Subject: Re: [BUG] "sched: Remove rq->lock from the first half of ttwu()"
 locks up on ARM
From: Peter Zijlstra <peterz@infradead.org>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Marc Zyngier <Marc.Zyngier@arm.com>, Yong Zhang <yong.zhang0@gmail.com>,
        Ingo Molnar <mingo@elte.hu>, Frank Rowand <frank.rowand@am.sony.com>,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org
In-Reply-To: <20110526154508.GA13788@redhat.com>
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Date: Thu, 26 May 2011 17:59:44 +0200
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On Thu, 2011-05-26 at 17:45 +0200, Oleg Nesterov wrote:
> Stupid question. Can't we fix this problem if we do
> 
>         -       if (p == current)
>         +       if (cpu == raw_smp_processor_id())
> 
> ?
> 
> I forgot the rules... but iirc task_cpu(p) can't be changed under us?

Easy enough to test.. brain gave out again,. hold on ;-)

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