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Date: Fri, 6 Dec 2013 16:52:38 +0100
From: Oleg Nesterov <oleg@redhat.com>
To: David Rientjes <rientjes@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>, Michal Hocko <mhocko@suse.cz>,
        William Dauchy <wdauchy@gmail.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        "Ma, Xindong" <xindong.ma@intel.com>,
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        linux-kernel@vger.kernel.org, Peter Zijlstra <peterz@infradead.org>,
        gregkh@linuxfoundation.org, "Tu, Xiaobing" <xiaobing.tu@intel.com>,
        azurIt <azurit@pobox.sk>, Sameer Nanda <snanda@chromium.org>
Subject: Re: [PATCH] Fix race between oom kill and task exit
Message-ID: <20131206155238.GA6676@redhat.com>
References: <3917C05D9F83184EAA45CE249FF1B1DD0253093A@SHSMSX103.ccr.corp.intel.com> <20131128063505.GN3556@cmpxchg.org> <CAJ75kXZXxCMgf8=pghUWf=W9EKf3Z4nzKKy=CAn+7keVF_DCRA@mail.gmail.com> <20131128120018.GL2761@dhcp22.suse.cz> <20131128183830.GD20740@redhat.com> <20131202141203.GA31402@redhat.com> <alpine.DEB.2.02.1312041655370.13608@chino.kir.corp.google.com> <20131205172931.GA26018@redhat.com> <alpine.DEB.2.02.1312051531330.7717@chino.kir.corp.google.com> <20131206151944.GC2674@redhat.com>
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On 12/06, Oleg Nesterov wrote:
>
> And this is risky. For example, 1/4 depends on (at least) another patch
> I sent in preparation for this change, commit 81907739851
> "kernel/fork.c:copy_process(): don't add the uninitialized
> child to thread/task/pid lists", perhaps on something else.

Hmm. not too much actually, I re-checked v3.10:kernel/copy_process.c.
Yes, list_add(thread_node)) in copy_process() can add the new thread
with the wrong pids, but somehow I forgot that list_add(thread_group)
in v3.10 has the same problem, so this probably doesn't matter and
we can safely backport this change.

> So personally I'd prefer to simply send the workaround for stable.

Yes, anyway, bacause I will sleep better ;)

But OK, if you think it would be better to mark 1-4 series I sent
for stable - I won't argue.

Oleg.