Michal Hocko e2fe14564d oom_reaper: close race with exiting task ... Tetsuo has reported: Out of memory: Kill process 443 (oleg's-test) score 855 or sacrifice child Killed process 443 (oleg's-test) total-vm:493248kB, anon-rss:423880kB, file-rss:4kB, shmem-rss:0kB sh invoked oom-killer: gfp_mask=0x24201ca(GFP_HIGHUSER_MOVABLE|__GFP_COLD), order=0, oom_score_adj=0 sh cpuset=/ mems_allowed=0 CPU: 2 PID: 1 Comm: sh Not tainted 4.6.0-rc7+ #51 Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/31/2013 Call Trace: dump_stack+0x85/0xc8 dump_header+0x5b/0x394 oom_reaper: reaped process 443 (oleg's-test), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB In other words: __oom_reap_task exit_mm atomic_inc_not_zero tsk->mm = NULL mmput atomic_dec_and_test # > 0 exit_oom_victim # New victim will be # selected <OOM killer invoked> # no TIF_MEMDIE task so we can select a new one unmap_page_range # to release the memory The race exists even without the oom_reaper because anybody who pins the address space and gets preempted might race with exit_mm but oom_reaper made this race more probable. We can address the oom_reaper part by using oom_lock for __oom_reap_task because this would guarantee that a new oom victim will not be selected if the oom reaper might race with the exit path. This doesn't solve the original issue, though, because somebody else still might be pinning mm_users and so __mmput won't be called to release the memory but that is not really realiably solvable because the task will get away from the oom sight as soon as it is unhashed from the task_list and so we cannot guarantee a new victim won't be selected. [akpm@linux-foundation.org: fix use of unused `mm', Per Stephen] [akpm@linux-foundation.org: coding-style fixes] Fixes: aac4536355 ("mm, oom: introduce oom reaper") Link: http://lkml.kernel.org/r/1464271493-20008-1-git-send-email-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2016-05-27 14:49:37 -07:00
..
kasan	mm: kasan: remove unused 'reserved' field from struct kasan_alloc_meta	2016-05-26 15:35:44 -07:00
backing-dev.c	mm: throttle on IO only when there are too many dirty and writeback pages	2016-05-20 17:58:30 -07:00
balloon_compaction.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2016-03-17 21:38:27 -07:00
bootmem.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
cleancache.c	cleancache: constify cleancache_ops structure	2016-01-27 09:09:57 -05:00
cma_debug.c	mm/cma_debug: correct size input to bitmap function	2015-07-17 16:39:54 -07:00
cma.c	mm/cma.c: suppress warning	2015-11-05 19:34:48 -08:00
cma.h	mm: cma: mark cma_bitmap_maxno() inline in header	2015-08-14 15:56:32 -07:00
compaction.c	mm/compaction.c: fix zoneindex in kcompactd()	2016-05-20 17:58:30 -07:00
debug_page_ref.c	mm/page_ref: add tracepoint to track down page reference manipulation	2016-03-17 15:09:34 -07:00
debug.c	mm: introduce page reference manipulation functions	2016-03-17 15:09:34 -07:00
dmapool.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
early_ioremap.c	mm/early_ioremap: use offset_in_page macro	2015-11-05 19:34:48 -08:00
fadvise.c	mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros	2016-04-04 10:41:08 -07:00
failslab.c	mm: fault-inject take over bootstrap kmem_cache check	2016-03-15 16:55:16 -07:00
filemap.c	Filesystem DAX locking for 4.7	2016-05-26 20:00:28 -07:00
frame_vector.c	mm/gup: Switch all callers of get_user_pages() to not pass tsk/mm	2016-02-16 10:11:12 +01:00
frontswap.c	frontswap: allow multiple backends	2015-06-24 17:49:45 -07:00
gup.c	Merge branch 'mm-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2016-04-14 19:31:34 -07:00
highmem.c	mm/highmem: make nr_free_highpages() handles all highmem zones by itself	2016-05-19 19:12:14 -07:00
huge_memory.c	libnvdimm for 4.7	2016-05-23 11:18:01 -07:00
hugetlb_cgroup.c	mm, hugetlb_cgroup: round limit_in_bytes down to hugepage size	2016-05-20 17:58:30 -07:00
hugetlb.c	libnvdimm for 4.7	2016-05-23 11:18:01 -07:00
hwpoison-inject.c	hwpoison: use page_cgroup_ino for filtering by memcg	2015-09-10 13:29:01 -07:00
init-mm.c
internal.h	mm: make vm_mmap killable	2016-05-23 17:04:14 -07:00
interval_tree.c	mm: replace vma->sharead.linear with vma->shared	2015-02-10 14:30:31 -08:00
Kconfig	mm: make CONFIG_DEFERRED_STRUCT_PAGE_INIT depends on !FLATMEM explicitly	2016-05-26 15:35:44 -07:00
Kconfig.debug	mm/page_ref: add tracepoint to track down page reference manipulation	2016-03-17 15:09:34 -07:00
kmemcheck.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
kmemleak-test.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
kmemleak.c	mm: coalesce split strings	2016-03-17 15:09:34 -07:00
ksm.c	ksm: fix conflict between mmput and scan_get_next_rmap_item	2016-05-12 15:52:50 -07:00
list_lru.c	mm: memcontrol: move kmem accounting code to CONFIG_MEMCG	2016-01-20 17:09:18 -08:00
maccess.c	x86: remove more uaccess_32.h complexity	2016-05-22 17:21:27 -07:00
madvise.c	mm: make mmap_sem for write waits killable for mm syscalls	2016-05-23 17:04:14 -07:00
Makefile	z3fold: the 3-fold allocator for compressed pages	2016-05-20 17:58:30 -07:00
memblock.c	mm/memblock.c: remove unnecessary always-true comparison	2016-05-20 17:58:30 -07:00
memcontrol.c	memcg: fix mem_cgroup_out_of_memory() return value.	2016-05-26 15:35:44 -07:00
memory_hotplug.c	mm: use early_pfn_to_nid in register_page_bootmem_info_node	2016-05-27 14:49:37 -07:00
memory-failure.c	mm/memory-failure.c: replace "MCE" with "Memory failure"	2016-05-20 17:58:30 -07:00
memory.c	Filesystem DAX locking for 4.7	2016-05-26 20:00:28 -07:00
mempolicy.c	mm, page_alloc: avoid looking up the first zone in a zonelist twice	2016-05-19 19:12:14 -07:00
mempool.c	mm: kasan: initial memory quarantine implementation	2016-05-20 17:58:30 -07:00
memtest.c	memtest: remove unused header files	2015-09-08 15:35:28 -07:00
migrate.c	mm, migrate: increment fail count on ENOMEM	2016-05-20 17:58:30 -07:00
mincore.c	mm, fs: remove remaining PAGE_CACHE_* and page_cache_{get,release} usage	2016-04-04 10:41:08 -07:00
mlock.c	mm: make mmap_sem for write waits killable for mm syscalls	2016-05-23 17:04:14 -07:00
mm_init.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
mmap.c	mm: make vm_brk killable	2016-05-23 17:04:14 -07:00
mmu_context.c	mm/mmu_context, sched/core: Fix mmu_context.h assumption	2016-04-28 11:44:19 +02:00
mmu_notifier.c	fix Christoph's email addresses	2016-03-17 15:09:34 -07:00
mmzone.c	mm, page_alloc: inline the fast path of the zonelist iterator	2016-05-19 19:12:14 -07:00
mprotect.c	mm: make mmap_sem for write waits killable for mm syscalls	2016-05-23 17:04:14 -07:00
mremap.c	mm: make mmap_sem for write waits killable for mm syscalls	2016-05-23 17:04:14 -07:00
msync.c	mm/msync: use offset_in_page macro	2015-11-05 19:34:48 -08:00
nobootmem.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
nommu.c	mm: make vm_mmap killable	2016-05-23 17:04:14 -07:00
oom_kill.c	oom_reaper: close race with exiting task	2016-05-27 14:49:37 -07:00
page_alloc.c	mm: check_new_page_bad() directly returns in __PG_HWPOISON case	2016-05-20 17:58:30 -07:00
page_counter.c	mm: page_counter: let page_counter_try_charge() return bool	2015-11-05 19:34:48 -08:00
page_ext.c	mm: use early_pfn_to_nid in page_ext_init	2016-05-27 14:49:37 -07:00
page_idle.c	mm: add page_check_address_transhuge() helper	2016-01-15 17:56:32 -08:00
page_io.c	Merge branch 'work.preadv2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-05-17 15:05:23 -07:00
page_isolation.c	mm/memory_hotplug: add comment to some functions related to memory hotplug	2016-05-19 19:12:14 -07:00
page_owner.c	mm, page_alloc: inline pageblock lookup in page free fast paths	2016-05-19 19:12:14 -07:00
page_poison.c	mm: use existing helper to convert "on"/"off" to boolean	2016-05-20 17:58:30 -07:00
page-writeback.c	MM: increase safety margin provided by PF_LESS_THROTTLE	2016-05-20 17:58:30 -07:00
pagewalk.c	thp: rename split_huge_page_pmd() to split_huge_pmd()	2016-01-15 17:56:32 -08:00
percpu-km.c	mm: percpu: use pr_fmt to prefix output	2016-03-17 15:09:34 -07:00
percpu-vm.c
percpu.c	mm: percpu: use pr_fmt to prefix output	2016-03-17 15:09:34 -07:00
pgtable-generic.c	mm/thp/migration: switch from flush_tlb_range to flush_pmd_tlb_range	2016-03-17 15:09:34 -07:00
process_vm_access.c	mm/gup: Introduce get_user_pages_remote()	2016-02-16 10:04:09 +01:00
quicklist.c	fix Christoph's email addresses	2016-03-17 15:09:34 -07:00
readahead.c	mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros	2016-04-04 10:41:08 -07:00
rmap.c	mm: use __SetPageSwapBacked and dont ClearPageSwapBacked	2016-05-19 19:12:14 -07:00
shmem.c	tmpfs: mem_cgroup charge fault to vm_mm not current mm	2016-05-19 19:12:14 -07:00
slab_common.c	mm: kasan: initial memory quarantine implementation	2016-05-20 17:58:30 -07:00
slab.c	mm, kasan: don't call kasan_krealloc() from ksize().	2016-05-20 17:58:30 -07:00
slab.h	mm: kasan: initial memory quarantine implementation	2016-05-20 17:58:30 -07:00
slob.c	mm: slab: free kmem_cache_node after destroy sysfs file	2016-02-18 16:23:24 -08:00
slub.c	mm, kasan: don't call kasan_krealloc() from ksize().	2016-05-20 17:58:30 -07:00
sparse-vmemmap.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
sparse.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
swap_cgroup.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
swap_state.c	mm: use __SetPageSwapBacked and dont ClearPageSwapBacked	2016-05-19 19:12:14 -07:00
swap.c	mm/swap.c: put activate_page_pvecs and other pagevecs together	2016-05-20 17:58:30 -07:00
swapfile.c	mm: thp: calculate the mapcount correctly for THP pages during WP faults	2016-05-12 15:52:50 -07:00
truncate.c	dax: New fault locking	2016-05-19 15:20:54 -06:00
userfaultfd.c	mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros	2016-04-04 10:41:08 -07:00
util.c	mm: make vm_mmap killable	2016-05-23 17:04:14 -07:00
vmacache.c	mm/vmacache: inline vmacache_valid_mm()	2015-11-05 19:34:48 -08:00
vmalloc.c	Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux	2016-05-23 11:48:48 -07:00
vmpressure.c	mm/vmpressure.c: fix subtree pressure detection	2016-02-03 08:28:43 -08:00
vmscan.c	mm, oom: rework oom detection	2016-05-20 17:58:30 -07:00
vmstat.c	vmstat: get rid of the ugly cpu_stat_off variable	2016-05-20 17:58:30 -07:00
workingset.c	mm: workingset: make shadow node shrinker memcg aware	2016-03-17 15:09:34 -07:00
z3fold.c	z3fold: the 3-fold allocator for compressed pages	2016-05-20 17:58:30 -07:00
zbud.c	mm/zbud.c: use list_last_entry() instead of list_tail_entry()	2016-01-15 11:40:52 -08:00
zpool.c	mm: zsmalloc: constify struct zs_pool name	2015-11-06 17:50:42 -08:00
zsmalloc.c	update "mm/zsmalloc: don't fail if can't create debugfs info"	2016-05-26 15:35:44 -07:00
zswap.c	mm/zswap: use workqueue to destroy pool	2016-05-20 17:58:30 -07:00