Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <20230711100218.1651995-1-james.clark@arm.com> <20230711100218.1651995-4-james.clark@arm.com>
In-Reply-To: <20230711100218.1651995-4-james.clark@arm.com>
From:   Ian Rogers <irogers@google.com>
Date:   Tue, 11 Jul 2023 17:43:25 -0700
Message-ID: <CAP-5=fUWV8Gq3cHV6h+x+5qNZhxj06q5KhniOnf2LoTsDBpNow@mail.gmail.com>
Subject: Re: [PATCH v3 3/5] perf vendor events arm64: Update scale units and
 descriptions of common topdown metrics
To:     James Clark <james.clark@arm.com>
Cc:     linux-perf-users@vger.kernel.org, renyu.zj@linux.alibaba.com,
        john.g.garry@oracle.com, namhyung@kernel.org, acme@kernel.org,
        Will Deacon <will@kernel.org>,
        Mike Leach <mike.leach@linaro.org>,
        Leo Yan <leo.yan@linaro.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@kernel.org>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Nick Forrington <nick.forrington@arm.com>,
        Ilkka Koskinen <ilkka@os.amperecomputing.com>,
        Kan Liang <kan.liang@linux.intel.com>,
        Kajol Jain <kjain@linux.ibm.com>,
        Thomas Richter <tmricht@linux.ibm.com>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

On Tue, Jul 11, 2023 at 3:02=E2=80=AFAM James Clark <james.clark@arm.com> w=
rote:
>
> Metrics will be published here [1] going forwards, but they have
> slightly different scale units. To allow autogenerated metrics to be
> added more easily, update the scale units to match.
>
> The more detailed descriptions have also been taken and added to the
> common file.
>
> [1]: https://gitlab.arm.com/telemetry-solution/telemetry-solution/-/tree/=
main/data/pmu/cpu/
> Signed-off-by: James Clark <james.clark@arm.com>

Acked-by: Ian Rogers <irogers@google.com>

Thanks,
Ian

> ---
>  tools/perf/pmu-events/arch/arm64/sbsa.json | 24 +++++++++++-----------
>  1 file changed, 12 insertions(+), 12 deletions(-)
>
> diff --git a/tools/perf/pmu-events/arch/arm64/sbsa.json b/tools/perf/pmu-=
events/arch/arm64/sbsa.json
> index f90b338261ac..4eed79a28f6e 100644
> --- a/tools/perf/pmu-events/arch/arm64/sbsa.json
> +++ b/tools/perf/pmu-events/arch/arm64/sbsa.json
> @@ -1,34 +1,34 @@
>  [
>      {
> -        "MetricExpr": "stall_slot_frontend / (#slots * cpu_cycles)",
> -        "BriefDescription": "Frontend bound L1 topdown metric",
> +        "MetricExpr": "100 * (stall_slot_frontend / (#slots * cpu_cycles=
))",
> +        "BriefDescription": "This metric is the percentage of total slot=
s that were stalled due to resource constraints in the frontend of the proc=
essor.",
>          "DefaultMetricgroupName": "TopdownL1",
>          "MetricGroup": "Default;TopdownL1",
>          "MetricName": "frontend_bound",
> -        "ScaleUnit": "100%"
> +        "ScaleUnit": "1percent of slots"
>      },
>      {
> -        "MetricExpr": "(1 - op_retired / op_spec) * (1 - stall_slot / (#=
slots * cpu_cycles))",
> -        "BriefDescription": "Bad speculation L1 topdown metric",
> +        "MetricExpr": "100 * ((1 - op_retired / op_spec) * (1 - stall_sl=
ot / (#slots * cpu_cycles)))",
> +        "BriefDescription": "This metric is the percentage of total slot=
s that executed operations and didn't retire due to a pipeline flush.\nThis=
 indicates cycles that were utilized but inefficiently.",
>          "DefaultMetricgroupName": "TopdownL1",
>          "MetricGroup": "Default;TopdownL1",
>          "MetricName": "bad_speculation",
> -        "ScaleUnit": "100%"
> +        "ScaleUnit": "1percent of slots"
>      },
>      {
> -        "MetricExpr": "(op_retired / op_spec) * (1 - stall_slot / (#slot=
s * cpu_cycles))",
> -        "BriefDescription": "Retiring L1 topdown metric",
> +        "MetricExpr": "100 * ((op_retired / op_spec) * (1 - stall_slot /=
 (#slots * cpu_cycles)))",
> +        "BriefDescription": "This metric is the percentage of total slot=
s that retired operations, which indicates cycles that were utilized effici=
ently.",
>          "DefaultMetricgroupName": "TopdownL1",
>          "MetricGroup": "Default;TopdownL1",
>          "MetricName": "retiring",
> -        "ScaleUnit": "100%"
> +        "ScaleUnit": "1percent of slots"
>      },
>      {
> -        "MetricExpr": "stall_slot_backend / (#slots * cpu_cycles)",
> -        "BriefDescription": "Backend Bound L1 topdown metric",
> +        "MetricExpr": "100 * (stall_slot_backend / (#slots * cpu_cycles)=
)",
> +        "BriefDescription": "This metric is the percentage of total slot=
s that were stalled due to resource constraints in the backend of the proce=
ssor.",
>          "DefaultMetricgroupName": "TopdownL1",
>          "MetricGroup": "Default;TopdownL1",
>          "MetricName": "backend_bound",
> -        "ScaleUnit": "100%"
> +        "ScaleUnit": "1percent of slots"
>      }
>  ]
> --
> 2.34.1
>