From 538d9c1829eddf375436c52604f82ff3f53c6690 Mon Sep 17 00:00:00 2001 From: Stephen Brennan Date: Wed, 1 Sep 2021 14:08:15 -0700 Subject: perf script python: Allow reporting the [un]throttle PERF_RECORD_ meta event perf_events may sometimes throttle an event due to creating too many samples during a given timer tick. As of now, the perf tool will not report on throttling, which means this is a silent error. Implement a callback for the throttle and unthrottle events within the Python scripting engine, which can allow scripts to detect and report when events may have been lost due to throttling. The simplest script to report throttle events is: def throttle(*args): print("throttle" + repr(args)) def unthrottle(*args): print("unthrottle" + repr(args)) Signed-off-by: Stephen Brennan Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/20210901210815.133251-1-stephen.s.brennan@oracle.com Signed-off-by: Arnaldo Carvalho de Melo --- .../util/scripting-engines/trace-event-python.c | 32 ++++++++++++++++++++++ 1 file changed, 32 insertions(+) (limited to 'tools/perf/util/scripting-engines/trace-event-python.c') diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c index 69129e2aa7a1..c0c010350bc2 100644 --- a/tools/perf/util/scripting-engines/trace-event-python.c +++ b/tools/perf/util/scripting-engines/trace-event-python.c @@ -1422,6 +1422,37 @@ static void python_process_event(union perf_event *event, } } +static void python_process_throttle(union perf_event *event, + struct perf_sample *sample, + struct machine *machine) +{ + const char *handler_name; + PyObject *handler, *t; + + if (event->header.type == PERF_RECORD_THROTTLE) + handler_name = "throttle"; + else + handler_name = "unthrottle"; + handler = get_handler(handler_name); + if (!handler) + return; + + t = tuple_new(6); + if (!t) + return; + + tuple_set_u64(t, 0, event->throttle.time); + tuple_set_u64(t, 1, event->throttle.id); + tuple_set_u64(t, 2, event->throttle.stream_id); + tuple_set_s32(t, 3, sample->cpu); + tuple_set_s32(t, 4, sample->pid); + tuple_set_s32(t, 5, sample->tid); + + call_object(handler, t, handler_name); + + Py_DECREF(t); +} + static void python_do_process_switch(union perf_event *event, struct perf_sample *sample, struct machine *machine) @@ -2079,5 +2110,6 @@ struct scripting_ops python_scripting_ops = { .process_auxtrace_error = python_process_auxtrace_error, .process_stat = python_process_stat, .process_stat_interval = python_process_stat_interval, + .process_throttle = python_process_throttle, .generate_script = python_generate_script, }; -- cgit