Re: [PATCH] perf/x86/rapl: Enable Core RAPL for AMD

[Muhammad Usama Anjum]

On 2/21/23 1:50 PM, Stephane Eranian wrote:
> Hi,
> 
> Testing Wyes' patch for energy-cores on Zen3 server loaded with triad
> bench on socket0:
> 
> $ perf stat --per-core -a -C0-63 -I 1000 -e
> power/energy-cores/,power/energy-pkg/
> #           time core               cpus             counts   unit events
>      1.001019203 S0-D0-C0              1               1.28 Joules
> power/energy-cores/
>      1.001019203 S0-D0-C0              1             231.38 Joules
> power/energy-pkg/
>      1.001019203 S0-D0-C1              1   4,294,967,130.96 Joules
> power/energy-cores/
>      1.001019203 S0-D0-C1              1             231.38 Joules
> power/energy-pkg/
>      1.001019203 S0-D0-C2              1   4,294,967,126.23 Joules
> power/energy-cores/
>      1.001019203 S0-D0-C2              1             231.38 Joules
> power/energy-pkg/
>      1.001019203 S0-D0-C3              1   4,294,967,122.50 Joules
> power/energy-cores/
>      1.001019203 S0-D0-C3              1             231.38 Joules
> power/energy-pkg/
>      1.001019203 S0-D0-C4              1   4,294,967,129.92 Joules
> power/energy-cores/
>      1.001019203 S0-D0-C4              1             231.38 Joules
> power/energy-pkg/
>      1.001019203 S0-D0-C5              1   4,294,967,121.49 Joules
> power/energy-cores/
>      1.001019203 S0-D0-C5              1             231.39 Joules
> power/energy-pkg/
> 
> I think the result of energy-cores is not reliable and I think that is
> why I did not
> include it in the patch.
> 
> Could also be a problem with the kernel code, but I don't know why it would only
> impact energy-cores given energy-pkg looks reasonable here.
> 

I'm getting consistent per core energy measurements on AMD Custom APU 405.
Probably consistency depends on the chip.

sudo perf stat -a --per-core -C 0-7 -e power/energy-cores/

 Performance counter stats for 'system wide':

 S0-D0-C0           2               0.51 Joules power/energy-cores/
 S0-D0-C1           2               0.51 Joules power/energy-cores/
 S0-D0-C2           2               0.51 Joules power/energy-cores/
 S0-D0-C3           2               0.51 Joules power/energy-cores/

What is the fate of this patch now?

[..]

>>>> Stephane, this was an oversight?
>>>>
>>> I think it may depend on the CPU model. I remember it returning either
>>> 0 or bogus values on my systems. They may have improved that.
>>> The commit msg does not show which CPU model this is run on.
>>
>> I've tested this on Zen 2, 3 and 4 server systems.
>>
>> Thanks,
>> Wyes

-- 
BR,
Muhammad Usama Anjum