From c3feedf2aaf9ac8bad6f19f5d21e4ee0b4b87e9c Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Thu, 24 Jan 2013 16:10:28 +0100 Subject: perf/core: Add weighted samples For some events it's useful to weight sample with a hardware provided number. This expresses how expensive the action the sample represent was. This allows the profiler to scale the samples to be more informative to the programmer. There is already the period which is used similarly, but it means something different, so I chose to not overload it. Instead a new sample type for WEIGHT is added. Can be used for multiple things. Initially it is used for TSX abort costs and profiling by memory latencies (so to make expensive load appear higher up in the histograms). The concept is quite generic and can be extended to many other kinds of events or architectures, as long as the hardware provides suitable auxillary values. In principle it could be also used for software tracepoints. This adds the generic glue. A new optional sample format for a 64-bit weight value. Signed-off-by: Andi Kleen Signed-off-by: Stephane Eranian Cc: peterz@infradead.org Cc: acme@redhat.com Cc: jolsa@redhat.com Cc: namhyung.kim@lge.com Link: http://lkml.kernel.org/r/1359040242-8269-5-git-send-email-eranian@google.com Signed-off-by: Ingo Molnar Signed-off-by: Arnaldo Carvalho de Melo --- kernel/events/core.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'kernel/events') diff --git a/kernel/events/core.c b/kernel/events/core.c index 7b4a55d41efc..9e3edb272b3e 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -976,6 +976,9 @@ static void perf_event__header_size(struct perf_event *event) if (sample_type & PERF_SAMPLE_PERIOD) size += sizeof(data->period); + if (sample_type & PERF_SAMPLE_WEIGHT) + size += sizeof(data->weight); + if (sample_type & PERF_SAMPLE_READ) size += event->read_size; @@ -4193,6 +4196,9 @@ void perf_output_sample(struct perf_output_handle *handle, perf_output_sample_ustack(handle, data->stack_user_size, data->regs_user.regs); + + if (sample_type & PERF_SAMPLE_WEIGHT) + perf_output_put(handle, data->weight); } void perf_prepare_sample(struct perf_event_header *header, -- cgit v1.2.3