Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1227361
| From | Oleg Nesterov <oleg@redhat.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH] mm/oom_kill.c: don't kill TASK_UNINTERRUPTIBLE tasks |
| Date | 2015-09-17 21:30 +0200 |
| Message-ID | <q9N2y-4KB-15@gated-at.bofh.it> (permalink) |
| References | <q9LN8-2Wt-13@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
Add cc's. On 09/17, Kyle Walker wrote: > > Currently, the oom killer will attempt to kill a process that is in > TASK_UNINTERRUPTIBLE state. For tasks in this state for an exceptional > period of time, such as processes writing to a frozen filesystem during > a lengthy backup operation, this can result in a deadlock condition as > related processes memory access will stall within the page fault > handler. > > Within oom_unkillable_task(), check for processes in > TASK_UNINTERRUPTIBLE (TASK_KILLABLE omitted). The oom killer will > move on to another task. > > Signed-off-by: Kyle Walker <kwalker@redhat.com> > --- > mm/oom_kill.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/mm/oom_kill.c b/mm/oom_kill.c > index 1ecc0bc..66f03f8 100644 > --- a/mm/oom_kill.c > +++ b/mm/oom_kill.c > @@ -131,6 +131,10 @@ static bool oom_unkillable_task(struct task_struct *p, > if (memcg && !task_in_mem_cgroup(p, memcg)) > return true; > > + /* Uninterruptible tasks should not be killed unless in TASK_WAKEKILL */ > + if (p->state == TASK_UNINTERRUPTIBLE) > + return true; > + So we can skip a memory hog which, say, does mutex_lock(). And this can't help if this task is multithreaded, unless all its sub-threads are in "D" state too oom killer will pick another thread with the same ->mm. Plus other problems. But yes, such a deadlock is possible. I would really like to see the comments from maintainers. In particular, I seem to recall that someone suggested to try to kill another !TIF_MEMDIE process after timeout, perhaps this is what we should actually do... Oleg. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[PATCH] mm/oom_kill.c: don't kill TASK_UNINTERRUPTIBLE tasks Kyle Walker <kwalker@redhat.com> - 2015-09-17 20:10 +0200
Re: [PATCH] mm/oom_kill.c: don't kill TASK_UNINTERRUPTIBLE tasks Oleg Nesterov <oleg@redhat.com> - 2015-09-17 21:30 +0200
Re: [PATCH] mm/oom_kill.c: don't kill TASK_UNINTERRUPTIBLE tasks Christoph Lameter <cl@linux.com> - 2015-09-18 17:50 +0200
Re: [PATCH] mm/oom_kill.c: don't kill TASK_UNINTERRUPTIBLE tasks Oleg Nesterov <oleg@redhat.com> - 2015-09-18 18:30 +0200
Re: [PATCH] mm/oom_kill.c: don't kill TASK_UNINTERRUPTIBLE tasks Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2015-09-18 18:50 +0200
Re: [PATCH] mm/oom_kill.c: don't kill TASK_UNINTERRUPTIBLE tasks Oleg Nesterov <oleg@redhat.com> - 2015-09-18 19:00 +0200
Re: [PATCH] mm/oom_kill.c: don't kill TASK_UNINTERRUPTIBLE tasks Christoph Lameter <cl@linux.com> - 2015-09-18 19:10 +0200
Re: [PATCH] mm/oom_kill.c: don't kill TASK_UNINTERRUPTIBLE tasks Oleg Nesterov <oleg@redhat.com> - 2015-09-18 21:20 +0200
Re: [PATCH] mm/oom_kill.c: don't kill TASK_UNINTERRUPTIBLE tasks Christoph Lameter <cl@linux.com> - 2015-09-18 21:20 +0200
Re: [PATCH] mm/oom_kill.c: don't kill TASK_UNINTERRUPTIBLE tasks Christoph Lameter <cl@linux.com> - 2015-09-19 00:10 +0200
Re: [PATCH] mm/oom_kill.c: don't kill TASK_UNINTERRUPTIBLE tasks Michal Hocko <mhocko@kernel.org> - 2015-09-19 10:40 +0200
Re: [PATCH] mm/oom_kill.c: don't kill TASK_UNINTERRUPTIBLE tasks Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2015-09-19 16:40 +0200
Re: [PATCH] mm/oom_kill.c: don't kill TASK_UNINTERRUPTIBLE tasks Michal Hocko <mhocko@kernel.org> - 2015-09-19 18:00 +0200
Re: [PATCH] mm/oom_kill.c: don't kill TASK_UNINTERRUPTIBLE tasks David Rientjes <rientjes@google.com> - 2015-09-22 01:40 +0200
Re: [PATCH] mm/oom_kill.c: don't kill TASK_UNINTERRUPTIBLE tasks Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2015-09-22 07:40 +0200
Re: [PATCH] mm/oom_kill.c: don't kill TASK_UNINTERRUPTIBLE tasks Oleg Nesterov <oleg@redhat.com> - 2015-09-19 16:50 +0200
Re: [PATCH] mm/oom_kill.c: don't kill TASK_UNINTERRUPTIBLE tasks David Rientjes <rientjes@google.com> - 2015-09-22 01:30 +0200
Re: [PATCH] mm/oom_kill.c: don't kill TASK_UNINTERRUPTIBLE tasks Michal Hocko <mhocko@kernel.org> - 2015-09-19 10:30 +0200
Re: [PATCH] mm/oom_kill.c: don't kill TASK_UNINTERRUPTIBLE tasks Michal Hocko <mhocko@kernel.org> - 2015-09-19 10:30 +0200
Re: [PATCH] mm/oom_kill.c: don't kill TASK_UNINTERRUPTIBLE tasks David Rientjes <rientjes@google.com> - 2015-09-22 01:10 +0200
can't oom-kill zap the victim's memory? Oleg Nesterov <oleg@redhat.com> - 2015-09-19 17:10 +0200
Re: can't oom-kill zap the victim's memory? Oleg Nesterov <oleg@redhat.com> - 2015-09-19 17:20 +0200
Re: can't oom-kill zap the victim's memory? Michal Hocko <mhocko@kernel.org> - 2015-09-19 18:00 +0200
Re: can't oom-kill zap the victim's memory? Oleg Nesterov <oleg@redhat.com> - 2015-09-20 15:20 +0200
Re: can't oom-kill zap the victim's memory? Linus Torvalds <torvalds@linux-foundation.org> - 2015-09-20 00:30 +0200
Re: can't oom-kill zap the victim's memory? Raymond Jennings <shentino@gmail.com> - 2015-09-20 01:10 +0200
Re: can't oom-kill zap the victim's memory? Linus Torvalds <torvalds@linux-foundation.org> - 2015-09-20 01:20 +0200
Re: can't oom-kill zap the victim's memory? Michal Hocko <mhocko@kernel.org> - 2015-09-20 11:40 +0200
Re: can't oom-kill zap the victim's memory? Oleg Nesterov <oleg@redhat.com> - 2015-09-20 15:10 +0200
Re: can't oom-kill zap the victim's memory? Oleg Nesterov <oleg@redhat.com> - 2015-09-20 15:10 +0200
Re: can't oom-kill zap the victim's memory? Linus Torvalds <torvalds@linux-foundation.org> - 2015-09-20 20:10 +0200
Re: can't oom-kill zap the victim's memory? Raymond Jennings <shentino@gmail.com> - 2015-09-20 21:10 +0200
Re: can't oom-kill zap the victim's memory? Oleg Nesterov <oleg@redhat.com> - 2015-09-21 16:10 +0200
Re: can't oom-kill zap the victim's memory? Oleg Nesterov <oleg@redhat.com> - 2015-09-21 15:50 +0200
Re: can't oom-kill zap the victim's memory? Michal Hocko <mhocko@kernel.org> - 2015-09-21 16:30 +0200
Re: can't oom-kill zap the victim's memory? Oleg Nesterov <oleg@redhat.com> - 2015-09-21 17:40 +0200
Re: can't oom-kill zap the victim's memory? Michal Hocko <mhocko@kernel.org> - 2015-09-21 18:20 +0200
Re: can't oom-kill zap the victim's memory? Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2015-09-21 19:00 +0200
Re: can't oom-kill zap the victim's memory? David Rientjes <rientjes@google.com> - 2015-09-22 01:50 +0200
Re: can't oom-kill zap the victim's memory? Linus Torvalds <torvalds@linux-foundation.org> - 2015-09-21 19:00 +0200
Re: can't oom-kill zap the victim's memory? Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2015-09-20 17:00 +0200
Re: can't oom-kill zap the victim's memory? Oleg Nesterov <oleg@redhat.com> - 2015-09-20 17:00 +0200
csiph-web