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

[Ian Rogers]

On Wed, Nov 12, 2025 at 11:31 AM Ian Rogers <irogers@xxxxxxxxxx> wrote:
>
> 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.

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
> >