Commit-ID: 5bee2cc69d986e20808c93c46f7b6aef51edd827 Gitweb: https://git.kernel.org/tip/5bee2cc69d986e20808c93c46f7b6aef51edd827 Author: Kan Liang <kan.li...@linux.intel.com> AuthorDate: Mon, 12 Feb 2018 14:20:33 -0800 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Fri, 9 Mar 2018 08:22:21 +0100
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.li...@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Cc: Alexander Shishkin <alexander.shish...@linux.intel.com> 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> Cc: a...@kernel.org Link: http://lkml.kernel.org/r/1518474035-21006-4-git-send-email-kan.li...@linux.intel.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/events/intel/ds.c | 9 +++++++++ arch/x86/events/perf_event.h | 2 ++ 2 files changed, 11 insertions(+) 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);
