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authorMichal Hocko <mhocko@suse.com>2016-07-29 01:44:55 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2016-07-29 02:07:41 +0300
commit696453e66630ad45e644c4571307fa3ebec9a835 (patch)
tree1f615e6882b7b4cdacfbac7c972a4b9cc05d661e
parent1af8bb43269563e458ebcf0ece812e9a970864b3 (diff)
downloadlinux-696453e66630ad45e644c4571307fa3ebec9a835.tar.xz
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>
-rw-r--r--mm/oom_kill.c10
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;