Messages in this thread Patch in this message | | | From | Kim Phillips <> | Subject | [PATCH] perf/x86/amd: Use faster rdpmc instruction when waiting for overflow | Date | Tue, 16 Nov 2021 11:07:54 -0600 |
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The relatively new amd_pmu_wait_on_overflow uses rdmsr. Update it to use the faster rdpmc instruction.
Signed-off-by: Kim Phillips <kim.phillips@amd.com> --- arch/x86/events/amd/core.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c index 9687a8aef01c..c36cb0c6f9e1 100644 --- a/arch/x86/events/amd/core.c +++ b/arch/x86/events/amd/core.c @@ -587,6 +587,8 @@ static void amd_pmu_cpu_dead(int cpu) static void amd_pmu_wait_on_overflow(int idx) { + struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); + struct hw_perf_event *hwc = &cpuc->events[idx]->hw; unsigned int i; u64 counter; @@ -596,7 +598,7 @@ static void amd_pmu_wait_on_overflow(int idx) * forever... */ for (i = 0; i < OVERFLOW_WAIT_COUNT; i++) { - rdmsrl(x86_pmu_event_addr(idx), counter); + rdpmcl(hwc->event_base_rdpmc, counter); if (counter & (1ULL << (x86_pmu.cntval_bits - 1))) break; -- 2.32.0
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