linux_dsm_epyc7002/mm
Linus Torvalds e175916087 Revert "mm, slub: consider rest of partial list if acquire_slab() fails"
commit 9b1ea29bc0d7b94d420f96a0f4121403efc3dd85 upstream.

This reverts commit 8ff60eb052eeba95cfb3efe16b08c9199f8121cf.

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 (7ced371971: "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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 17:06:13 +01:00
..
kasan kasan: fix incorrect arguments passing in kasan_add_zero_shadow 2021-01-27 11:55:23 +01:00
backing-dev.c bdi: replace BDI_CAP_NO_{WRITEBACK,ACCT_DIRTY} with a single flag 2020-09-24 13:43:39 -06:00
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_debug.c debugfs: make sure we can remove u32_array files cleanly 2020-07-10 13:54:00 -07:00
cma.c cma: don't quit at first error when activating reserved areas 2020-08-12 10:57:57 -07:00
cma.h mm: cma: use CMA_MAX_NAME to define the length of cma name array 2020-09-01 09:19:43 +02:00
compaction.c mm, compaction: make fast_isolate_freepages() stay within zone 2021-03-04 11:38:38 +01:00
debug_page_ref.c
debug_vm_pgtable.c mm/debug_vm_pgtable: avoid doing memory allocation with pgtable_t mapped. 2020-10-16 11:11:14 -07:00
debug.c mm, dump_page: rename head_mapcount() --> head_compound_mapcount() 2020-10-13 18:38:29 -07:00
dmapool.c mm/dmapool.c: replace hard coded function name with __func__ 2020-10-13 18:38:32 -07:00
early_ioremap.c mm/early_ioremap.c: use %pa to print resource_size_t variables 2020-01-31 10:30:38 -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/filemap: add missing mem_cgroup_uncharge() to __add_to_page_cache_locked() 2021-02-10 09:29:21 +01:00
frame_vector.c mmap locking API: convert mmap_sem comments 2020-06-09 09:39:14 -07:00
frontswap.c mm/frontswap: mark various intentional data races 2020-08-14 19:56:56 -07:00
gup_benchmark.c mm/gup_benchmark: take the mmap lock around GUP 2020-10-18 09:27:09 -07:00
gup.c mm/gup: combine put_compound_head() and unpin_user_page() 2020-12-30 11:53:54 +01:00
highmem.c mm/highmem.c: clean up endif comments 2020-10-16 11:11:18 -07:00
hmm.c mm: do page fault accounting in handle_mm_fault 2020-08-12 10:58:02 -07:00
huge_memory.c mm: thp: fix MADV_REMOVE deadlock on shmem THP 2021-02-10 09:29:21 +01:00
hugetlb_cgroup.c hugetlb_cgroup: fix offline of hugetlb cgroup with reservations 2020-12-06 10:19:07 -08:00
hugetlb.c mm/hugetlb.c: fix unnecessary address expansion of pmd sharing 2021-03-07 12:34:06 +01:00
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 2020-12-30 11:53:54 +01:00
internal.h mm: rename page_order() to buddy_order() 2020-10-16 11:11:19 -07:00
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
Kconfig mm/zsmalloc.c: drop ZSMALLOC_PGTABLE_MAPPING 2020-12-06 10:19:07 -08:00
Kconfig.debug treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
khugepaged.c mm,thp,shmem: make khugepaged obey tmpfs mount flags 2021-03-04 11:38:20 +01:00
kmemleak.c mm/kmemleak: rely on rcu for task stack scanning 2020-10-13 18:38:27 -07:00
ksm.c docs: get rid of :c:type explicit declarations for structs 2020-10-15 07:49:40 +02:00
list_lru.c mm: list_lru: set shrinker map bit when child nr_items is not zero 2020-12-06 10:19:07 -08:00
maccess.c uaccess: add force_uaccess_{begin,end} helpers 2020-08-12 10:57:59 -07:00
madvise.c mm,memory_failure: always pin the page in madvise_inject_error 2020-12-30 11:53:55 +01:00
Makefile mm,kmemleak-test.c: move kmemleak-test.c to samples dir 2020-10-13 18:38:27 -07:00
mapping_dirty_helpers.c mm/mapping_dirty_helpers: update huge page-table entry callbacks 2020-04-02 09:35:29 -07:00
memblock.c memblock: do not start bottom-up allocations with kernel_end 2021-02-10 09:29:15 +01:00
memcontrol.c mm: memcontrol: fix get_active_memcg return value 2021-03-04 11:38:38 +01:00
memfd.c mm: page cache: store only head pages in i_pages 2019-09-24 15:54:08 -07:00
memory_hotplug.c mm: memmap defer init doesn't work as expected 2021-01-06 14:56:50 +01:00
memory-failure.c mm: fix memory_failure() handling of dax-namespace metadata 2021-03-04 11:38:21 +01:00
memory.c hugetlb: fix copy_huge_page_from_user contig page struct assumption 2021-03-04 11:38:38 +01:00
mempolicy.c mm: mempolicy: fix potential pte_unmap_unlock pte error 2020-11-02 12:14:19 -08:00
mempool.c mm/mempool: add 'else' to split mutually exclusive case 2020-10-13 18:38:34 -07:00
memremap.c mm: fix memory_failure() handling of dax-namespace metadata 2021-03-04 11:38:21 +01:00
memtest.c
migrate.c mm: fix numa stats for thp migration 2021-01-27 11:55:14 +01:00
mincore.c mm: factor find_get_incore_page out of mincore_page 2020-10-13 18:38:29 -07:00
mlock.c mlock: fix unevictable_pgs event counts on THP 2020-09-19 13:13:38 -07:00
mm_init.c mm: adjust vm_committed_as_batch according to vm overcommit policy 2020-08-07 11:33:26 -07:00
mmap.c mm/mmap.c: fix mmap return value when vma is merged after call_mmap() 2020-12-06 10:19:07 -08:00
mmu_gather.c mmap locking API: convert mmap_sem comments 2020-06-09 09:39:14 -07:00
mmu_notifier.c mm/mmu_notifier: fix mmget() assert in __mmu_interval_notifier_insert 2020-10-16 11:11:17 -07:00
mmzone.c
mprotect.c mm: Introduce arch_validate_flags() 2020-09-04 12:46:07 +01:00
mremap.c mm/mremap: start addresses are properly aligned 2020-08-07 11:33:27 -07:00
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: remove alloc_vm_area 2020-10-18 09:27:10 -07:00
oom_kill.c mm, oom_adj: don't loop through tasks in __set_oom_adj when not necessary 2020-10-13 18:38:35 -07:00
page_alloc.c mm/page_alloc: add a missing mm_page_alloc_zone_locked() tracepoint 2021-01-30 13:55:19 +01:00
page_counter.c mm/page_counter: correct the obsolete func name in the comment of page_counter_try_charge() 2020-10-13 18:38:30 -07:00
page_ext.c mm/page_ext.c: drop pfn_present() check when onlining 2020-04-07 10:43:40 -07:00
page_idle.c mm/page_idle.c: skip offline pages 2020-06-08 11:05:55 -07:00
page_io.c swap: fix swapfile read/write offset 2021-03-07 12:34:15 +01:00
page_isolation.c mm: rename page_order() to buddy_order() 2020-10-16 11:11:19 -07:00
page_owner.c mm: rename page_order() to buddy_order() 2020-10-16 11:11:19 -07:00
page_poison.c mm/page_poison.c: replace bool variable with static key 2020-10-16 11:11:17 -07:00
page_reporting.c mm: rename page_order() to buddy_order() 2020-10-16 11:11:19 -07:00
page_reporting.h mm: introduce include/linux/pgtable.h 2020-06-09 09:39:13 -07:00
page_vma_mapped.c mm: replace hpage_nr_pages with thp_nr_pages 2020-08-14 19:56:56 -07:00
page-writeback.c mm: make wait_on_page_writeback() wait for multiple pending writebacks 2021-01-12 20:18:22 +01:00
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: convert flexible array initializers to use struct_size() 2020-10-30 23:02:28 +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: introduce include/linux/pgtable.h 2020-06-09 09:39:13 -07:00
process_vm_access.c mm/process_vm_access.c: include compat.h 2021-01-19 18:27:21 +01:00
ptdump.c mmap locking API: use coccinelle to convert mmap_sem rwsem call sites 2020-06-09 09:39:14 -07:00
readahead.c mm: use limited read-ahead to satisfy read 2020-10-17 13:49:08 -06:00
rmap.c mm/rmap: always do TTU_IGNORE_ACCESS 2020-12-30 11:53:55 +01:00
rodata_test.c mm/rodata_test.c: fix missing function declaration 2020-08-21 09:52:53 -07:00
shmem.c fs: add a filesystem flag for THPs 2020-10-16 11:11:15 -07:00
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_common.c mm: memcontrol: fix slub memory accounting 2021-03-04 11:38:19 +01:00
slab.c mm: fix some comments formatting 2020-10-16 11:11:19 -07:00
slab.h mm: memcg/slab: fix obj_cgroup_charge() return value handling 2020-12-06 10:19:07 -08:00
slob.c mm: memcg: convert vmstat slab counters to bytes 2020-08-07 11:33:24 -07:00
slub.c Revert "mm, slub: consider rest of partial list if acquire_slab() fails" 2021-03-17 17:06:13 +01:00
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_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 always zero and unused return value of enable_swap_slots_cache() 2020-10-13 18:38:30 -07:00
swap_state.c mm: fix some broken comments 2020-10-16 11:11:19 -07:00
swap.c mm: move call to compound_head() in release_pages() 2020-10-13 18:38:33 -07:00
swapfile.c swap: fix swapfile read/write offset 2021-03-07 12:34:15 +01:00
truncate.c mm/truncate.c: make __invalidate_mapping_pages() static 2020-11-02 12:14:19 -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/util.c: update the kerneldoc for kstrdup_const() 2020-10-16 11:11:17 -07:00
vmacache.c kernel: better document the use_mm/unuse_mm API contract 2020-06-10 19:14:18 -07:00
vmalloc.c mm/vmalloc.c: fix potential memory leak 2021-01-19 18:27:21 +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 2021-03-04 11:38:38 +01:00
vmstat.c mm/vmstat.c: use helper macro abs() 2020-10-16 11:11:17 -07:00
workingset.c XArray updates for 5.9 2020-10-20 14:39:37 -07:00
z3fold.c z3fold: stricter locking and more careful reclaim 2020-12-30 11:54:10 +01:00
zbud.c mm/zbud: remove redundant initialization 2020-10-13 18:38:34 -07:00
zpool.c mm/zpool.c: delete duplicated word and fix grammar 2020-08-12 10:57:58 -07:00
zsmalloc.c zsmalloc: account the number of compacted pages correctly 2021-03-07 12:34:15 +01:00
zswap.c mm/zswap: allow setting default status, compressor and allocator in Kconfig 2020-04-07 10:43:41 -07:00