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

Peter Zijlstra
2012-06-06T10:46:28Z

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.