Messages in this thread Patch in this message | | | Subject | Re: [PATCH V5 04/25] perf/x86/intel: Hybrid PMU support for perf capabilities | From | "Liang, Kan" <> | Date | Thu, 8 Apr 2021 13:40:41 -0400 |
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On 4/8/2021 1:00 PM, Peter Zijlstra wrote: > On Mon, Apr 05, 2021 at 08:10:46AM -0700, kan.liang@linux.intel.com wrote: >> +#define is_hybrid() (!!x86_pmu.num_hybrid_pmus) > > Given this is sprinkled all over the place, can you make this a > static_key_false + static_branch_unlikely() such that the hybrid case is > out-of-line? >
Sure, I will add a new static_key_false "perf_is_hybrid" to indicate a hybrid system as below (not test yet).
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c index f8d1222..bd6412e 100644 --- a/arch/x86/events/core.c +++ b/arch/x86/events/core.c @@ -54,6 +54,7 @@ DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events) = {
DEFINE_STATIC_KEY_FALSE(rdpmc_never_available_key); DEFINE_STATIC_KEY_FALSE(rdpmc_always_available_key); +DEFINE_STATIC_KEY_FALSE(perf_is_hybrid);
/* * This here uses DEFINE_STATIC_CALL_NULL() to get a static_call defined diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c index 2b553d9..7cef3cd 100644 --- a/arch/x86/events/intel/core.c +++ b/arch/x86/events/intel/core.c @@ -6119,6 +6119,7 @@ __init int intel_pmu_init(void) GFP_KERNEL); if (!x86_pmu.hybrid_pmu) return -ENOMEM; + static_branch_enable(&perf_is_hybrid); x86_pmu.num_hybrid_pmus = X86_HYBRID_NUM_PMUS;
x86_pmu.late_ack = true; diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h index bfbecde..d6383d1 100644 --- a/arch/x86/events/perf_event.h +++ b/arch/x86/events/perf_event.h @@ -663,8 +663,8 @@ static __always_inline struct x86_hybrid_pmu *hybrid_pmu(struct pmu *pmu) return container_of(pmu, struct x86_hybrid_pmu, pmu); }
-/* The number of hybrid PMUs implies whether it's a hybrid system */ -#define is_hybrid() (!!x86_pmu.num_hybrid_pmus) +extern struct static_key_false perf_is_hybrid; +#define is_hybrid() static_branch_unlikely(&perf_is_hybrid)
#define hybrid(_pmu, _field) \ ({ \ Thanks, Kan
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