Re: [RFC PATCH v2] perf Documentation: Describe the PMU naming convention

[Ian Rogers]

On Thu, Jun 6, 2024 at 11:15 AM Liang, Kan <kan.liang@xxxxxxxxxxxxxxx> wrote:
>
>
>
> On 2024-06-06 12:49 a.m., Ian Rogers wrote:
> > It is an existing convention to use suffixes with PMU names. Try to
> > capture that convention so that future PMU devices may adhere to it.
> >
> > The name of the file and date within the file try to follow existing
> > conventions, particularly sysfs-bus-event_source-devices-events.
> >
> > Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
> > Reviewed-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> > ---
> >  .../testing/sysfs-bus-event_source-devices    | 24 +++++++++++++++++++
> >  1 file changed, 24 insertions(+)
> >  create mode 100644 Documentation/ABI/testing/sysfs-bus-event_source-devices
> >
>
> Reviewed-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>

Thanks for all the reviews. Could we land this?

Thanks,
Ian

> > diff --git a/Documentation/ABI/testing/sysfs-bus-event_source-devices b/Documentation/ABI/testing/sysfs-bus-event_source-devices
> > new file mode 100644
> > index 000000000000..79b268319df1
> > --- /dev/null
> > +++ b/Documentation/ABI/testing/sysfs-bus-event_source-devices
> > @@ -0,0 +1,24 @@
> > +What: /sys/bus/event_source/devices/<pmu>
> > +Date: 2014/02/24
> > +Contact:     Linux kernel mailing list <linux-kernel@xxxxxxxxxxxxxxx>
> > +Description: Performance Monitoring Unit (<pmu>)
> > +
> > +             Each <pmu> directory, for a PMU device, is a name
> > +             optionally followed by an underscore and then either a
> > +             decimal or hexadecimal number. For example, cpu is a
> > +             PMU name without a suffix as is intel_bts,
> > +             uncore_imc_0 is a PMU name with a 0 numeric suffix,
> > +             ddr_pmu_87e1b0000000 is a PMU name with a hex
> > +             suffix. The hex suffix must be more than two
> > +             characters long to avoid ambiguity with PMUs like the
> > +             S390 cpum_cf.
> > +
> > +             Tools can treat PMUs with the same name that differ by
> > +             suffix as instances of the same PMU for the sake of,
> > +             for example, opening an event. For example, the PMUs
> > +             uncore_imc_free_running_0 and
> > +             uncore_imc_free_running_1 have an event data_read;
> > +             opening the data_read event on a PMU specified as
> > +             uncore_imc_free_running should be treated as opening
> > +             the data_read event on PMU uncore_imc_free_running_0
> > +             and PMU uncore_imc_free_running_1.