Re: [PATCH v4 02/22] perf jevents: Add idle metric for Intel models

[Liang, Kan]

On 2024-09-26 1:50 p.m., Ian Rogers wrote:
> Compute using the msr PMU the percentage of wallclock cycles where the
> CPUs are in a low power state.
> 
> Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
> ---
>  tools/perf/pmu-events/intel_metrics.py | 16 ++++++++++++++--
>  1 file changed, 14 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/perf/pmu-events/intel_metrics.py b/tools/perf/pmu-events/intel_metrics.py
> index 58e23eb48312..f875eb844c78 100755
> --- a/tools/perf/pmu-events/intel_metrics.py
> +++ b/tools/perf/pmu-events/intel_metrics.py
> @@ -1,7 +1,8 @@
>  #!/usr/bin/env python3
>  # SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
> -from metric import (d_ratio, has_event, Event, JsonEncodeMetric, JsonEncodeMetricGroupDescriptions,
> -                    LoadEvents, Metric, MetricGroup, Select)
> +from metric import (d_ratio, has_event, max, Event, JsonEncodeMetric,
> +                    JsonEncodeMetricGroupDescriptions, LoadEvents, Metric,
> +                    MetricGroup, Select)
>  import argparse
>  import json
>  import math
> @@ -11,6 +12,16 @@ import os
>  _args = None
>  interval_sec = Event("duration_time")
>  
> +def Idle() -> Metric:
> +  cyc = Event("msr/mperf/")
> +  tsc = Event("msr/tsc/")
> +  low = max(tsc - cyc, 0)
> +  return Metric(
> +      "idle",
> +      "Percentage of total wallclock cycles where CPUs are in low power state (C1 or deeper sleep state)",
> +      d_ratio(low, tsc), "100%")

I'm not sure if the metrics is correct, especially considering the mperf
is a R/W register. If someone clear the mperf, the restuls must be wrong.

Thanks,
Kan

> +
> +
>  def Rapl() -> MetricGroup:
>    """Processor power consumption estimate.
>  
> @@ -68,6 +79,7 @@ def main() -> None:
>    LoadEvents(directory)
>  
>    all_metrics = MetricGroup("", [
> +      Idle(),
>        Rapl(),
>    ])
>