 age=282907 pid=1723 nodes=0
       28 free_as_io_context+0x12/0x90 age=9243/262197/283474 pid=42-11754 nodes=0
        1 acpi_get_object_info+0x1b7/0x1d4 age=284475 pid=1 nodes=0
        1 do_acpi_find_child+0x45/0x4e age=284475 pid=1 nodes=0

  NUMA nodes           :    0    1    2    3
  ------------------------------------------
  All slabs                 7    2    2    1
  Partial slabs             2    2    0    0

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:46 -07:00
Christoph Lameter 41ecc55b8a SLUB: add CONFIG_SLUB_DEBUG
CONFIG_SLUB_DEBUG can be used to switch off the debugging and sysfs components
of SLUB.  Thus SLUB will be able to replace SLOB.  SLUB can arrange objects in
a denser way than SLOB and the code size should be minimal without debugging
and sysfs support.

Note that CONFIG_SLUB_DEBUG is materially different from CONFIG_SLAB_DEBUG.
CONFIG_SLAB_DEBUG is used to enable slab debugging in SLAB.  SLUB enables
debugging via a boot parameter.  SLUB debug code should always be present.

CONFIG_SLUB_DEBUG can be modified in the embedded config section.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:45 -07:00
Christoph Lameter 02cbc87446 SLUB: move tracking definitions and check_valid_pointer() away from debug code
Move the tracking definitions and the check_valid_pointer() function away from
the debugging related functions.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:45 -07:00
Christoph Lameter 636f0d7de8 SLUB: consolidate trace code
Trace in both slab_alloc and slab_free has a lot of common code.  Use a single
function for both.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:45 -07:00
Christoph Lameter 35e5d7ee27 SLUB: introduce DebugSlab(page)
This replaces the PageError() checking.  DebugSlab is clearer and allows for
future changes to the page bit used.  We also need it to support
CONFIG_SLUB_DEBUG.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:45 -07:00
Christoph Lameter b345970905 SLUB: move resiliency check into SYSFS section
Move the resiliency check into the SYSFS section after validate_slab that is
used by the resiliency check.  This will avoid a forward declaration.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:45 -07:00
Christoph Lameter 7656c72b5a SLUB: add macros for scanning objects in a slab
Scanning of objects happens in a number of functions.  Consolidate that code.
DECLARE_BITMAP instead of coding the declaration for bitmaps.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:45 -07:00
Christoph Lameter 672bba3a4b SLUB: update comments
Update comments throughout SLUB to reflect the new developments.  Fix up
various awkward sentences.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:45 -07:00
Christoph Lameter 26a7bd0302 SLUB: get rid of finish_bootstrap
Its only purpose was to bring some sort of symmetry to sysfs usage when
dealing with bootstrapping per cpu flushing.  Since we do not time out slabs
anymore we have no need to run finish_bootstrap even without sysfs.  Fold it
back into slab_sysfs_init and drop the initcall for the !SYFS case.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:45 -07:00
Christoph Lameter 1f99a283dc SLUB: clean up krealloc
We really do not need all this gaga there.

ksize gives us all the information we need to figure out if the object can
cope with the new size.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:45 -07:00
Christoph Lameter abcd08a6f5 SLUB: use check_valid_pointer in kmem_ptr_validate
We needlessly duplicate code. Also make check_valid_pointer inline.

Signed-off-by: Christoph LAemter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:44 -07:00
Christoph Lameter be7b3fbcef SLUB: after object padding only needed for Redzoning
If no redzoning is selected then we do not need padding before the next
object.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:44 -07:00
Christoph Lameter 65c02d4cfb SLUB: add support for dynamic cacheline size determination
SLUB currently assumes that the cacheline size is static.  However, i386 f.e.
supports dynamic cache line size determination.

Use cache_line_size() instead of L1_CACHE_BYTES in the allocator.

That also explains the purpose of SLAB_HWCACHE_ALIGN.  So we will need to keep
that one around to allow dynamic aligning of objects depending on boot
determination of the cache line size.

[akpm@linux-foundation.org: need to define it before we use it]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:44 -07:00
Michael Opdenacker 59c51591a0 Fix occurrences of "the the "
Signed-off-by: Michael Opdenacker <michael@free-electrons.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2007-05-09 08:57:56 +02:00
Paul Mundt 5f8c9908f2 sh: generic quicklist support.
This moves SH over to the generic quicklists. As per x86_64,
we have special mappings for the PGDs, so these go on their
own list..

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-05-09 01:35:00 +00:00
Roland McGrath 74add80cbd Remove unused variable in get_unmapped_area
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:35:28 -07:00
Jaya Kumar 60b59beafb fbdev: mm: Deferred IO support
This implements deferred IO support in fbdev.  Deferred IO is a way to delay
and repurpose IO.  This implementation is done using mm's page_mkwrite and
page_mkclean hooks in order to detect, delay and then rewrite IO.  This
functionality is used by hecubafb.

[adaplas]
This is useful for graphics hardware with no directly addressable/mappable
framebuffer. Implementing this will allow the "framebuffer" to be accesible
from user space via mmap().

Signed-off-by: Jaya Kumar <jayakumar.lkml@gmail.com>
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:15:26 -07:00
Alexey Dobriyan a5c43dae7a Fix race between cat /proc/slab_allocators and rmmod
Same story as with cat /proc/*/wchan race vs rmmod race, only
/proc/slab_allocators want more info than just symbol name.

Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:15:08 -07:00
Mark Fasheh ef51c97623 Remove do_sync_file_range()
Remove do_sync_file_range() and convert callers to just use
do_sync_mapping_range().

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.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>
2007-05-08 11:15:04 -07:00
Christoph Hellwig 1eeb66a1bb move die notifier handling to common code
This patch moves the die notifier handling to common code.  Previous
various architectures had exactly the same code for it.  Note that the new
code is compiled unconditionally, this should be understood as an appel to
the other architecture maintainer to implement support for it aswell (aka
sprinkling a notify_die or two in the proper place)

arm had a notifiy_die that did something totally different, I renamed it to
arm_notify_die as part of the patch and made it static to the file it's
declared and used at.  avr32 used to pass slightly less information through
this interface and I brought it into line with the other architectures.

[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix vmalloc_sync_all bustage]
[bryan.wu@analog.com: fix vmalloc_sync_all in nommu]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: <linux-arch@vger.kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:15:04 -07:00
Guillaume Chazarain 3e9f45bd18 Factor outstanding I/O error handling
Cleanup: setting an outstanding error on a mapping was open coded too many
times.  Factor it out in mapping_set_error().

Signed-off-by: Guillaume Chazarain <guichaz@yahoo.fr>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:14:57 -07:00
Yasunori Goto 72280ede31 Add white list into modpost.c for memory hotplug code and ia64's machvec section
This patch is add white list into modpost.c for some functions and
ia64's section to fix section mismatchs.

  sparse_index_alloc() and zone_wait_table_init() calls bootmem allocator
  at boot time, and kmalloc/vmalloc at hotplug time. If config
  memory hotplug is on, there are references of bootmem allocater(init text)
  from them (normal text). This is cause of section mismatch.

  Bootmem is called by many functions and it must be
  used only at boot time. I think __init of them should keep for
  section mismatch check. So, I would like to register sparse_index_alloc()
  and zone_wait_table_init() into white list.

  In addition, ia64's .machvec section is function table of some platform
  dependent code. It is mixture of .init.text and normal text. These
  reference of __init functions are valid too.

Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:14:57 -07:00
Yasunori Goto a3142c8e1d Fix section mismatch of memory hotplug related code.
This is to fix many section mismatches of code related to memory hotplug.
I checked compile with memory hotplug on/off on ia64 and x86-64 box.

Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:14:57 -07:00
Dmitriy Monakhov 0ceb331433 mm: move common segment checks to separate helper function
[akpm@linux-foundation.org: cleanup]
Signed-off-by: Monakhov Dmitriy <dmonakhov@openvz.org>
Cc: Christoph Hellwig <hch@lst.de>
Acked-by: Anton Altaparmakov <aia21@cam.ac.uk>
Acked-by: David Chinner <dgc@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:14:57 -07:00
David Woodhouse b46b8f19c9 Increase slab redzone to 64bits
There are two problems with the existing redzone implementation.

Firstly, it's causing misalignment of structures which contain a 64-bit
integer, such as netfilter's 'struct ipt_entry' -- causing netfilter
modules to fail to load because of the misalignment.  (In particular, the
first check in
net/ipv4/netfilter/ip_tables.c::check_entry_size_and_hooks())

On ppc32 and sparc32, amongst others, __alignof__(uint64_t) == 8.

With slab debugging, we use 32-bit redzones. And allocated slab objects
aren't sufficiently aligned to hold a structure containing a uint64_t.

By _just_ setting ARCH_KMALLOC_MINALIGN to __alignof__(u64) we'd disable
redzone checks on those architectures.  By using 64-bit redzones we avoid that
loss of debugging, and also fix the other problem while we're at it.

When investigating this, I noticed that on 64-bit platforms we're using a
32-bit value of RED_ACTIVE/RED_INACTIVE in the 64-bit memory location set
aside for the redzone.  Which means that the four bytes immediately before
or after the allocated object at 0x00,0x00,0x00,0x00 for LE and BE
machines, respectively.  Which is probably not the most useful choice of
poison value.

One way to fix both of those at once is just to switch to 64-bit
redzones in all cases.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:14:57 -07:00
Linus Torvalds 0f9008ef38 Fix up SLUB compile
The newly merged SLUB allocator patches had been generated before the
removal of "struct subsystem", and ended up applying fine, but wouldn't
build based on the current tree as a result.

Fix up that merge error - not that SLUB is likely really ready for
showtime yet, but at least I can fix the trivial stuff.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:31:58 -07:00
Linus Torvalds ef93127e4c Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6
* master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6:
  [SERIAL] sunsu: Fix section mismatch warnings.
  [SPARC64]: pgtable_cache_init() should be __init.
  [SPARC64]: Fix section mismatch warnings in arch/sparc64/kernel/prom.c
  [SPARC64]: Fix section mismatch warnings in arch/sparc64/kernel/pci.c
  [SPARC64]: Fix section mismatch warnings in arch/sparc64/kernel/console.c
  [MM]: sparse_init() should be __init.
  [SPARC64]: Update defconfig.
  [VIDEO]: Add Sun XVR-2500 framebuffer driver.
  [VIDEO]: Add Sun XVR-500 framebuffer driver.
  [SPARC64]: SUN4U PCI-E controller support.
  [SPARC]: Fix comment typo in smp4m_blackbox_current().
  [SCSI] SUNESP: sun_esp.c needs linux/delay.h

Fix up conflict in arch/sparc64/mm/init.c manually due to removal of
pgtable_cache_init() through the -mm patches (even though that patch was
also by David ;)

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:22:48 -07:00
Rafael J. Wysocki b1296cc48b freezer: fix racy usage of try_to_freeze in kswapd
Currently we can miss freeze_process()->signal_wake_up() in kswapd() if it
happens between try_to_freeze() and prepare_to_wait().  To prevent this
from happening we should check freezing(current) before calling schedule().

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:59 -07:00
Rafael J. Wysocki 7be9823491 swsusp: use inline functions for changing page flags
Replace direct invocations of SetPageNosave(), SetPageNosaveFree() etc.  with
calls to inline functions that can be changed in subsequent patches without
modifying the code calling them.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:58 -07:00
Akinobu Mita 4ab688c512 slob: fix page order calculation on not 4KB page
SLOB doesn't calculate correct page order when page size is not 4KB.  This
patch fixes it with using get_order() instead of find_order() which is SLOB
version of get_order().

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:57 -07:00
Christoph Lameter cfce66047f Slab allocators: remove useless __GFP_NO_GROW flag
There is no user remaining and I have never seen any use of that flag.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:57 -07:00
Christoph Lameter 4f10493459 slab allocators: Remove SLAB_CTOR_ATOMIC
SLAB_CTOR atomic is never used which is no surprise since I cannot imagine
that one would want to do something serious in a constructor or destructor.
 In particular given that the slab allocators run with interrupts disabled.
 Actions in constructors and destructors are by their nature very limited
and usually do not go beyond initializing variables and list operations.

(The i386 pgd ctor and dtors do take a spinlock in constructor and
destructor.....  I think that is the furthest we go at this point.)

There is no flag passed to the destructor so removing SLAB_CTOR_ATOMIC also
establishes a certain symmetry.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:57 -07:00
Christoph Lameter 50953fe9e0 slab allocators: Remove SLAB_DEBUG_INITIAL flag
I have never seen a use of SLAB_DEBUG_INITIAL.  It is only supported by
SLAB.

I think its purpose was to have a callback after an object has been freed
to verify that the state is the constructor state again?  The callback is
performed before each freeing of an object.

I would think that it is much easier to check the object state manually
before the free.  That also places the check near the code object
manipulation of the object.

Also the SLAB_DEBUG_INITIAL callback is only performed if the kernel was
compiled with SLAB debugging on.  If there would be code in a constructor
handling SLAB_DEBUG_INITIAL then it would have to be conditional on
SLAB_DEBUG otherwise it would just be dead code.  But there is no such code
in the kernel.  I think SLUB_DEBUG_INITIAL is too problematic to make real
use of, difficult to understand and there are easier ways to accomplish the
same effect (i.e.  add debug code before kfree).

There is a related flag SLAB_CTOR_VERIFY that is frequently checked to be
clear in fs inode caches.  Remove the pointless checks (they would even be
pointless without removeal of SLAB_DEBUG_INITIAL) from the fs constructors.

This is the last slab flag that SLUB did not support.  Remove the check for
unimplemented flags from SLUB.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:57 -07:00
Benjamin Herrenschmidt 4b1d89290b get_unmapped_area doesn't need hugetlbfs hacks anymore
Remove the hugetlbfs specific hacks in toplevel get_unmapped_area() now that
all archs and hugetlbfs itself do the right thing for both cases.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: William Irwin <bill.irwin@oracle.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Andi Kleen <ak@suse.de>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: Matthew Wilcox <willy@debian.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Adam Litke <agl@us.ibm.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:57 -07:00
Benjamin Herrenschmidt 06abdfb47e get_unmapped_area handles MAP_FIXED in generic code
generic arch_get_unmapped_area() now handles MAP_FIXED.  Now that all
implementations have been fixed, change the toplevel get_unmapped_area() to
call into arch or drivers for the MAP_FIXED case.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Andi Kleen <ak@suse.de>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: Matthew Wilcox <willy@debian.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: William Irwin <bill.irwin@oracle.com>
Cc: Adam Litke <agl@us.ibm.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:57 -07:00
David Rientjes 2b45ab3398 oom: fix constraint deadlock
Fixes a deadlock in the OOM killer for allocations that are not
__GFP_HARDWALL.

Before the OOM killer checks for the allocation constraint, it takes
callback_mutex.

constrained_alloc() iterates through each zone in the allocation zonelist
and calls cpuset_zone_allowed_softwall() to determine whether an allocation
for gfp_mask is possible.  If a zone's node is not in the OOM-triggering
task's mems_allowed, it is not exiting, and we did not fail on a
__GFP_HARDWALL allocation, cpuset_zone_allowed_softwall() attempts to take
callback_mutex to check the nearest exclusive ancestor of current's cpuset.
 This results in deadlock.

We now take callback_mutex after iterating through the zonelist since we
don't need it yet.

Cc: Andi Kleen <ak@suse.de>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Cc: Martin J. Bligh <mbligh@mbligh.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:55 -07:00
Yasunori Goto 2b744c01a5 mm: fix handling of panic_on_oom when cpusets are in use
The current panic_on_oom may not work if there is a process using
cpusets/mempolicy, because other nodes' memory may remain.  But some people
want failover by panic ASAP even if they are used.  This patch makes new
setting for its request.

This is tested on my ia64 box which has 3 nodes.

Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Ethan Solomita <solo@google.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:55 -07:00
Akinobu Mita 824ebef122 fault injection: fix failslab with CONFIG_NUMA
Currently failslab injects failures into ____cache_alloc().  But with enabling
CONFIG_NUMA it's not enough to let actual slab allocator functions (kmalloc,
kmem_cache_alloc, ...) return NULL.

This patch moves fault injection hook inside of __cache_alloc() and
__cache_alloc_node().  These are lower call path than ____cache_alloc() and
enable to inject faulures to slab allocators with CONFIG_NUMA.

Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:55 -07:00
Christoph Lameter 5af6083990 slab allocators: Remove obsolete SLAB_MUST_HWCACHE_ALIGN
This patch was recently posted to lkml and acked by Pekka.

The flag SLAB_MUST_HWCACHE_ALIGN is

1. Never checked by SLAB at all.

2. A duplicate of SLAB_HWCACHE_ALIGN for SLUB

3. Fulfills the role of SLAB_HWCACHE_ALIGN for SLOB.

The only remaining use is in sparc64 and ppc64 and their use there
reflects some earlier role that the slab flag once may have had. If
its specified then SLAB_HWCACHE_ALIGN is also specified.

The flag is confusing, inconsistent and has no purpose.

Remove it.

Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:55 -07:00
Nick Piggin 0a27a14a62 mm: madvise avoid exclusive mmap_sem
Avoid down_write of the mmap_sem in madvise when we can help it.

Acked-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:54 -07:00
matze b4169525bc include KERN_* constant in printk() calls in mm/slab.c
Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:54 -07:00
Akinobu Mita bc0055aee4 slob: handle SLAB_PANIC flag
kmem_cache_create() for slob doesn't handle SLAB_PANIC.

Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:54 -07:00
Christoph Lameter 6225e93735 Quicklists for page table pages
On x86_64 this cuts allocation overhead for page table pages down to a
fraction (kernel compile / editing load.  TSC based measurement of times spend
in each function):

no quicklist

pte_alloc               1569048 4.3s(401ns/2.7us/179.7us)
pmd_alloc                780988 2.1s(337ns/2.7us/86.1us)
pud_alloc                780072 2.2s(424ns/2.8us/300.6us)
pgd_alloc                260022 1s(920ns/4us/263.1us)

quicklist:

pte_alloc                452436 573.4ms(8ns/1.3us/121.1us)
pmd_alloc                196204 174.5ms(7ns/889ns/46.1us)
pud_alloc                195688 172.4ms(7ns/881ns/151.3us)
pgd_alloc                 65228 9.8ms(8ns/150ns/6.1us)

pgd allocations are the most complex and there we see the most dramatic
improvement (may be we can cut down the amount of pgds cached somewhat?).  But
even the pte allocations still see a doubling of performance.

1. Proven code from the IA64 arch.

	The method used here has been fine tuned for years and
	is NUMA aware. It is based on the knowledge that accesses
	to page table pages are sparse in nature. Taking a page
	off the freelists instead of allocating a zeroed pages
	allows a reduction of number of cachelines touched
	in addition to getting rid of the slab overhead. So
	performance improves. This is particularly useful if pgds
	contain standard mappings. We can save on the teardown
	and setup of such a page if we have some on the quicklists.
	This includes avoiding lists operations that are otherwise
	necessary on alloc and free to track pgds.

2. Light weight alternative to use slab to manage page size pages

	Slab overhead is significant and even page allocator use
	is pretty heavy weight. The use of a per cpu quicklist
	means that we touch only two cachelines for an allocation.
	There is no need to access the page_struct (unless arch code
	needs to fiddle around with it). So the fast past just
	means bringing in one cacheline at the beginning of the
	page. That same cacheline may then be used to store the
	page table entry. Or a second cacheline may be used
	if the page table entry is not in the first cacheline of
	the page. The current code will zero the page which means
	touching 32 cachelines (assuming 128 byte). We get down
	from 32 to 2 cachelines in the fast path.

3. x86_64 gets lightweight page table page management.

	This will allow x86_64 arch code to faster repopulate pgds
	and other page table entries. The list operations for pgds
	are reduced in the same way as for i386 to the point where
	a pgd is allocated from the page allocator and when it is
	freed back to the page allocator. A pgd can pass through
	the quicklists without having to be reinitialized.

64 Consolidation of code from multiple arches

	So far arches have their own implementation of quicklist
	management. This patch moves that feature into the core allowing
	an easier maintenance and consistent management of quicklists.

Page table pages have the characteristics that they are typically zero or in a
known state when they are freed.  This is usually the exactly same state as
needed after allocation.  So it makes sense to build a list of freed page
table pages and then consume the pages already in use first.  Those pages have
already been initialized correctly (thus no need to zero them) and are likely
already cached in such a way that the MMU can use them most effectively.  Page
table pages are used in a sparse way so zeroing them on allocation is not too
useful.

Such an implementation already exits for ia64.  Howver, that implementation
did not support constructors and destructors as needed by i386 / x86_64.  It
also only supported a single quicklist.  The implementation here has
constructor and destructor support as well as the ability for an arch to
specify how many quicklists are needed.

Quicklists are defined by an arch defining CONFIG_QUICKLIST.  If more than one
quicklist is necessary then we can define NR_QUICK for additional lists.  F.e.
 i386 needs two and thus has

config NR_QUICK
	int
	default 2

If an arch has requested quicklist support then pages can be allocated
from the quicklist (or from the page allocator if the quicklist is
empty) via:

quicklist_alloc(<quicklist-nr>, <gfpflags>, <constructor>)

Page table pages can be freed using:

quicklist_free(<quicklist-nr>, <destructor>, <page>)

Pages must have a definite state after allocation and before
they are freed. If no constructor is specified then pages
will be zeroed on allocation and must be zeroed before they are
freed.

If a constructor is used then the constructor will establish
a definite page state. F.e. the i386 and x86_64 pgd constructors
establish certain mappings.

Constructors and destructors can also be used to track the pages.
i386 and x86_64 use a list of pgds in order to be able to dynamically
update standard mappings.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Andi Kleen <ak@suse.de>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: William Lee Irwin III <wli@holomorphy.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:54 -07:00
Christoph Lameter 70d71228af slub: remove object activities out of checking functions
Make sure that the check function really only check things and do not perform
activities.  Extract the tracing and object seeding out of the two check
functions and place them into slab_alloc and slab_free

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:54 -07:00
Christoph Lameter 2086d26a05 SLUB: Free slabs and sort partial slab lists in kmem_cache_shrink
At kmem_cache_shrink check if we have any empty slabs on the partial
if so then remove them.

Also--as an anti-fragmentation measure--sort the partial slabs so that
the most fully allocated ones come first and the least allocated last.

The next allocations may fill up the nearly full slabs. Having the
least allocated slabs last gives them the maximum chance that their
remaining objects may be freed. Thus we can hopefully minimize the
partial slabs.

I think this is the best one can do in terms antifragmentation
measures. Real defragmentation (meaning moving objects out of slabs with
the least free objects to those that are almost full) can be implemted
by reverse scanning through the list produced here but that would mean
that we need to provide a callback at slab cache creation that allows
the deletion or moving of an object. This will involve slab API
changes, so defer for now.

Cc: Mel Gorman <mel@skynet.ie>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:54 -07:00
Christoph Lameter 88a420e4e2 slub: add ability to list alloc / free callers per slab
This patch enables listing the callers who allocated or freed objects in a
cache.

For example to list the allocators for kmalloc-128 do

cat /sys/slab/kmalloc-128/alloc_calls
      7 sn_io_slot_fixup+0x40/0x700
      7 sn_io_slot_fixup+0x80/0x700
      9 sn_bus_fixup+0xe0/0x380
      6 param_sysfs_setup+0xf0/0x280
    276 percpu_populate+0xf0/0x1a0
     19 __register_chrdev_region+0x30/0x360
      8 expand_files+0x2e0/0x6e0
      1 sys_epoll_create+0x60/0x200
      1 __mounts_open+0x140/0x2c0
     65 kmem_alloc+0x110/0x280
      3 alloc_disk_node+0xe0/0x200
     33 as_get_io_context+0x90/0x280
     74 kobject_kset_add_dir+0x40/0x140
     12 pci_create_bus+0x2a0/0x5c0
      1 acpi_ev_create_gpe_block+0x120/0x9e0
     41 con_insert_unipair+0x100/0x1c0
      1 uart_open+0x1c0/0xba0
      1 dma_pool_create+0xe0/0x340
      2 neigh_table_init_no_netlink+0x260/0x4c0
      6 neigh_parms_alloc+0x30/0x200
      1 netlink_kernel_create+0x130/0x320
      5 fz_hash_alloc+0x50/0xe0
      2 sn_common_hubdev_init+0xd0/0x6e0
     28 kernel_param_sysfs_setup+0x30/0x180
     72 process_zones+0x70/0x2e0

cat /sys/slab/kmalloc-128/free_calls
    558 <not-available>
      3 sn_io_slot_fixup+0x600/0x700
     84 free_fdtable_rcu+0x120/0x260
      2 seq_release+0x40/0x60
      6 kmem_free+0x70/0xc0
     24 free_as_io_context+0x20/0x200
      1 acpi_get_object_info+0x3a0/0x3e0
      1 acpi_add_single_object+0xcf0/0x1e40
      2 con_release_unimap+0x80/0x140
      1 free+0x20/0x40

SLAB_STORE_USER must be enabled for a slab cache by either booting with
"slab_debug" or enabling user tracking specifically for the slab of interest.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:54 -07:00
Christoph Lameter e95eed571e SLUB: Add MIN_PARTIAL
We leave a mininum of partial slabs on nodes when we search for
partial slabs on other node. Define a constant for that value.

Then modify slub to keep MIN_PARTIAL slabs around.

This avoids bad situations where a function frees the last object
in a slab (which results in the page being returned to the page
allocator) only to then allocate one again (which requires getting
a page back from the page allocator if the partial list was empty).
Keeping a couple of slabs on the partial list reduces overhead.

Empty slabs are added to the end of the partial list to insure that
partially allocated slabs are consumed first (defragmentation).

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:54 -07:00
Christoph Lameter 53e15af03b slub: validation of slabs (metadata and guard zones)
This enables validation of slab.  Validation means that all objects are
checked to see if there are redzone violations, if padding has been
overwritten or any pointers have been corrupted.  Also checks the consistency
of slab counters.

Validation enables the detection of metadata corruption without the kernel
having to execute code that actually uses (allocs/frees) and object.  It
allows one to make sure that the slab metainformation and the guard values
around an object have not been compromised.

A single slabcache can be checked by writing a 1 to the "validate" file.

i.e.

echo 1 >/sys/slab/kmalloc-128/validate

or use the slabinfo tool to check all slabs

slabinfo -v

Error messages will show up in the syslog.

Note that validation can only reach slabs that are on a list.  This means that
we are usually restricted to partial slabs and active slabs unless
SLAB_STORE_USER is active which will build a full slab list and allows
validation of slabs that are fully in use.  Booting with "slub_debug" set will
enable SLAB_STORE_USER and then full diagnostic are available.

Note that we attempt to push cpu slabs back to the lists when we start the
check.  If the cpu slab is reactivated before we get to it (another processor
grabs it before we get to it) then it cannot be checked.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:54 -07:00
Christoph Lameter 643b113849 slub: enable tracking of full slabs
If slab tracking is on then build a list of full slabs so that we can verify
the integrity of all slabs and are also able to built list of alloc/free
callers.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:54 -07:00
Christoph Lameter 77c5e2d01a slub: fix object tracking
Object tracking did not work the right way for several call chains. Fix this up
by adding a new parameter to slub_alloc and slub_free that specifies the
caller address explicitly.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:54 -07:00
Christoph Lameter b49af68ff9 Add virt_to_head_page and consolidate code in slab and slub
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:54 -07:00
Christoph Lameter 6d7779538f mm: optimize compound_head() by avoiding a shared page flag
The patch adds PageTail(page) and PageHead(page) to check if a page is the
head or the tail of a compound page.  This is done by masking the two bits
describing the state of a compound page and then comparing them.  So one
comparision and a branch instead of two bit checks and two branches.

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:53 -07:00
Christoph Lameter d85f33855c Make page->private usable in compound pages
If we add a new flag so that we can distinguish between the first page and the
tail pages then we can avoid to use page->private in the first page.
page->private == page for the first page, so there is no real information in
there.

Freeing up page->private makes the use of compound pages more transparent.
They become more usable like real pages.  Right now we have to be careful f.e.
 if we are going beyond PAGE_SIZE allocations in the slab on i386 because we
can then no longer use the private field.  This is one of the issues that
cause us not to support debugging for page size slabs in SLAB.

Having page->private available for SLUB would allow more meta information in
the page struct.  I can probably avoid the 16 bit ints that I have in there
right now.

Also if page->private is available then a compound page may be equipped with
buffer heads.  This may free up the way for filesystems to support larger
blocks than page size.

We add PageTail as an alias of PageReclaim.  Compound pages cannot currently
be reclaimed.  Because of the alias one needs to check PageCompound first.

The RFC for the this approach was discussed at
http://marc.info/?t=117574302800001&r=1&w=2

[nacc@us.ibm.com: fix hugetlbfs]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:53 -07:00
Christoph Lameter 614410d589 SLUB: allocate smallest object size if the user asks for 0 bytes
Makes SLUB behave like SLAB in this area to avoid issues....

Throw a stack dump to alert people.

At some point the behavior should be switched back.  NULL is no memory as
far as I can tell and if the use asked for 0 bytes then he need to get no
memory.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:53 -07:00
Christoph Lameter 47bfdc0d5a SLUB: change default alignments
Structures may contain u64 items on 32 bit platforms that are only able to
address 64 bit items on 64 bit boundaries.  Change the mininum alignment of
slabs to conform to those expectations.

ARCH_KMALLOC_MINALIGN must be changed for good since a variety of structure
are mixed in the general slabs.

ARCH_SLAB_MINALIGN is changed because currently there is no consistent
specification of object alignment.  We may have that in the future when the
KMEM_CACHE and related macros are used to generate slabs.  These pass the
alignment of the structure generated by the compiler to the slab.

With KMEM_CACHE etc we could align structures that do not contain 64
bit values to 32 bit boundaries potentially saving some memory.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:53 -07:00