On Wed 17-02-16 19:32:00, Tetsuo Handa wrote: > >From f5531e726caad7431020c027b6900a8e2c678345 Mon Sep 17 00:00:00 2001 > From: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> > Date: Wed, 17 Feb 2016 16:32:37 +0900 > Subject: [PATCH 3/6] mm,oom: exclude oom_task_origin processes if they are OOM victims. > > Currently, 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 sharing memory with OOM-unkillable processes or the > OOM reaper fails to reclaim enough memory. In that case, we must not > continue selecting such threads forever. > > This patch changes oom_scan_process_thread() not to select a thread > which returns oom_task_origin() = true if TIF_MEMDIE is already set > because SysRq-f case can reach here. Since "mm,oom: exclude TIF_MEMDIE > processes from candidates." made sure that we will choose a !TIF_MEMDIE > thread when only some of threads are marked TIF_MEMDIE, we don't need to > check all threads which returns oom_task_origin() == true. I do not think this is necessary. If you simply do OOM_SCAN_CONTINUE for TIF_MEMDIE && is_sysrq_oom then you should be covered AFAICS. > > Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> > --- > mm/oom_kill.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/oom_kill.c b/mm/oom_kill.c > index a3868fd..b0c327d 100644 > --- a/mm/oom_kill.c > +++ b/mm/oom_kill.c > @@ -308,7 +308,7 @@ 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)) > + if (oom_task_origin(task) && !test_tsk_thread_flag(task, TIF_MEMDIE)) > 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>