kernel_optimize_test/mm
Rik van Riel 388f12dabb mm,vmscan: fix divide by zero in get_scan_count
commit 32d4f4b782bb8f0ceb78c6b5dc46eb577ae25bf7 upstream.

Commit f56ce412a59d ("mm: memcontrol: fix occasional OOMs due to
proportional memory.low reclaim") introduced a divide by zero corner
case when oomd is being used in combination with cgroup memory.low
protection.

When oomd decides to kill a cgroup, it will force the cgroup memory to
be reclaimed after killing the tasks, by writing to the memory.max file
for that cgroup, forcing the remaining page cache and reclaimable slab
to be reclaimed down to zero.

Previously, on cgroups with some memory.low protection that would result
in the memory being reclaimed down to the memory.low limit, or likely
not at all, having the page cache reclaimed asynchronously later.

With f56ce412a59d the oomd write to memory.max tries to reclaim all the
way down to zero, which may race with another reclaimer, to the point of
ending up with the divide by zero below.

This patch implements the obvious fix.

Link: https://lkml.kernel.org/r/20210826220149.058089c6@imladris.surriel.com
Fixes: f56ce412a59d ("mm: memcontrol: fix occasional OOMs due to proportional memory.low reclaim")
Signed-off-by: Rik van Riel <riel@surriel.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Chris Down <chris@chrisdown.name>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-18 13:40:36 +02:00
..
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
cleancache.c
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: ensure THP availability via has_transparent_hugepage() 2021-07-14 16:56:13 +02:00
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
fadvise.c mm, fadvise: improve the expensive remote LRU cache draining after FADV_DONTNEED 2020-10-13 18:38:29 -07:00
failslab.c
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: fix try_grab_compound_head() race with split_huge_page() 2021-07-14 16:55:42 +02:00
highmem.c mm/highmem.c: clean up endif comments 2020-10-16 11:11:18 -07:00
hmm.c mm/hmm: bypass devmap pte when all pfn requested flags are fulfilled 2021-09-18 13:40:36 +02:00
huge_memory.c mm/userfaultfd: fix uffd-wp special cases for fork() 2021-07-25 14:36:18 +02:00
hugetlb_cgroup.c hugetlb_cgroup: fix imbalanced css_get and css_put pair for shared mappings 2021-03-30 14:31:54 +02:00
hugetlb.c hugetlb: fix hugetlb cgroup refcounting during vma split 2021-09-18 13:40:36 +02:00
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/thp: fix vma_address() if virtual address below file offset 2021-06-30 08:47:27 -04:00
interval_tree.c
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/huge_memory.c: add missing read-only THP checking in transparent_hugepage_enabled() 2021-07-14 16:56:50 +02:00
kmemleak.c mm/kmemleak: rely on rcu for task stack scanning 2020-10-13 18:38:27 -07:00
ksm.c ksm: fix potential missing rmap_item for stable_node 2021-05-19 10:13:07 +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/madvise: replace ptrace attach requirement for process_madvise 2021-03-17 17:06:37 +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
memblock.c memblock: make for_each_mem_range() traverse MEMBLOCK_HOTPLUG regions 2021-07-28 14:35:46 +02:00
memcontrol.c mm: memcg/slab: properly set up gfp flags for objcg pointer array 2021-07-14 16:56:14 +02:00
memfd.c
memory_hotplug.c arm64: mte: Map hotplugged memory as Normal Tagged 2021-03-17 17:06:28 +01:00
memory-failure.c mm,hwpoison: return -EBUSY when migration fails 2021-07-19 09:44:56 +02:00
memory.c mm/userfaultfd: fix uffd-wp special cases for fork() 2021-07-25 14:36:18 +02:00
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, thp: use head page in __migration_entry_wait() 2021-06-30 08:47:26 -04:00
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_notifiers: ensure range_end() is paired with range_start() 2021-03-30 14:32:06 +02:00
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
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: speed up the iteration of max_order 2021-09-12 08:58:26 +02:00
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
page_idle.c
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
page_vma_mapped.c mm/thp: another PVMW_SYNC fix in page_vma_mapped_walk() 2021-06-30 08:47:29 -04:00
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 percpu: make pcpu_nr_empty_pop_pages per chunk type 2021-04-14 08:42:03 +02:00
percpu-km.c mm: memcg/percpu: account percpu memory to memory cgroups 2020-08-12 10:57:55 -07:00
percpu-stats.c percpu: make pcpu_nr_empty_pop_pages per chunk type 2021-04-14 08:42:03 +02:00
percpu-vm.c mm: memcg/percpu: account percpu memory to memory cgroups 2020-08-12 10:57:55 -07:00
percpu.c percpu: make pcpu_nr_empty_pop_pages per chunk type 2021-04-14 08:42:03 +02:00
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/thp: fix __split_huge_pmd_locked() on shmem migration entry 2021-06-30 08:47:26 -04:00
process_vm_access.c mm/process_vm_access.c: include compat.h 2021-01-19 18:27:21 +01:00
ptdump.c mm: ptdump: fix build failure 2021-04-21 13:00:57 +02:00
readahead.c mm: use limited read-ahead to satisfy read 2020-10-17 13:49:08 -06:00
rmap.c mm/thp: fix page_address_in_vma() on file THP tails 2021-06-30 08:47:27 -04:00
rodata_test.c mm/rodata_test.c: fix missing function declaration 2020-08-21 09:52:53 -07:00
shmem.c Revert "mm/shmem: fix shmem_swapin() race with swapoff" 2021-07-25 14:36:20 +02:00
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/slub: fix redzoning for small allocations 2021-06-23 14:42:54 +02:00
slab.c mm/sl?b.c: remove ctor argument from kmem_cache_flags 2021-05-14 09:50:45 +02:00
slab.h mm: memcg/slab: properly set up gfp flags for objcg pointer array 2021-07-14 16:56:14 +02:00
slob.c mm: memcg: convert vmstat slab counters to bytes 2020-08-07 11:33:24 -07:00
slub.c mm/slub.c: include swab.h 2021-06-23 14:42:54 +02:00
sparse-vmemmap.c mm/sparse: only sub-section aligned range would be populated 2020-08-07 11:33:27 -07:00
sparse.c mm/sparse: add the missing sparse_buffer_fini() in error branch 2021-05-14 09:50:45 +02:00
swap_cgroup.c
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 mm/swap: fix pte_same_as_swp() not removing uffd-wp bit when compare 2021-06-23 14:42:53 +02:00
truncate.c mm/thp: unmap_mapping_page() to fix THP truncate_cleanup_page() 2021-06-30 08:47:27 -04:00
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
vmscan.c mm,vmscan: fix divide by zero in get_scan_count 2021-09-18 13:40:36 +02:00
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 mm/z3fold: use release_z3fold_page_locked() to release locked z3fold page 2021-07-14 16:56:51 +02:00
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