From: Song Liu <songliubraving@fb.com> 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: Song Liu <songliubraving@fb.com> Acked-by: Andi Kleen <andi@firstfloor.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: kernel-team@fb.com Link: http://lore.kernel.org/lkml/20210316211837.910506-3-songliubraving@fb.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> --- tools/perf/builtin-stat.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index 3413e04d989f..097be7578d25 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -920,15 +920,15 @@ 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) { perf_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, ×); if (child_pid != -1) { @@ -949,6 +949,10 @@ 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, ×); } -- 2.34.1