Re: [PATCH v1] perf vendor power9 nest metrics: Correct unit from MB to MiB

From: Ian Rogers

Date: Wed Nov 12 2025 - 14:31:35 EST


On Fri, Oct 31, 2025 at 9:26 AM Ian Rogers <irogers@xxxxxxxxxx> wrote:
>
> 6.1e-5 is very close to 1/16384, where 16384 is 2^14, i.e. a power of
> 2. When units are in powers of 2 the IEC unit is MiB (mebibytes)
> rather than MB (megabytes) where the values are powers of 10. This
> patch corrects the unit for uniformity and because such units may be
> pattern matched against.
>
> Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>

Ping.

Thanks,
Ian

> ---
> .../perf/pmu-events/arch/powerpc/power9/nest_metrics.json | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/tools/perf/pmu-events/arch/powerpc/power9/nest_metrics.json b/tools/perf/pmu-events/arch/powerpc/power9/nest_metrics.json
> index 7a5d1bf543f8..8d028a7c2777 100644
> --- a/tools/perf/pmu-events/arch/powerpc/power9/nest_metrics.json
> +++ b/tools/perf/pmu-events/arch/powerpc/power9/nest_metrics.json
> @@ -29,25 +29,25 @@
> "MetricExpr" : "nest_mcs01_imc@PM_MCS01_128B_RD_DISP_PORT01@ + nest_mcs01_imc@PM_MCS01_128B_RD_DISP_PORT23@",
> "MetricName" : "mcs01-read",
> "MetricGroup" : "memory-bandwidth",
> - "ScaleUnit": "6.1e-5MB"
> + "ScaleUnit": "6.1e-5MiB"
> },
> {
> "MetricExpr" : "nest_mcs23_imc@PM_MCS23_128B_RD_DISP_PORT01@ + nest_mcs23_imc@PM_MCS23_128B_RD_DISP_PORT23@",
> "MetricName" : "mcs23-read",
> "MetricGroup" : "memory-bandwidth",
> - "ScaleUnit": "6.1e-5MB"
> + "ScaleUnit": "6.1e-5MiB"
> },
> {
> "MetricExpr" : "nest_mcs01_imc@PM_MCS01_128B_WR_DISP_PORT01@ + nest_mcs01_imc@PM_MCS01_128B_WR_DISP_PORT23@",
> "MetricName" : "mcs01-write",
> "MetricGroup" : "memory-bandwidth",
> - "ScaleUnit": "6.1e-5MB"
> + "ScaleUnit": "6.1e-5MiB"
> },
> {
> "MetricExpr" : "nest_mcs23_imc@PM_MCS23_128B_WR_DISP_PORT01@ + nest_mcs23_imc@PM_MCS23_128B_WR_DISP_PORT23@",
> "MetricName" : "mcs23-write",
> "MetricGroup" : "memory-bandwidth",
> - "ScaleUnit": "6.1e-5MB"
> + "ScaleUnit": "6.1e-5MiB"
> },
> {
> "MetricExpr" : "nest_powerbus0_imc@PM_PB_CYC@",
> --
> 2.51.1.930.gacf6e81ea2-goog
>