From 2cb5383b30d47c446ec7d884cd80f93ffcc31817 Mon Sep 17 00:00:00 2001 From: Kan Liang Date: Thu, 23 Jul 2020 10:11:14 -0700 Subject: perf/x86/intel: Support per-thread RDPMC TopDown metrics Starts from Ice Lake, the TopDown metrics are directly available as fixed counters and do not require generic counters. Also, the TopDown metrics can be collected per thread. Extend the RDPMC usage to support per-thread TopDown metrics. The RDPMC index of the PERF_METRICS will be output if RDPMC users ask for the RDPMC index of the metrics events. To support per thread RDPMC TopDown, the metrics and slots counters have to be saved/restored during the context switching. The last_period and period_left are not used in the counting mode. Use the fields for saved_metric and saved_slots. Signed-off-by: Kan Liang Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20200723171117.9918-12-kan.liang@linux.intel.com --- include/linux/perf_event.h | 29 +++++++++++++++++++---------- 1 file changed, 19 insertions(+), 10 deletions(-) (limited to 'include') diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 6048650f8c1d..46a3974eb4fe 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -212,17 +212,26 @@ struct hw_perf_event { */ u64 sample_period; - /* - * The period we started this sample with. - */ - u64 last_period; + union { + struct { /* Sampling */ + /* + * The period we started this sample with. + */ + u64 last_period; - /* - * However much is left of the current period; note that this is - * a full 64bit value and allows for generation of periods longer - * than hardware might allow. - */ - local64_t period_left; + /* + * However much is left of the current period; + * note that this is a full 64bit value and + * allows for generation of periods longer + * than hardware might allow. + */ + local64_t period_left; + }; + struct { /* Topdown events counting for context switch */ + u64 saved_metric; + u64 saved_slots; + }; + }; /* * State for throttling the event, see __perf_event_overflow() and -- cgit v1.2.3