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Date: Tue, 29 Oct 2013 11:21:31 +0100
From: Peter Zijlstra <peterz@infradead.org>
To: Victor Kaplansky <VICTORK@il.ibm.com>
Subject: Re: perf events ring buffer memory barrier on powerpc
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Cc: Michael Neuling <mikey@neuling.org>,
 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>,
 Oleg Nesterov <oleg@redhat.com>, LKML <linux-kernel@vger.kernel.org>,
 Linux PPC dev <linuxppc-dev@ozlabs.org>, Anton Blanchard <anton@samba.org>,
 Frederic Weisbecker <fweisbec@gmail.com>,
 "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
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On Mon, Oct 28, 2013 at 10:58:58PM +0200, Victor Kaplansky wrote:
> Oleg Nesterov <oleg@redhat.com> wrote on 10/28/2013 10:17:35 PM:
> 
> >       mb();   // XXXXXXXX: do we really need it? I think yes.
> 
> Oh, it is hard to argue with feelings. Also, it is easy to be on
> conservative side and put the barrier here just in case.

I'll make it a full mb for now and too am curious to see the end of this
discussion explaining things ;-)