Message-ID: <803f7ef2-f217-65fe-d0b9-98ae469556fa@collabora.com>
Date:   Tue, 28 Feb 2023 19:20:48 +0500
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Cc:     Muhammad Usama Anjum <usama.anjum@collabora.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>, hpa@zytor.com,
        x86@kernel.org, linux-perf-users@vger.kernel.org,
        linux-kernel@vger.kernel.org, gautham.shenoy@amd.com,
        ananth.narayan@amd.com,
        "kernel@collabora.com" <kernel@collabora.com>
Subject: Re: [PATCH] perf/x86/rapl: Enable Core RAPL for AMD
To:     Stephane Eranian <eranian@google.com>,
        Wyes Karny <wyes.karny@amd.com>
References: <20230217161354.129442-1-wyes.karny@amd.com>
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From:   Muhammad Usama Anjum <usama.anjum@collabora.com>
In-Reply-To: <CABPqkBQ_bSTC-OEe_LrgUrpj2VsseX1ThvO-yLcEtF8vb4+AAw@mail.gmail.com>
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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