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Date: Thu, 29 Sep 2011 18:51:48 -0700
From: Tejun Heo <htejun@gmail.com>
To: Michal Hocko <mhocko@suse.cz>
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
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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().  How
urgent is this?  Can we wait for the next merge window?

Thanks.

-- 
tejun