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authorKan Liang <kan.liang@linux.intel.com>2018-02-12 14:20:33 -0800
committerIngo Molnar <mingo@kernel.org>2018-03-09 08:22:21 +0100
commit5bee2cc69d986e20808c93c46f7b6aef51edd827 (patch)
tree0cbd8142873fce0940eb2f82cfb9d8627f1bcc8c /arch
parentbcfbe5c41d630ce6b74da45134cea484248b515a (diff)
perf/x86/intel/ds: Introduce ->read() function for auto-reload events and flush the PEBS buffer there
There is no way to get exact auto-reload times and values which are needed for event updates unless we flush the PEBS buffer. Introduce intel_pmu_auto_reload_read() to drain the PEBS buffer for auto reload event. To prevent races with the hardware, we can only call drain_pebs() when the PMU is disabled. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: acme@kernel.org Link: http://lkml.kernel.org/r/1518474035-21006-4-git-send-email-kan.liang@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/events/intel/ds.c9
-rw-r--r--arch/x86/events/perf_event.h2
2 files changed, 11 insertions, 0 deletions
diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index f39a4df3a7bd..73844025adaf 100644
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -1306,6 +1306,15 @@ get_next_pebs_record_by_bit(void *base, void *top, int bit)
return NULL;
}
+void intel_pmu_auto_reload_read(struct perf_event *event)
+{
+ WARN_ON(!(event->hw.flags & PERF_X86_EVENT_AUTO_RELOAD));
+
+ perf_pmu_disable(event->pmu);
+ intel_pmu_drain_pebs_buffer();
+ perf_pmu_enable(event->pmu);
+}
+
/*
* Special variant of intel_pmu_save_and_restart() for auto-reload.
*/
diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h
index d445f0026989..91643472f385 100644
--- a/arch/x86/events/perf_event.h
+++ b/arch/x86/events/perf_event.h
@@ -924,6 +924,8 @@ void intel_pmu_pebs_disable_all(void);
void intel_pmu_pebs_sched_task(struct perf_event_context *ctx, bool sched_in);
+void intel_pmu_auto_reload_read(struct perf_event *event);
+
void intel_ds_init(void);
void intel_pmu_lbr_sched_task(struct perf_event_context *ctx, bool sched_in);