I have missed one important point. exit_oom_victim has to do test_and_clear to make sure we do not race now with this patch. So we need to fold the following into the patch --- >From 296166b049ceb8b3199019a24aebab032998ebb0 Mon Sep 17 00:00:00 2001 From: Michal Hocko <mho...@suse.com> Date: Thu, 28 Jan 2016 23:27:26 +0100 Subject: [PATCH] oom-clear-tif_memdie-after-oom_reaper-managed-to-unmap-the-address-space-fix
Now that exit_oom_victim might be called on a remote task from __oom_reap_task we have to check and clear the flag atomically otherwise we might race and underflow oom_victims or wake up waiters too early. Signed-off-by: Michal Hocko <mho...@suse.com> --- mm/oom_kill.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 7209e517adf2..8f5488345c42 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -603,7 +603,8 @@ void mark_oom_victim(struct task_struct *tsk) */ void exit_oom_victim(struct task_struct *tsk) { - clear_tsk_thread_flag(tsk, TIF_MEMDIE); + if (!test_and_clear_tsk_thread_flag(tsk, TIF_MEMDIE)) + return; if (!atomic_dec_return(&oom_victims)) wake_up_all(&oom_victims_wait); -- 2.7.0.rc3 -- Michal Hocko SUSE Labs