[PATCH 2/4] perf/x86: Remove unused PERF_PMU_CAP_HETEROGENEOUS_CPUS capability

James Clark posted 4 patches 2 years, 7 months ago
There is a newer version of this series
[PATCH 2/4] perf/x86: Remove unused PERF_PMU_CAP_HETEROGENEOUS_CPUS capability
Posted by James Clark 2 years, 7 months ago
Since commit bd2756811766 ("perf: Rewrite core context handling") the
relationship between perf_event_context and PMUs has changed so that
the error scenario that PERF_PMU_CAP_HETEROGENEOUS_CPUS originally
silenced no longer exists.

Remove the capability to avoid confusion that it actually influences
any perf core behavior. This change should be a no-op.

Signed-off-by: James Clark <james.clark@arm.com>
---
 arch/x86/events/core.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 9d248703cbdd..2353aaf0b248 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -2168,7 +2168,6 @@ static int __init init_hw_perf_events(void)
 			hybrid_pmu->pmu = pmu;
 			hybrid_pmu->pmu.type = -1;
 			hybrid_pmu->pmu.attr_update = x86_pmu.attr_update;
-			hybrid_pmu->pmu.capabilities |= PERF_PMU_CAP_HETEROGENEOUS_CPUS;
 			hybrid_pmu->pmu.capabilities |= PERF_PMU_CAP_EXTENDED_HW_TYPE;
 
 			err = perf_pmu_register(&hybrid_pmu->pmu, hybrid_pmu->name,
-- 
2.34.1
Re: [PATCH 2/4] perf/x86: Remove unused PERF_PMU_CAP_HETEROGENEOUS_CPUS capability
Posted by Ian Rogers 2 years, 7 months ago
On Mon, Jul 10, 2023 at 5:22 AM James Clark <james.clark@arm.com> wrote:
>
> Since commit bd2756811766 ("perf: Rewrite core context handling") the
> relationship between perf_event_context and PMUs has changed so that
> the error scenario that PERF_PMU_CAP_HETEROGENEOUS_CPUS originally
> silenced no longer exists.
>
> Remove the capability to avoid confusion that it actually influences
> any perf core behavior. This change should be a no-op.
>
> Signed-off-by: James Clark <james.clark@arm.com>

Acked-by: Ian Rogers <irogers@google.com>

Thanks,
Ian

> ---
>  arch/x86/events/core.c | 1 -
>  1 file changed, 1 deletion(-)
>
> diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
> index 9d248703cbdd..2353aaf0b248 100644
> --- a/arch/x86/events/core.c
> +++ b/arch/x86/events/core.c
> @@ -2168,7 +2168,6 @@ static int __init init_hw_perf_events(void)
>                         hybrid_pmu->pmu = pmu;
>                         hybrid_pmu->pmu.type = -1;
>                         hybrid_pmu->pmu.attr_update = x86_pmu.attr_update;
> -                       hybrid_pmu->pmu.capabilities |= PERF_PMU_CAP_HETEROGENEOUS_CPUS;
>                         hybrid_pmu->pmu.capabilities |= PERF_PMU_CAP_EXTENDED_HW_TYPE;
>
>                         err = perf_pmu_register(&hybrid_pmu->pmu, hybrid_pmu->name,
> --
> 2.34.1
>