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Message-ID: <1338979579.2749.95.camel@twins>
Subject: Re: [PATCH 5/5] perf, x86: Prefer RDPMC over RDMSR for reading
 counters
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Andi Kleen <andi@firstfloor.org>
Cc: linux-kernel@vger.kernel.org, eranian@google.com,
        Andi Kleen <ak@linux.intel.com>
Date: Wed, 06 Jun 2012 12:46:19 +0200
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On Tue, 2012-06-05 at 17:56 -0700, Andi Kleen wrote:
> From: Andi Kleen <ak@linux.intel.com>
> 
> RDPMC is much faster than RDMSR for reading performance counters,
> since it's not serializing.  Use it if possible in the perf handler.
> 
> Only tested on Sandy Bridge, so I only enabled it there so far.

That's just stupid.. I took Vince's patch from a while back.