diff options
| author | Namhyung Kim <namhyung@kernel.org> | 2016-05-13 08:01:03 +0200 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2016-05-17 04:11:47 +0200 |
| commit | a1f3d56761df31f0ffeb215b974e26d5613e92a4 (patch) | |
| tree | 8afe5781fc1229fdfd6f1d4f78ddfdfb70c76231 | |
| parent | perf stat: Update runtime using cpu-clock event (diff) | |
| download | linux-a1f3d56761df31f0ffeb215b974e26d5613e92a4.tar.xz linux-a1f3d56761df31f0ffeb215b974e26d5613e92a4.zip | |
perf stat: Use cpu-clock event for cpu targets
Currently 'perf stat' always counts task-clock event by default. But
it's somewhat confusing for system-wide targets (especially with 'sleep
N' as the 'sleep' task just sleeps and doesn't use cputime). Changing
to cpu-clock event instead for that case makes more sense IMHO.
Before:
# perf stat -a sleep 0.1
Performance counter stats for 'system wide':
403.038603 task-clock (msec) # 4.001 CPUs utilized
150 context-switches # 0.372 K/sec
7 cpu-migrations # 0.017 K/sec
71 page-faults # 0.176 K/sec
23,705,169 cycles # 0.059 GHz
15,888,166 instructions # 0.67 insn per cycle
3,326,078 branches # 8.253 M/sec
87,643 branch-misses # 2.64% of all branches
0.100737009 seconds time elapsed
#
After:
# perf stat -a sleep 0.1
Performance counter stats for 'system wide':
404.271182 cpu-clock (msec) # 4.000 CPUs utilized
143 context-switches # 0.354 K/sec
13 cpu-migrations # 0.032 K/sec
73 page-faults # 0.181 K/sec
22,119,220 cycles # 0.055 GHz
13,622,065 instructions # 0.62 insn per cycle
2,918,769 branches # 7.220 M/sec
85,033 branch-misses # 2.91% of all branches
0.101073089 seconds time elapsed
#
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1463119263-5569-3-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| -rw-r--r-- | tools/perf/builtin-stat.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index 16a923c1633b..efdd23221c16 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -1905,6 +1905,9 @@ static int add_default_attributes(void) } if (!evsel_list->nr_entries) { + if (target__has_cpu(&target)) + default_attrs0[0].config = PERF_COUNT_SW_CPU_CLOCK; + if (perf_evlist__add_default_attrs(evsel_list, default_attrs0) < 0) return -1; if (pmu_have_event("cpu", "stalled-cycles-frontend")) { |