From: Chunxin Zang <zangchunxin@lixiang.com>
Date: Tue, 28 Mar 2023 06:00:57 +0000 (+0800)
Subject: perf sched: Fix sched latency analysis incorrection when using 'sched:sched_wakeup'
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=4453deacf44615b2d45a0b5226ff132e830bd03d;p=linux.git

perf sched: Fix sched latency analysis incorrection when using 'sched:sched_wakeup'

'perf sched latency' is incorrect to get process schedule latency when
it used 'sched:sched_wakeup' to analysis perf.data.

Because 'perf record' prefers to use 'sched:sched_waking' to
'sched:sched_wakeup' since commit d566a9c2d482 ("perf sched: Prefer
sched_waking event when it exists"). It's very reasonable to evaluate
process schedule latency.

Similarly, update sched latency/map/replay to use sched_waking events.

Signed-off-by: Chunxin Zang <zangchunxin@lixiang.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230328060038.2346935-1-zangchunxin@lixiang.com
Signed-off-by: Jerry Zhou <zhouchunhua@lixiang.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---

diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index 96a0dceadeffd..cc4ba506e1196 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -1516,6 +1516,14 @@ static int process_sched_wakeup_event(struct perf_tool *tool,
 	return 0;
 }
 
+static int process_sched_wakeup_ignore(struct perf_tool *tool __maybe_unused,
+				      struct evsel *evsel __maybe_unused,
+				      struct perf_sample *sample __maybe_unused,
+				      struct machine *machine __maybe_unused)
+{
+	return 0;
+}
+
 union map_priv {
 	void	*ptr;
 	bool	 color;
@@ -1816,10 +1824,11 @@ static int perf_sched__process_comm(struct perf_tool *tool __maybe_unused,
 
 static int perf_sched__read_events(struct perf_sched *sched)
 {
-	const struct evsel_str_handler handlers[] = {
+	struct evsel_str_handler handlers[] = {
 		{ "sched:sched_switch",	      process_sched_switch_event, },
 		{ "sched:sched_stat_runtime", process_sched_runtime_event, },
 		{ "sched:sched_wakeup",	      process_sched_wakeup_event, },
+		{ "sched:sched_waking",	      process_sched_wakeup_event, },
 		{ "sched:sched_wakeup_new",   process_sched_wakeup_event, },
 		{ "sched:sched_migrate_task", process_sched_migrate_task_event, },
 	};
@@ -1839,6 +1848,10 @@ static int perf_sched__read_events(struct perf_sched *sched)
 
 	symbol__init(&session->header.env);
 
+	/* prefer sched_waking if it is captured */
+	if (evlist__find_tracepoint_by_name(session->evlist, "sched:sched_waking"))
+		handlers[2].handler = process_sched_wakeup_ignore;
+
 	if (perf_session__set_tracepoints_handlers(session, handlers))
 		goto out_delete;