Re: [PATCH V2 1/1] perf/x86: Add Intel power cstate PMUs support

[Stephane Eranian]

On Thu, Aug 6, 2015 at 11:52 AM, Liang, Kan <kan.liang@xxxxxxxxx> wrote:
>
>
>> >> +static cpumask_t power_cstate_core_cpu_mask;
>> >
>> > That one typically does not need a cpumask.
>> >
>> You need to pick one CPU out of the multi-core. But it is for client parts
>> thus there is only one socket. At least this is my understanding.
>>
>
> CORE_C*_RESIDENCY are available for physical processor core.
> So logical processor in same physical processor core share the same
> counter.
> I think we need the cpumask to identify the default logical processor which
> do counting.
>
Did you restrict these events to system-wide mode only?

>> >
>> I understand that these metrics are useful and needed however if I look at
>> the broader picture I see many PMUs doing similar things or appearing
>> different when they are actually very close. It would be nice to have a
>> more unified approach. You have RAPL (client, server) which appears as
>> the power PMU. You have the PCU uncore on servers which also provides
>> C-state residency info. Yet, all these appear differently and expose events
>> with different names.
>> I think we could benefit from a more unifie approach here such that you
>> would be able to do
>>
>> $    perf stat -a -e power/c6-residency/, power/energy-pkg/
>>
>> on client and server without having to change the pmu name of the event
>> names.
>
> Yes, I agree. I'll think about it.
>
> Thanks,
> Kan
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/