From c3feedf2aaf9ac8bad6f19f5d21e4ee0b4b87e9c Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Thu, 24 Jan 2013 16:10:28 +0100 Subject: [PATCH] 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 --- include/linux/perf_event.h | 2 ++ include/uapi/linux/perf_event.h | 6 +++++- kernel/events/core.c | 6 ++++++ 3 files changed, 13 insertions(+), 1 deletion(-) diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index cd3bb2cd9494..7ce0b37b155b 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -573,6 +573,7 @@ struct perf_sample_data { struct perf_branch_stack *br_stack; struct perf_regs_user regs_user; u64 stack_user_size; + u64 weight; }; static inline void perf_sample_data_init(struct perf_sample_data *data, @@ -586,6 +587,7 @@ static inline void perf_sample_data_init(struct perf_sample_data *data, data->regs_user.abi = PERF_SAMPLE_REGS_ABI_NONE; data->regs_user.regs = NULL; data->stack_user_size = 0; + data->weight = 0; } extern void perf_output_sample(struct perf_output_handle *handle, diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h index 9fa9c622a7f4..cdc255da02e2 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -132,8 +132,10 @@ enum perf_event_sample_format { PERF_SAMPLE_BRANCH_STACK = 1U << 11, PERF_SAMPLE_REGS_USER = 1U << 12, PERF_SAMPLE_STACK_USER = 1U << 13, + PERF_SAMPLE_WEIGHT = 1U << 14, + + PERF_SAMPLE_MAX = 1U << 15, /* non-ABI */ - PERF_SAMPLE_MAX = 1U << 14, /* non-ABI */ }; /* @@ -588,6 +590,8 @@ enum perf_event_type { * { u64 size; * char data[size]; * u64 dyn_size; } && PERF_SAMPLE_STACK_USER + * + * { u64 weight; } && PERF_SAMPLE_WEIGHT * }; */ PERF_RECORD_SAMPLE = 9, 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,