Re: [PATCH] perf/x86/rapl: Enable Core RAPL for AMD

[Stephane Eranian <eranian@google.com>]

On Mon, Feb 20, 2023 at 3:45 AM Peter Zijlstra <peterz@infradead.org> wrote:
>
> On Fri, Feb 17, 2023 at 04:13:54PM +0000, Wyes Karny wrote:
> > AMD processors support per-package and per-core energy monitoring
> > through RAPL counters which can be accessed by users running in
> > supervisor mode.
> >
> > Core RAPL counters gives power consumption information per core.  For
> > AMD processors the package level RAPL counter are already exposed to
> > perf. Expose the core level RAPL counters also.
> >
> > sudo perf stat -a --per-core -C 0-127 -e power/energy-cores/
> >
> > Output:
> > S0-D0-C0           2               8.73 Joules power/energy-cores/
> > S0-D0-C1           2               8.73 Joules power/energy-cores/
> > S0-D0-C2           2               8.73 Joules power/energy-cores/
> > S0-D0-C3           2               8.73 Joules power/energy-cores/
> > S0-D0-C4           2               8.73 Joules power/energy-cores/
> >
> > Signed-off-by: Wyes Karny <wyes.karny@amd.com>
> > ---
> >  arch/x86/events/rapl.c | 5 +++--
> >  1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/x86/events/rapl.c b/arch/x86/events/rapl.c
> > index 52e6e7ed4f78..d301bbbc3b93 100644
> > --- a/arch/x86/events/rapl.c
> > +++ b/arch/x86/events/rapl.c
> > @@ -537,7 +537,7 @@ static struct perf_msr intel_rapl_spr_msrs[] = {
> >   * - want to use same event codes across both architectures
> >   */
> >  static struct perf_msr amd_rapl_msrs[] = {
> > -     [PERF_RAPL_PP0]  = { 0, &rapl_events_cores_group, 0, false, 0 },
> > +     [PERF_RAPL_PP0]  = { MSR_AMD_CORE_ENERGY_STATUS, &rapl_events_cores_group, test_msr, false, RAPL_MSR_MASK },
>
> Stephane, this was an oversight?
>
I think it may depend on the CPU model. I remember it returning either
0 or bogus values on my systems. They may have improved that.
The commit msg does not show which CPU model this is run on.

>
> >       [PERF_RAPL_PKG]  = { MSR_AMD_PKG_ENERGY_STATUS,  &rapl_events_pkg_group,   test_msr, false, RAPL_MSR_MASK },
> >       [PERF_RAPL_RAM]  = { 0, &rapl_events_ram_group,   0, false, 0 },
> >       [PERF_RAPL_PP1]  = { 0, &rapl_events_gpu_group,   0, false, 0 },
> > @@ -764,7 +764,8 @@ static struct rapl_model model_spr = {
> >  };
> >
> >  static struct rapl_model model_amd_hygon = {
> > -     .events         = BIT(PERF_RAPL_PKG),
> > +     .events         = BIT(PERF_RAPL_PP0) |
> > +                       BIT(PERF_RAPL_PKG),
> >       .msr_power_unit = MSR_AMD_RAPL_POWER_UNIT,
> >       .rapl_msrs      = amd_rapl_msrs,
> >  };
> > --
> > 2.34.1
> >