Commit 435b46ef authored by Song Liu's avatar Song Liu Committed by Arnaldo Carvalho de Melo
Browse files

perf stat: Measure 't0' and 'ref_time' after enable_counters() 



Take measurements of 't0' and 'ref_time' after enable_counters(), so
that they only measure the time consumed when the counters are enabled.

Signed-off-by: default avatarSong Liu <songliubraving@fb.com>
Acked-by: default avatarAndi Kleen <andi@firstfloor.org>
Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Acked-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: kernel-team@fb.com
Link: http://lore.kernel.org/lkml/20210316211837.910506-3-songliubraving@fb.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 7fac83aa

tools/perf/builtin-stat.c

+7 −3
Original line number Diff line number Diff line
@@ -931,15 +931,15 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) 
	/*

	 * Enable counters and exec the command:

	 */

	t0 = rdclock();

	clock_gettime(CLOCK_MONOTONIC, &ref_time);



	if (forks) {

		evlist__start_workload(evsel_list);

		err = enable_counters();

		if (err)

			return -1;



		t0 = rdclock();

		clock_gettime(CLOCK_MONOTONIC, &ref_time);



		if (interval || timeout || evlist__ctlfd_initialized(evsel_list))

			status = dispatch_events(forks, timeout, interval, &times);

		if (child_pid != -1) {
@@ -960,6 +960,10 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) 
		err = enable_counters();

		if (err)

			return -1;



		t0 = rdclock();

		clock_gettime(CLOCK_MONOTONIC, &ref_time);



		status = dispatch_events(forks, timeout, interval, &times);

	}