Commit-ID:  67266c1080ad56c31af72b9c18355fde8ccc124a
Gitweb:     https://git.kernel.org/tip/67266c1080ad56c31af72b9c18355fde8ccc124a
Author:     Jiri Olsa <jo...@kernel.org>
AuthorDate: Wed, 21 Nov 2018 11:16:11 +0100
Committer:  Ingo Molnar <mi...@kernel.org>
CommitDate: Thu, 22 Nov 2018 09:45:09 +0100

perf/x86/intel: Add generic branch tracing check to intel_pmu_has_bts()

Currently we check the branch tracing only by checking for the
PERF_COUNT_HW_BRANCH_INSTRUCTIONS event of PERF_TYPE_HARDWARE
type. But we can define the same event with the PERF_TYPE_RAW
type.

Changing the intel_pmu_has_bts() code to check on event's final
hw config value, so both HW types are covered.

Adding unlikely to intel_pmu_has_bts() condition calls, because
it was used in the original code in intel_bts_constraints.

Signed-off-by: Jiri Olsa <jo...@kernel.org>
Acked-by: Peter Zijlstra <a.p.zijls...@chello.nl>
Cc: <sta...@vger.kernel.org>
Cc: Alexander Shishkin <alexander.shish...@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <a...@kernel.org>
Cc: Arnaldo Carvalho de Melo <a...@redhat.com>
Cc: Jiri Olsa <jo...@redhat.com>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Stephane Eranian <eran...@google.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Vince Weaver <vincent.wea...@maine.edu>
Link: http://lkml.kernel.org/r/20181121101612.16272-2-jo...@kernel.org
Signed-off-by: Ingo Molnar <mi...@kernel.org>
---
 arch/x86/events/intel/core.c | 17 +++--------------
 arch/x86/events/perf_event.h | 13 +++++++++----
 2 files changed, 12 insertions(+), 18 deletions(-)

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index a95079abeb03..a15a73788693 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -2474,16 +2474,7 @@ done:
 static struct event_constraint *
 intel_bts_constraints(struct perf_event *event)
 {
-       struct hw_perf_event *hwc = &event->hw;
-       unsigned int hw_event, bts_event;
-
-       if (event->attr.freq)
-               return NULL;
-
-       hw_event = hwc->config & INTEL_ARCH_EVENT_MASK;
-       bts_event = x86_pmu.event_map(PERF_COUNT_HW_BRANCH_INSTRUCTIONS);
-
-       if (unlikely(hw_event == bts_event && hwc->sample_period == 1))
+       if (unlikely(intel_pmu_has_bts(event)))
                return &bts_constraint;
 
        return NULL;
@@ -3105,10 +3096,8 @@ static unsigned long intel_pmu_large_pebs_flags(struct 
perf_event *event)
 static int intel_pmu_bts_config(struct perf_event *event)
 {
        struct perf_event_attr *attr = &event->attr;
-       struct hw_perf_event *hwc = &event->hw;
 
-       if (attr->config == PERF_COUNT_HW_BRANCH_INSTRUCTIONS &&
-           !attr->freq && hwc->sample_period == 1) {
+       if (unlikely(intel_pmu_has_bts(event))) {
                /* BTS is not supported by this architecture. */
                if (!x86_pmu.bts_active)
                        return -EOPNOTSUPP;
@@ -3170,7 +3159,7 @@ static int intel_pmu_hw_config(struct perf_event *event)
                /*
                 * BTS is set up earlier in this path, so don't account twice
                 */
-               if (!intel_pmu_has_bts(event)) {
+               if (!unlikely(intel_pmu_has_bts(event))) {
                        /* disallow lbr if conflicting events are present */
                        if (x86_add_exclusive(x86_lbr_exclusive_lbr))
                                return -EBUSY;
diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h
index adae087cecdd..78d7b7031bfc 100644
--- a/arch/x86/events/perf_event.h
+++ b/arch/x86/events/perf_event.h
@@ -859,11 +859,16 @@ static inline int amd_pmu_init(void)
 
 static inline bool intel_pmu_has_bts(struct perf_event *event)
 {
-       if (event->attr.config == PERF_COUNT_HW_BRANCH_INSTRUCTIONS &&
-           !event->attr.freq && event->hw.sample_period == 1)
-               return true;
+       struct hw_perf_event *hwc = &event->hw;
+       unsigned int hw_event, bts_event;
+
+       if (event->attr.freq)
+               return false;
+
+       hw_event = hwc->config & INTEL_ARCH_EVENT_MASK;
+       bts_event = x86_pmu.event_map(PERF_COUNT_HW_BRANCH_INSTRUCTIONS);
 
-       return false;
+       return hw_event == bts_event && hwc->sample_period == 1;
 }
 
 int intel_pmu_save_and_restart(struct perf_event *event);

Reply via email to