From: Andi Kleen <a...@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 <a...@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)
wrmsrl(MSR_IA32_PEBS_ENABLE, cpuc->pebs_enabled);
hwc->config |= ARCH_PERFMON_EVENTSEL_INT;
--
1.7.7.6
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