On Wed 17-02-16 19:33:07, Tetsuo Handa wrote: > >From 4924ca3031444bfb831b2d4f004e5a613ad48d68 Mon Sep 17 00:00:00 2001 > From: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> > Date: Wed, 17 Feb 2016 16:35:12 +0900 > Subject: [PATCH 4/6] mm,oom: exclude oom_task_origin processes if they are OOM-unkillable. > > oom_scan_process_thread() returns OOM_SCAN_SELECT when there is a > thread which returns oom_task_origin() == true. But it is possible > that that thread is marked as OOM-unkillable. > > This patch changes oom_scan_process_thread() not to select it > if it is marked as OOM-unkillable. oom_task_origin is only swapoff and ksm_store right now. I seriously doubt anybody sane will run them as OOM disabled (directly or indirectly). But you have a point that returing anything but OOM_SCAN_CONTINUE for OOM_SCORE_ADJ_MIN from oom_scan_process_thread sounds suboptimal. Sure such a check would be racy but do we actually care about a OOM vs. oom_score_adj_write. I am dubious to say the least. So wouldn't it make more sense to check for OOM_SCORE_ADJ_MIN at the very top of oom_scan_process_thread instead? > Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> > --- > 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 b0c327d..ebc6764 100644 > --- a/mm/oom_kill.c > +++ b/mm/oom_kill.c > @@ -308,7 +308,8 @@ enum oom_scan_t oom_scan_process_thread(struct oom_control *oc, > * If task is allocating a lot of memory and has been marked to be > * killed first if it triggers an oom, then select it. > */ > - if (oom_task_origin(task) && !test_tsk_thread_flag(task, TIF_MEMDIE)) > + if (oom_task_origin(task) && !test_tsk_thread_flag(task, TIF_MEMDIE) && > + task->signal->oom_score_adj != OOM_SCORE_ADJ_MIN) > return OOM_SCAN_SELECT; > > return OOM_SCAN_OK; > -- > 1.8.3.1 -- 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>