On Wed 17-02-16 22:07:31, Tetsuo Handa wrote: > Michal Hocko wrote: > > On Wed 17-02-16 19:30:41, Tetsuo Handa wrote: > > > >From 22bd036766e70f0df38c38f3ecc226e857d20faf Mon Sep 17 00:00:00 2001 > > > From: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> > > > Date: Wed, 17 Feb 2016 16:30:59 +0900 > > > Subject: [PATCH 2/6] mm,oom: don't abort on exiting processes when selecting a victim. > > > > > > Currently, oom_scan_process_thread() returns OOM_SCAN_ABORT when there > > > is a thread which is exiting. But it is possible that that thread is > > > blocked at down_read(&mm->mmap_sem) in exit_mm() called from do_exit() > > > whereas one of threads sharing that memory is doing a GFP_KERNEL > > > allocation between down_write(&mm->mmap_sem) and up_write(&mm->mmap_sem) > > > (e.g. mmap()). Under such situation, the OOM killer does not choose a > > > victim, which results in silent OOM livelock problem. > > > > Again, such a thread/task will have fatal_signal_pending and so have > > access to memory reserves. So the text is slightly misleading imho. > > Sure if the memory reserves are depleted then we will not move on but > > then it is not clear whether the current patch helps either. > > I don't think so. > Please see http://lkml.kernel.org/r/201602151958.HCJ48972.FFOFOLMHSQVJtO@xxxxxxxxxxxxxxxxxxx . I have missed this one. Reading... Hmm, so you are not referring to OOM killed task but naturally exiting thread which is racing with the OOM killer. I guess you have a point there! Could you update the changelog with the above example and repost please? Thanks! -- Michal Hocko SUSE Labs -- 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>