Messages in this thread |  | | | Subject | Re: [PATCH 1/2] pebs, x86: Make sure to really disable PEBS | | From | Peter Zijlstra <> | | Date | Mon, 20 Aug 2012 12:10:00 +0200 |
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On Sat, 2012-08-18 at 09:15 -0700, Andi Kleen wrote: > From: Andi Kleen <ak@linux.intel.com> > > When disabling a PEBS event we need to check the old value > to determine if PEBS was running. Otherwise the last PEBS value > could be kept running. > > Signed-off-by: Andi Kleen <ak@linux.intel.com> > --- > arch/x86/kernel/cpu/perf_event_intel_ds.c | 3 ++- > 1 files changed, 2 insertions(+), 1 deletions(-) > > diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c > index e38d97b..db49ab3 100644 > --- a/arch/x86/kernel/cpu/perf_event_intel_ds.c > +++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c > @@ -438,9 +438,10 @@ void intel_pmu_pebs_disable(struct perf_event *event) > { > struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); > struct hw_perf_event *hwc = &event->hw; > + u64 old = cpuc->pebs_enabled; > > cpuc->pebs_enabled &= ~(1ULL << hwc->idx); > - if (cpuc->enabled) > + if (old)
cpuc->enabled != cpuc->pebs_enabled
> wrmsrl(MSR_IA32_PEBS_ENABLE, cpuc->pebs_enabled); > > hwc->config |= ARCH_PERFMON_EVENTSEL_INT;
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