From: Michal Hocko <mhocko@xxxxxxxx> 0-day robot has encountered the following: [ 82.694232] Out of memory: Kill process 3914 (trinity-c0) score 167 or sacrifice child [ 82.695110] Killed process 3914 (trinity-c0) total-vm:55864kB, anon-rss:1512kB, file-rss:1088kB, shmem-rss:25616kB [ 82.706724] oom_reaper: reaped process 3914 (trinity-c0), now anon-rss:0kB, file-rss:0kB, shmem-rss:26488kB [ 82.715540] oom_reaper: reaped process 3914 (trinity-c0), now anon-rss:0kB, file-rss:0kB, shmem-rss:26900kB [ 82.717662] oom_reaper: reaped process 3914 (trinity-c0), now anon-rss:0kB, file-rss:0kB, shmem-rss:26900kB [ 82.725804] oom_reaper: reaped process 3914 (trinity-c0), now anon-rss:0kB, file-rss:0kB, shmem-rss:27296kB [ 82.739091] 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 <penguin-kernel@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Michal Hocko <mhocko@xxxxxxxx> --- mm/oom_kill.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 64dbffa708fd..70992f0f1b78 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -742,6 +742,16 @@ 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; -- 2.8.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>