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| author | Michal Hocko <mhocko@suse.com> | 2016-07-29 00:44:55 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-07-29 01:07:41 +0200 |
| commit | 696453e66630ad45e644c4571307fa3ebec9a835 (patch) | |
| tree | 1f615e6882b7b4cdacfbac7c972a4b9cc05d661e /mm/oom_kill.c | |
| parent | mm, oom: fortify task_will_free_mem() (diff) | |
| download | linux-696453e66630ad45e644c4571307fa3ebec9a835.tar.xz linux-696453e66630ad45e644c4571307fa3ebec9a835.zip | |
mm, oom: task_will_free_mem should skip oom_reaped tasks
The 0-day robot has encountered the following:
Out of memory: Kill process 3914 (trinity-c0) score 167 or sacrifice child
Killed process 3914 (trinity-c0) total-vm:55864kB, anon-rss:1512kB, file-rss:1088kB, shmem-rss:25616kB
oom_reaper: reaped process 3914 (trinity-c0), now anon-rss:0kB, file-rss:0kB, shmem-rss:26488kB
oom_reaper: reaped process 3914 (trinity-c0), now anon-rss:0kB, file-rss:0kB, shmem-rss:26900kB
oom_reaper: reaped process 3914 (trinity-c0), now anon-rss:0kB, file-rss:0kB, shmem-rss:26900kB
oom_reaper: reaped process 3914 (trinity-c0), now anon-rss:0kB, file-rss:0kB, shmem-rss:27296kB
oom_reaper: reaped process 3914 (trinity-c0), now anon-rss:0kB, file-rss:0kB, shmem-rss:28148kB
oom_reaper is trying to reap the same task again and again.
This is possible only when the oom killer is bypassed because of
task_will_free_mem because we skip over tasks with MMF_OOM_REAPED
already set during select_bad_process. Teach task_will_free_mem to skip
over MMF_OOM_REAPED tasks as well because they will be unlikely to free
anything more.
Analyzed by Tetsuo Handa.
Link: http://lkml.kernel.org/r/1466426628-15074-9-git-send-email-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Vladimir Davydov <vdavydov@virtuozzo.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>
Diffstat (limited to 'mm/oom_kill.c')
| -rw-r--r-- | mm/oom_kill.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 8ee92fb76968..36d5dd88d990 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -747,6 +747,16 @@ bool task_will_free_mem(struct task_struct *task) return false; mm = p->mm; + + /* + * This task has already been drained by the oom reaper so there are + * only small chances it will free some more + */ + if (test_bit(MMF_OOM_REAPED, &mm->flags)) { + task_unlock(p); + return false; + } + if (atomic_read(&mm->mm_users) <= 1) { task_unlock(p); return true; |