Re: [PATCH v3] perf: honoring the architectural performance monitoring version

From: Imre Palik
Date: Thu Jun 18 2015 - 10:25:46 EST

On 06/16/15 11:21, Peter Zijlstra wrote:
> On Mon, Jun 15, 2015 at 04:22:32PM +0200, Imre Palik wrote:
>> From: "Palik, Imre" <imrep@xxxxxxxxx>
>> Architectural performance monitoring version 1 doesn't support fixed
>> counters. Currently, even if a hypervisor advertises support for
>> architectural performance monitoring version 1, perf may still tries to use
>> the fixed counters, as the constraints are set up based on the CPU model.
>> This patch ensures that perf honors the architectural performance
>> monitoring version returned by CPUID, and it only uses the fixed counters
>> for version two and above.
>> Some of the ideas in this patch are coming from Peter Zijlstra.
> What's the difference from -v2? I'm not really seeing it.

I made the mistake of sending two different versions as v2. v3 is the same
as the second v2.

I sent this to clear up possible confusion. Sorry if it caused more of it.
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