Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1227268 > unrolled thread

[PATCH] mm/oom_kill.c: don't kill TASK_UNINTERRUPTIBLE tasks

Started byKyle Walker <kwalker@redhat.com>
First post2015-09-17 20:10 +0200
Last post2015-09-20 17:00 +0200
Articles 2 on this page of 42 — 8 participants

Back to article view | Back to linux.kernel

Contents

  [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

Page 3 of 3 — ← Prev page 1 2 [3]

#1228894 — Re: can't oom-kill zap the victim's memory?

FromTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Date2015-09-20 17:00 +0200
SubjectRe: can't oom-kill zap the victim's memory?
Message-ID<qaOfT-2Yb-1@gated-at.bofh.it>
In reply to#1228457
Oleg Nesterov wrote:
> 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.
> 
> And there are other potential reasons for deadlock.
> 
> Stupid idea. Can't we help the memory hog to free its memory? This is
> orthogonal to other improvements we can do.

So, we are trying to release memory without waiting for arriving at
exit_mm() from do_exit(), right? If it works, it will be a simple and
small change that will be easy to backport.

The idea is that since fatal_signal_pending() tasks no longer return to
user space, we can release memory allocated for use by user space, right?

Then, I think that this approach can be applied to not only OOM-kill case
but also regular kill(pid, SIGKILL) case (i.e. kick from signal_wake_up(1)
or somewhere?). A dedicated kernel thread (not limited to OOM-kill purpose)
scans for fatal_signal_pending() tasks and release that task's memory.
--
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/

[toc] | [prev] | [next] | [standalone]

#1228895 — Re: can't oom-kill zap the victim's memory?

FromOleg Nesterov <oleg@redhat.com>
Date2015-09-20 17:00 +0200
SubjectRe: can't oom-kill zap the victim's memory?
Message-ID<qaOfT-2Yb-5@gated-at.bofh.it>
In reply to#1228894
On 09/20, Tetsuo Handa wrote:
>
> Oleg Nesterov wrote:
> > 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.
> >
> > And there are other potential reasons for deadlock.
> >
> > Stupid idea. Can't we help the memory hog to free its memory? This is
> > orthogonal to other improvements we can do.
>
> So, we are trying to release memory without waiting for arriving at
> exit_mm() from do_exit(), right? If it works, it will be a simple and
> small change that will be easy to backport.
>
> The idea is that since fatal_signal_pending() tasks no longer return to
> user space, we can release memory allocated for use by user space, right?

Yes.

> Then, I think that this approach can be applied to not only OOM-kill case
> but also regular kill(pid, SIGKILL) case (i.e. kick from signal_wake_up(1)
> or somewhere?).

I don't think so... but we might want to do this if (say) we are not going
to kill someone else because fatal_signal_pending(current).

> A dedicated kernel thread (not limited to OOM-kill purpose)
> scans for fatal_signal_pending() tasks and release that task's memory.

Perhaps a dedicated kernel thread makes sense (see other emails),
but I don't think it should scan the killed threads. oom-kill should
kict it.

Anyway, let me repeat there are a lot of details we might want to
discuss. But the initial changes should be simple as possible, imo.

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/

[toc] | [prev] | [standalone]

Page 3 of 3 — ← Prev page 1 2 [3]

Back to top | Article view | linux.kernel

csiph-web