Re: [PATCH v4] perf/x86/rapl: Fix the energy-pkg event for AMD CPUs

Ingo Molnar
2024-09-06T08:12:33Z

* Dhananjay Ugwekar <Dhananjay.Ugwekar@amd.com> wrote:

> After commit ("x86/cpu/topology: Add support for the AMD 0x80000026 leaf"),
> on AMD processors that support extended CPUID leaf 0x80000026, the
> topology_die_cpumask() and topology_logical_die_id() macros, no longer
> return the package cpumask and package id, instead they return the CCD
> (Core Complex Die) mask and id respectively. This leads to the energy-pkg
> event scope to be modified to CCD instead of package.
>
> So, change the PMU scope for AMD and Hygon back to package.
>
> On a 12 CCD 1 Package AMD Zen4 Genoa machine:
>
> Before:
> $ cat /sys/devices/power/cpumask
> 0,8,16,24,32,40,48,56,64,72,80,88.
>
> The expected cpumask here is supposed to be just "0", as it is a package
> scope event, only one CPU will be collecting the event for all the CPUs in
> the package.
>
> After:
> $ cat /sys/devices/power/cpumask
> 0
>
> Signed-off-by: Dhananjay Ugwekar <Dhananjay.Ugwekar@amd.com>
> ---
> v3 Link: https://lore.kernel.org/all/20240904100934.3260-1-Dhananjay.Ugwekar@amd.com/
>
> Changes from v3:
> * Move the rapl_pmu_is_pkg_scope() check before the memory allocation for rapl_pmus
>
> tip/master + PMU scope patchset [1] to be taken as base for testing this patch.

> @@ -643,9 +672,10 @@ static int __init init_rapl_pmus(void)
> rapl_pmus->pmu.start = rapl_pmu_event_start;
> rapl_pmus->pmu.stop = rapl_pmu_event_stop;
> rapl_pmus->pmu.read = rapl_pmu_event_read;
> + rapl_pmus->pmu.scope = rapl_pmu_scope;
> rapl_pmus->pmu.module = THIS_MODULE;
> - rapl_pmus->pmu.scope = PERF_PMU_SCOPE_DIE;
> rapl_pmus->pmu.capabilities = PERF_PMU_CAP_NO_EXCLUDE;
> +
> return 0;
> }

This chunk doesn't apply to perf/urgent.

Thanks,

Ingo