Re: [PATCH 5/5] perf, x86: Prefer RDPMC over RDMSR for readingcounters

[Peter Zijlstra]

On Tue, 2012-06-05 at 17:56 -0700, Andi Kleen wrote:
> From: Andi Kleen <ak@xxxxxxxxxxxxxxx>
> 
> 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.
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