WSL2-Linux-Kernel/mm
Linus Torvalds 9b1ea29bc0 Revert "mm, slub: consider rest of partial list if acquire_slab() fails"
This reverts commit 8ff60eb052.

The kernel test robot reports a huge performance regression due to the
commit, and the reason seems fairly straightforward: when there is
contention on the page list (which is what causes acquire_slab() to
fail), we do _not_ want to just loop and try again, because that will
transfer the contention to the 'n->list_lock' spinlock we hold, and
just make things even worse.

This is admittedly likely a problem only on big machines - the kernel
test robot report comes from a 96-thread dual socket Intel Xeon Gold
6252 setup, but the regression there really is quite noticeable:

   -47.9% regression of stress-ng.rawpkt.ops_per_sec

and the commit that was marked as being fixed (7ced37197196: "slub:
Acquire_slab() avoid loop") actually did the loop exit early very
intentionally (the hint being that "avoid loop" part of that commit
message), exactly to avoid this issue.

The correct thing to do may be to pick some kind of reasonable middle
ground: instead of breaking out of the loop on the very first sign of
contention, or trying over and over and over again, the right thing may
be to re-try _once_, and then give up on the second failure (or pick
your favorite value for "once"..).

Reported-by: kernel test robot <oliver.sang@intel.com>
Link: https://lore.kernel.org/lkml/20210301080404.GF12822@xsang-OptiPlex-9020/
Cc: Jann Horn <jannh@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-03-10 10:18:04 -08:00
..
kasan kasan: clarify that only first bug is reported in HW_TAGS 2021-02-26 09:41:03 -08:00
kfence kfence: use error_report_end tracepoint 2021-02-26 09:41:02 -08:00
Kconfig media: videobuf2: Move frame_vector into media subsystem 2021-01-12 14:15:31 +01:00
Kconfig.debug mm, page_poison: remove CONFIG_PAGE_POISONING_ZERO 2020-12-15 12:13:46 -08:00
Makefile mm: add Kernel Electric-Fence infrastructure 2021-02-26 09:41:02 -08:00
backing-dev.c mm/backing-dev.c: use might_alloc() 2021-02-26 09:41:01 -08:00
balloon_compaction.c mm/balloon_compaction: suppress allocation warnings 2019-09-04 07:42:01 -04:00
cleancache.c Driver Core and debugfs changes for 5.3-rc1 2019-07-12 12:24:03 -07:00
cma.c mm: cma: print region name on failure 2021-02-26 09:41:00 -08:00
cma.h mm: cma: use CMA_MAX_NAME to define the length of cma name array 2020-09-01 09:19:43 +02:00
cma_debug.c debugfs: make sure we can remove u32_array files cleanly 2020-07-10 13:54:00 -07:00
compaction.c mm, compaction: make fast_isolate_freepages() stay within zone 2021-02-24 13:38:34 -08:00
debug.c mm/debug: improve memcg debugging 2021-02-24 13:38:27 -08:00
debug_page_ref.c
debug_vm_pgtable.c mm/debug_vm_pgtable/basic: iterate over entire protection_map[] 2021-02-24 13:38:27 -08:00
dmapool.c mm/dmapool: use might_alloc() 2021-02-26 09:41:01 -08:00
early_ioremap.c mm/early_ioremap.c: use __func__ instead of function name 2021-02-26 09:41:02 -08:00
fadvise.c mm, fadvise: improve the expensive remote LRU cache draining after FADV_DONTNEED 2020-10-13 18:38:29 -07:00
failslab.c mm/failslab.c: by default, do not fail allocations with direct reclaim only 2019-07-12 11:05:43 -07:00
filemap.c mm: pass pvec directly to find_get_entries 2021-02-26 09:40:59 -08:00
frontswap.c mm/frontswap: mark various intentional data races 2020-08-14 19:56:56 -07:00
gup.c mm/hugetlb: grab head page refcount once for group of subpages 2021-02-24 13:38:32 -08:00
gup_test.c mm/gup_test.c: mark gup_test_init as __init function 2020-12-15 12:13:38 -08:00
gup_test.h selftests/vm: gup_test: introduce the dump_pages() sub-test 2020-12-15 12:13:38 -08:00
highmem.c mm/highmem: prepare for overriding set_pte_at() 2021-01-24 10:34:52 -08:00
hmm.c mm: do page fault accounting in handle_mm_fault 2020-08-12 10:58:02 -07:00
huge_memory.c mm,thp,shmem: limit shmem THP alloc gfp_mask 2021-02-26 09:40:59 -08:00
hugetlb.c mm/hugetlb: change hugetlb_reserve_pages() to type bool 2021-02-24 13:38:35 -08:00
hugetlb_cgroup.c hugetlb_cgroup: use helper pages_per_huge_page() in hugetlb_cgroup 2021-02-24 13:38:33 -08:00
hwpoison-inject.c mm,hwpoison-inject: don't pin for hwpoison_filter 2020-10-16 11:11:16 -07:00
init-mm.c mm/gup: prevent gup_fast from racing with COW during fork 2020-12-15 12:13:39 -08:00
internal.h mm: add and use find_lock_entries 2021-02-26 09:40:59 -08:00
interval_tree.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 248 2019-06-19 17:09:08 +02:00
ioremap.c mm: move p?d_alloc_track to separate header file 2020-08-07 11:33:26 -07:00
khugepaged.c mm,thp,shmem: make khugepaged obey tmpfs mount flags 2021-02-26 09:40:59 -08:00
kmemleak.c mm/kmemleak: rely on rcu for task stack scanning 2020-10-13 18:38:27 -07:00
ksm.c mm: cleanup kstrto*() usage 2020-12-15 12:13:47 -08:00
list_lru.c mm/list_lru.c: remove kvfree_rcu_local() 2021-02-24 13:38:30 -08:00
maccess.c uaccess: add force_uaccess_{begin,end} helpers 2020-08-12 10:57:59 -07:00
madvise.c idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
mapping_dirty_helpers.c mm/mapping_dirty_helpers: enhance the kernel-doc markups 2020-12-15 12:13:41 -08:00
memblock.c memblock: remove return value of memblock_free_all() 2021-02-22 13:01:23 -08:00
memcontrol.c mm: memcontrol: fix get_active_memcg return value 2021-02-24 13:38:30 -08:00
memfd.c mm: page cache: store only head pages in i_pages 2019-09-24 15:54:08 -07:00
memory-failure.c mm: fix memory_failure() handling of dax-namespace metadata 2021-02-26 09:41:00 -08:00
memory.c MIPS: make userspace mapping young by default 2021-02-26 09:41:05 -08:00
memory_hotplug.c mm/memory_hotplug: prevalidate the address range being added with platform 2021-02-26 09:41:00 -08:00
mempolicy.c mm/mempolicy: use helper range_in_vma() in queue_pages_test_walk() 2021-02-24 13:38:34 -08:00
mempool.c kasan: move _RET_IP_ to inline wrappers 2021-02-24 13:38:31 -08:00
memremap.c mm/memory_hotplug: prevalidate the address range being added with platform 2021-02-26 09:41:00 -08:00
memtest.c
migrate.c mm: memcg: add swapcache stat for memcg v2 2021-02-24 13:38:29 -08:00
mincore.c inode: make init and permission helpers idmapped mount aware 2021-01-24 14:27:16 +01:00
mlock.c mm/mlock: stop counting mlocked pages when none vma is found 2021-02-26 09:41:01 -08:00
mm_init.c mm: fix fall-through warnings for Clang 2020-12-15 12:13:47 -08:00
mmap.c mm/mmap.c: remove unnecessary local variable 2021-02-24 13:38:30 -08:00
mmap_lock.c mm: mmap_lock: add tracepoints around lock acquisition 2020-12-15 12:13:41 -08:00
mmu_gather.c tlb: mmu_gather: Remove start/end arguments from tlb_gather_mmu() 2021-01-29 20:02:29 +01:00
mmu_notifier.c mm: track mmu notifiers in fs_reclaim_acquire/release 2020-12-15 12:13:41 -08:00
mmzone.c mm/lru: replace pgdat lru_lock with lruvec lock 2020-12-15 14:48:04 -08:00
mprotect.c mm/mprotect.c: optimize error detection in do_mprotect_pkey() 2021-02-24 13:38:30 -08:00
mremap.c mm: mremap: unlink anon_vmas when mremap with MREMAP_DONTUNMAP success 2021-02-24 13:38:30 -08:00
msync.c mmap locking API: use coccinelle to convert mmap_sem rwsem call sites 2020-06-09 09:39:14 -07:00
nommu.c mm/nommu: Fix return type of filemap_map_pages() 2021-01-28 14:10:31 +00:00
oom_kill.c mm, oom: fix a comment in dump_task() 2021-02-24 13:38:34 -08:00
page-writeback.c mm: make wait_on_page_writeback() wait for multiple pending writebacks 2021-01-05 11:33:00 -08:00
page_alloc.c mm/page_alloc: count CMA pages per zone and print them in /proc/zoneinfo 2021-02-26 09:41:00 -08:00
page_counter.c mm/page_counter: use page_counter_read in page_counter_set_max 2020-12-15 12:13:40 -08:00
page_ext.c mm: fix some spelling mistakes in comments 2020-12-15 22:46:19 -08:00
page_idle.c mm: page_idle_get_page() does not need lru_lock 2020-12-15 14:48:03 -08:00
page_io.c swap: fix swapfile read/write offset 2021-03-02 17:25:46 -07:00
page_isolation.c mm/page_isolation: do not isolate the max order page 2020-12-15 12:13:45 -08:00
page_owner.c mm/page_owner: use helper function zone_end_pfn() to get end_pfn 2021-02-24 13:38:27 -08:00
page_poison.c kasan, mm: reset tags when accessing metadata 2020-12-22 12:55:08 -08:00
page_reporting.c mm/page_reporting: use list_entry_is_head() in page_reporting_cycle() 2021-02-24 13:38:30 -08:00
page_reporting.h mm: introduce include/linux/pgtable.h 2020-06-09 09:39:13 -07:00
page_vma_mapped.c mm/page_vma_mapped.c: add colon to fix kernel-doc markups error for check_pte 2020-12-15 12:13:41 -08:00
pagewalk.c mmap locking API: convert mmap_sem comments 2020-06-09 09:39:14 -07:00
percpu-internal.h mm: memcg/percpu: account percpu memory to memory cgroups 2020-08-12 10:57:55 -07:00
percpu-km.c mm: memcg/percpu: account percpu memory to memory cgroups 2020-08-12 10:57:55 -07:00
percpu-stats.c mm: memcg/percpu: account percpu memory to memory cgroups 2020-08-12 10:57:55 -07:00
percpu-vm.c mm: memcg/percpu: account percpu memory to memory cgroups 2020-08-12 10:57:55 -07:00
percpu.c percpu: fix clang modpost section mismatch 2021-02-14 18:15:15 +00:00
pgalloc-track.h mm: move p?d_alloc_track to separate header file 2020-08-07 11:33:26 -07:00
pgtable-generic.c mm/pgtable-generic.c: optimize the VM_BUG_ON condition in pmdp_huge_clear_flush() 2021-02-24 13:38:30 -08:00
process_vm_access.c mm/process_vm_access.c: include compat.h 2021-01-12 18:12:54 -08:00
ptdump.c kasan, arm64: expand CONFIG_KASAN checks 2020-12-22 12:55:08 -08:00
readahead.c mm: use limited read-ahead to satisfy read 2020-10-17 13:49:08 -06:00
rmap.c mm/rmap: correct obsolete comment of page_get_anon_vma() 2021-02-26 09:41:01 -08:00
rodata_test.c mm/rodata_test.c: fix missing function declaration 2020-08-21 09:52:53 -07:00
shmem.c mm,shmem,thp: limit shmem THP allocations to requested zones 2021-02-26 09:40:59 -08:00
shuffle.c mm: rename page_order() to buddy_order() 2020-10-16 11:11:19 -07:00
shuffle.h mm/shuffle: remove dynamic reconfiguration 2020-08-07 11:33:29 -07:00
slab.c mm, kfence: insert KFENCE hooks for SLAB 2021-02-26 09:41:02 -08:00
slab.h mm: memcg/slab: pre-allocate obj_cgroups for slab caches with SLAB_ACCOUNT 2021-02-24 13:38:29 -08:00
slab_common.c kasan, mm: optimize krealloc poisoning 2021-02-26 09:41:03 -08:00
slob.c mm, tracing: record slab name for kmem_cache_free() 2021-02-24 13:38:26 -08:00
slub.c Revert "mm, slub: consider rest of partial list if acquire_slab() fails" 2021-03-10 10:18:04 -08:00
sparse-vmemmap.c mm/sparse: only sub-section aligned range would be populated 2020-08-07 11:33:27 -07:00
sparse.c mm/memory_hotplug: guard more declarations by CONFIG_MEMORY_HOTPLUG 2020-10-16 11:11:18 -07:00
swap.c mm: remove pagevec_lookup_entries 2021-02-26 09:40:59 -08:00
swap_cgroup.c mm: memcontrol: make swap tracking an integral part of memory control 2020-06-03 20:09:48 -07:00
swap_slots.c mm/swap_slots.c: remove redundant NULL check 2021-02-24 13:38:28 -08:00
swap_state.c mm: add FGP_ENTRY 2021-02-26 09:40:59 -08:00
swapfile.c swap: fix swapfile read/write offset 2021-03-02 17:25:46 -07:00
truncate.c mm: remove pagevec_lookup_entries 2021-02-26 09:40:59 -08:00
usercopy.c mm/usercopy.c: delete duplicated word 2020-08-12 10:57:58 -07:00
userfaultfd.c mm/vmscan: protect the workingset on anonymous LRU 2020-08-12 10:57:55 -07:00
util.c mm: Make mem_dump_obj() handle vmalloc() memory 2021-01-22 15:24:04 -08:00
vmacache.c kernel: better document the use_mm/unuse_mm API contract 2020-06-10 19:14:18 -07:00
vmalloc.c Merge branch 'for-mingo-rcu' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu 2021-02-12 12:56:55 +01:00
vmpressure.c mm: vmpressure: use mem_cgroup_is_root API 2020-04-02 09:35:31 -07:00
vmscan.c mm/vmscan: restore zone_reclaim_mode ABI 2021-02-24 13:38:34 -08:00
vmstat.c mm/vmstat.c: erase latency in vmstat_shepherd 2021-02-26 09:41:00 -08:00
workingset.c mm: workingset: clarify eviction order and distance calculation 2021-02-24 13:38:34 -08:00
z3fold.c mm: set the sleep_mapped to true for zbud and z3fold 2021-02-26 09:41:01 -08:00
zbud.c mm: set the sleep_mapped to true for zbud and z3fold 2021-02-26 09:41:01 -08:00
zpool.c mm/zswap: add the flag can_sleep_mapped 2021-02-26 09:41:01 -08:00
zsmalloc.c mm/zsmalloc.c: use page_private() to access page->private 2021-02-26 09:41:01 -08:00
zswap.c mm/zswap: add the flag can_sleep_mapped 2021-02-26 09:41:01 -08:00