From: Michal Hocko <mhocko@suse.cz>
To: Tejun Heo <htejun@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>,
David Rientjes <rientjes@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Konstantin Khlebnikov <khlebnikov@openvz.org>,
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
"Rafael J. Wysocki" <rjw@sisk.pl>,
Rusty Russell <rusty@rustcorp.com.au>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [patch] oom: thaw threads if oom killed thread is frozen before deferring
Date: Fri, 30 Sep 2011 09:41:25 +0200 [thread overview]
Message-ID: <20110930074125.GB32134@tiehlicka.suse.cz> (raw)
In-Reply-To: <20110930015148.GD10425@mtj.dyndns.org>
On Thu 29-09-11 18:51:48, Tejun Heo wrote:
> Hello,
>
> On Thu, Sep 29, 2011 at 08:00:21PM +0200, Michal Hocko wrote:
> > > I meant, oom_kill can do this before thaw thaw_process(), afaics
> > > this should fix the particular race you described (but not others).
> >
> > This is what the follow up fix from David is doing. Check frozen in
> > select_bad_process if the task is TIF_MEMDIE and thaw the process.
> >
> > And it seems that the David's follow up fix is sufficient so let's leave
> > refrigerator alone.
> > Or am I still missing something?
>
> With pending freezer changes, allowing TIF_MEMDIE tasks to exit
> freezer by modifying freezing() shouldn't be difficult, which should
> be race-free and much simpler than diddling with thaw_task().
Will the rework help with the initial problem of unkillable OOM selected
frozen tasks or it will just help with other races that might be present
with the patch? In other words will this work deprecate the 2 patches
sent earlier in this thread?
> How urgent is this? Can we wait for the next merge window?
Yes, I think we can wait some more.
>
> Thanks.
>
> --
> tejun
>
> --
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--
Michal Hocko
SUSE Labs
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next prev parent reply other threads:[~2011-09-30 7:41 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-27 8:09 [PATCH 0/2] oom: fix livelock when frozen task is selected Michal Hocko
2011-09-27 6:56 ` [PATCH 1/2] lguest: move process freezing before pending signals check Michal Hocko
2011-10-12 6:55 ` Michal Hocko
2011-10-12 23:57 ` Rusty Russell
2011-10-13 5:48 ` Michal Hocko
2011-09-27 8:01 ` [PATCH 2/2] oom: do not live lock on frozen tasks Michal Hocko
2011-09-27 18:35 ` [patch] oom: thaw threads if oom killed thread is frozen before deferring David Rientjes
2011-09-28 10:44 ` Michal Hocko
2011-09-29 11:51 ` Michal Hocko
2011-09-29 12:05 ` Oleg Nesterov
2011-09-29 13:02 ` Michal Hocko
2011-09-29 16:32 ` Michal Hocko
2011-09-29 16:37 ` Oleg Nesterov
2011-09-29 18:00 ` Michal Hocko
2011-09-30 1:51 ` Tejun Heo
2011-09-30 7:41 ` Michal Hocko [this message]
2011-09-30 7:46 ` Tejun Heo
2011-09-30 8:04 ` Michal Hocko
2011-09-30 15:30 ` Oleg Nesterov
2011-10-28 22:23 ` [PATCH 2/2] oom: do not live lock on frozen tasks Andrew Morton
2011-10-29 9:01 ` Michal Hocko
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