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Commit a7b58d21 authored by Andi Kleen's avatar Andi Kleen Committed by Ingo Molnar
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perf/x86/intel/lbr: Allow time stamp for free running PEBSv3 



With PEBSv3 the PEBS record contains a time stamp. That means we can allow
free-running PEBS without a PMI even if the user program requested a time stamp.
This avoids the need to use -T to get free running PEBS, and also avoids
any problems with mis-identifying MMAPs later.

Move the free_running_flags state into a variable in x86_pmu and use it.
This only works when no explicit clock_id is set.

Signed-off-by: default avatarAndi Kleen <ak@linux.intel.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@kernel.org
Cc: eranian@google.com
Cc: jolsa@redhat.com
Cc: kan.liang@intel.com
Link: http://lkml.kernel.org/r/1432786398-23861-2-git-send-email-andi@firstfloor.org


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 2f7ebf2e

arch/x86/kernel/cpu/perf_event.h

+1 −0
Original line number Diff line number Diff line
@@ -594,6 +594,7 @@ struct x86_pmu { 
	struct event_constraint *pebs_constraints;

	void		(*pebs_aliases)(struct perf_event *event);

	int 		max_pebs_events;

	unsigned long	free_running_flags;



	/*

	 * Intel LBR

arch/x86/kernel/cpu/perf_event_intel.c

+14 −1
Original line number Diff line number Diff line
@@ -2257,6 +2257,15 @@ static void intel_pebs_aliases_snb(struct perf_event *event) 
	}

}



static unsigned long intel_pmu_free_running_flags(struct perf_event *event)

{

	unsigned long flags = x86_pmu.free_running_flags;



	if (event->attr.use_clockid)

		flags &= ~PERF_SAMPLE_TIME;

	return flags;

}



static int intel_pmu_hw_config(struct perf_event *event)

{

	int ret = x86_pmu_hw_config(event);
@@ -2267,7 +2276,8 @@ static int intel_pmu_hw_config(struct perf_event *event) 
	if (event->attr.precise_ip) {

		if (!event->attr.freq) {

			event->hw.flags |= PERF_X86_EVENT_AUTO_RELOAD;

			if (!(event->attr.sample_type & ~PEBS_FREERUNNING_FLAGS))

			if (!(event->attr.sample_type &

			      ~intel_pmu_free_running_flags(event)))

				event->hw.flags |= PERF_X86_EVENT_FREERUNNING;

		}

		if (x86_pmu.pebs_aliases)
@@ -2689,6 +2699,8 @@ static __initconst const struct x86_pmu core_pmu = { 
	.event_map		= intel_pmu_event_map,

	.max_events		= ARRAY_SIZE(intel_perfmon_event_map),

	.apic			= 1,

	.free_running_flags	= PEBS_FREERUNNING_FLAGS,



	/*

	 * Intel PMCs cannot be accessed sanely above 32-bit width,

	 * so we install an artificial 1<<31 period regardless of
@@ -2727,6 +2739,7 @@ static __initconst const struct x86_pmu intel_pmu = { 
	.event_map		= intel_pmu_event_map,

	.max_events		= ARRAY_SIZE(intel_perfmon_event_map),

	.apic			= 1,

	.free_running_flags	= PEBS_FREERUNNING_FLAGS,

	/*

	 * Intel PMCs cannot be accessed sanely above 32 bit width,

	 * so we install an artificial 1<<31 period regardless of

arch/x86/kernel/cpu/perf_event_intel_ds.c

+1 −0
Original line number Diff line number Diff line
@@ -1273,6 +1273,7 @@ void __init intel_ds_init(void) 
			x86_pmu.pebs_record_size =

						sizeof(struct pebs_record_skl);

			x86_pmu.drain_pebs = intel_pmu_drain_pebs_nhm;

			x86_pmu.free_running_flags |= PERF_SAMPLE_TIME;

			break;



		default: