pebs, x86: Make sure to really disable PEBS
Subsystems (2)
PATCH 1/2 pebs, x86: Make sure to really disable PEBS
From: Andi Kleen <[email protected]>
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.
--- arch/x86/kernel/cpu/perf_event_intel_ds.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-)
arch/x86/kernel/cpu/perf_event_intel_ds.c +2 -1
@@ -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 ;
Signature · 1 line
1.7.7.6
PATCH 2/2 perf: Enable function tracing for perf core
From: Andi Kleen <[email protected]>
According to Steven R. there is no reason left to not support function tracing for the perf core. This makes it easier to debug perf.
Don't remove -pg for the x86 and generic perf core.
--- arch/x86/kernel/cpu/Makefile | 1 - kernel/events/Makefile | 4 ---- 2 files changed, 0 insertions(+), 5 deletions(-)
arch/x86/kernel/cpu/Makefile +0 -1
@@ -5,7 +5,6 @@ # Don't trace early stages of a secondary CPU boot ifdef CONFIG_FUNCTION_TRACER CFLAGS_REMOVE_common.o = -pg -CFLAGS_REMOVE_perf_event.o = -pg endif # Make sure load_percpu_segment has no stackprotector
kernel/events/Makefile +0 -4
@@ -1,7 +1,3 @@ -ifdef CONFIG_FUNCTION_TRACER -CFLAGS_REMOVE_core.o = -pg -endif - obj-y := core.o ring_buffer.o callchain.o obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
Signature · 1 line
1.7.7.6
Re: [PATCH 2/2] perf: Enable function tracing for perf core
Quoted 7 lines · Andi Kleen
From: Andi Kleen <[email protected]>
According to Steven R. there is no reason left to not support function tracing for the perf core. This makes it easier to debug perf.
Don't remove -pg for the x86 and generic perf core.
There's some new patches queued for 3.7 that has better function tracing recursion protection. This should go after those.
Thanks,
-- Steve
Quoted 16 lines · Andi Kleen
From: Andi Kleen <[email protected]>
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 <[email protected]>--- arch/x86/kernel/cpu/perf_event_intel_ds.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-)arch/x86/kernel/cpu/perf_event_intel_ds.c +0
-0
arch/x86/kernel/cpu/perf_event_intel_ds.c void intel_pmu_pebs_disable(struct perf_event *event) · line 444
Quoted 8 lines
arch/x86/kernel/cpu/perf_event_intel_ds.c +2
-1@@ -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
Quoted 3 lines
arch/x86/kernel/cpu/perf_event_intel_ds.c +0
-0wrmsrl (MSR_IA32_PEBS_ENABLE , cpuc->pebs_enabled); hwc->config |=ARCH_PERFMON_EVENTSEL_INT ;