From 2a853e1123cbbb43ff74cc47b4ec582ce34df262 Mon Sep 17 00:00:00 2001 From: "Liang, Kan" Date: Fri, 3 Jul 2015 20:08:27 +0000 Subject: [PATCH] perf/x86/intel/pebs: Fix event disable PEBS buffer drain When disabling a PEBS event, we need to drain the buffer. Doing so requires a correct cpuc->pebs_active mask. The current code clears the pebs_active bit before draining the buffer. Fix that. Signed-off-by: "Liang, Kan" Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Vince Weaver Link: http://lkml.kernel.org/r/37D7C6CF3E00A74B8858931C1DB2F07701885A65@SHSMSX103.ccr.corp.intel.com [ Fixed the SOB. ] Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_event_intel_ds.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c index 2f7ee0541a8f..8e564f817a7f 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_ds.c +++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c @@ -789,6 +789,11 @@ void intel_pmu_pebs_disable(struct perf_event *event) struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); struct hw_perf_event *hwc = &event->hw; struct debug_store *ds = cpuc->ds; + bool large_pebs = ds->pebs_interrupt_threshold > + ds->pebs_buffer_base + x86_pmu.pebs_record_size; + + if (large_pebs) + intel_pmu_drain_pebs_buffer(); cpuc->pebs_enabled &= ~(1ULL << hwc->idx); @@ -797,12 +802,8 @@ void intel_pmu_pebs_disable(struct perf_event *event) else if (event->hw.flags & PERF_X86_EVENT_PEBS_ST) cpuc->pebs_enabled &= ~(1ULL << 63); - if (ds->pebs_interrupt_threshold > - ds->pebs_buffer_base + x86_pmu.pebs_record_size) { - intel_pmu_drain_pebs_buffer(); - if (!pebs_is_enabled(cpuc)) - perf_sched_cb_dec(event->ctx->pmu); - } + if (large_pebs && !pebs_is_enabled(cpuc)) + perf_sched_cb_dec(event->ctx->pmu); if (cpuc->enabled) wrmsrl(MSR_IA32_PEBS_ENABLE, cpuc->pebs_enabled);