From a7b58d211ba18c9175b139e18b68c86a6bcc3c3f Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Wed, 27 May 2015 21:13:14 -0700 Subject: [PATCH] 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: Andi Kleen Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner 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: Ingo Molnar --- arch/x86/kernel/cpu/perf_event.h | 1 + arch/x86/kernel/cpu/perf_event_intel.c | 15 ++++++++++++++- arch/x86/kernel/cpu/perf_event_intel_ds.c | 1 + 3 files changed, 16 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/perf_event.h b/arch/x86/kernel/cpu/perf_event.h index 3474cf2..7378b10 100644 --- a/arch/x86/kernel/cpu/perf_event.h +++ b/arch/x86/kernel/cpu/perf_event.h @@ -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 diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c index 71815cf..cb112bf 100644 --- a/arch/x86/kernel/cpu/perf_event_intel.c +++ b/arch/x86/kernel/cpu/perf_event_intel.c @@ -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 diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c index 410270a..03773c2 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_ds.c +++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c @@ -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: -- 2.7.4