Re: [PATCH v2 1/2] perf tools: add event modifier to requestexclusive PMU access

From: Stephane Eranian
Date: Mon Oct 22 2012 - 11:44:01 EST


On Mon, Oct 22, 2012 at 5:39 PM, Andi Kleen <ak@xxxxxxxxxxxxxxx> wrote:
>> But maybe you're talking about a generic event exports in
>> /sys/device/cpu/events.
>> But why would I expose prec_dist there. And under what name?
>
> I already exposed it in the Haswell patchkit (instructions-p)
>
> I also exposed precise there so that some events can be forced PEBS
>
> If you want to expose it on Sandy Bridge too you need to add the
> event to the user tool grammar, like I did for precise.
>
> Then user can just use
>
> perf record -e instructions-p ...
>
> and the kernel does automagically the right thing.
>
Ok, I understand now.
But I am wondering what would be the meaning of:

$ perf stat -e instructions-p ...

I know the answer, because I know what's going on under the
hood. But what about the average user?
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