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

[Wyes Karny <wyes.karny@amd.com>]

Hi Muhammad,

On 28 Feb 19:20, Muhammad Usama Anjum wrote:
> 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?

I'm working on the issue reported by Stephane. Will send v2 very soon.

Thanks,
Wyes
> 
> [..]
> 
> >>>> 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