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 <ak@linux.intel.com>
Signed-off-by: Peter 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: Ingo Molnar <mingo@kernel.org>

1 files changed, 14 insertions, 1 deletions

diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index 71815cf3d2d3..cb112bffcf70 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