Subject: Re: [PATCH v4 03/48] perf stat: Correct aggregation CPU map
To:     Ian Rogers <irogers@google.com>, Andi Kleen <ak@linux.intel.com>,
        "Jiri Olsa" <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
        Kajol Jain <kjain@linux.ibm.com>,
        "Paul A . Clarke" <pc@us.ibm.com>,
        "Arnaldo Carvalho de Melo" <acme@kernel.org>,
        Riccardo Mancini <rickyman7@gmail.com>,
        Kan Liang <kan.liang@linux.intel.com>,
        Peter Zijlstra <peterz@infradead.org>,
        "Ingo Molnar" <mingo@redhat.com>,
        Mark Rutland <mark.rutland@arm.com>,
        "Alexander Shishkin" <alexander.shishkin@linux.intel.com>,
        <linux-perf-users@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        "Vineet Singh" <vineet.singh@intel.com>,
        James Clark <james.clark@arm.com>,
        "Mathieu Poirier" <mathieu.poirier@linaro.org>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Mike Leach <mike.leach@linaro.org>,
        Leo Yan <leo.yan@linaro.org>, <coresight@lists.linaro.org>,
        <linux-arm-kernel@lists.infradead.org>, <zhengjun.xing@intel.com>
CC:     <eranian@google.com>
References: <20220105061351.120843-1-irogers@google.com>
 <20220105061351.120843-4-irogers@google.com>
From:   John Garry <john.garry@huawei.com>
Message-ID: <1ae917ec-4d32-4ee7-0948-f91eb3bf35fb@huawei.com>
Date:   Mon, 10 Jan 2022 18:43:08 +0000
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On 05/01/2022 06:13, Ian Rogers wrote:
> Switch the perf_cpu_map in aggr_update_shadow from
> the evlist to the counter's cpu map, so the index is appropriate. This
> addresses a problem where uncore counts, with a cpumap like:
> $ cat /sys/devices/uncore_imc_0/cpumask
> 0,18
> Don't aggregate counts in CPUs based on the index of those values in the
> cpumap (0 and 1) but on the actual CPU (0 and 18). Thereby correcting
> metric calculations in per-socket mode for counters without a full
> cpumask.
> 
> On a SkylakeX with a tweaked DRAM_BW_Use metric, to remove unnecessary
> scaling, this gives:
> 
> Before:
> $ /perf stat --per-socket -M DRAM_BW_Use -I 1000
>       1.001102293 S0        1              27.01 MiB  uncore_imc/cas_count_write/ #   103.00 DRAM_BW_Use
>       1.001102293 S0        1              30.22 MiB  uncore_imc/cas_count_read/
>       1.001102293 S0        1      1,001,102,293 ns   duration_time
>       1.001102293 S1        1              20.10 MiB  uncore_imc/cas_count_write/ #     0.00 DRAM_BW_Use
>       1.001102293 S1        1              32.74 MiB  uncore_imc/cas_count_read/
>       1.001102293 S1        0      <not counted> ns   duration_time
>       2.003517973 S0        1              83.04 MiB  uncore_imc/cas_count_write/ #   920.00 DRAM_BW_Use
>       2.003517973 S0        1             145.95 MiB  uncore_imc/cas_count_read/
>       2.003517973 S0        1      1,002,415,680 ns   duration_time
>       2.003517973 S1        1             302.45 MiB  uncore_imc/cas_count_write/ #     0.00 DRAM_BW_Use
>       2.003517973 S1        1             290.99 MiB  uncore_imc/cas_count_read/
>       2.003517973 S1        0      <not counted> ns   duration_time
> 
> After:
> $ perf stat --per-socket -M DRAM_BW_Use -I 1000
>       1.001080840 S0        1              24.96 MiB  uncore_imc/cas_count_write/ #    54.00 DRAM_BW_Use
>       1.001080840 S0        1              33.64 MiB  uncore_imc/cas_count_read/
>       1.001080840 S0        1      1,001,080,840 ns   duration_time
>       1.001080840 S1        1              42.43 MiB  uncore_imc/cas_count_write/ #    84.00 DRAM_BW_Use
>       1.001080840 S1        1              47.05 MiB  uncore_imc/cas_count_read/
>       1.001080840 S1        0      <not counted> ns   duration_time
> 
> Signed-off-by: Ian Rogers<irogers@google.com>

Tested-by: John Garry <john.garry@huawei.com>