perf stat: Do not print ratio when task-clock event is not counted
The ratio between the number of events and the time elapsed makes
sense only if task-clock event is counted. Otherwise it will be
simply a (confusing)
# 0.000 M/sec
This patch outputs the ratio only if task-clock event is counted.
Some test examples of before and after:
Before:
[lucas@skywalker linux.trees.git]$ sudo perf stat -e branch-misses -a -- sleep 1
Performance counter stats for 'sleep 1':
1367818 branch-misses # 0.000 M/sec
1.001494325 seconds time elapsed
After (without task-clock):
[lucas@skywalker perf]$ sudo ./perf stat -e branch-misses -a -- sleep 1
Performance counter stats for 'sleep 1':
1135044 branch-misses
1.001370775 seconds time elapsed
After (with task-clock):
[lucas@skywalker perf]$ sudo ./perf stat -e branch-misses -e task-clock -a -- sleep 1
Performance counter stats for 'sleep 1':
1070111 branch-misses # 0.534 M/sec
2002.730893 task-clock-msecs # 1.999 CPUs
1.001640292 seconds time elapsed
Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <20091115140507.GB21561@skywalker.lan>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index c6df377..c70d720 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -357,7 +357,8 @@
ratio = avg / total;
fprintf(stderr, " # %10.3f IPC ", ratio);
- } else if (MATCH_EVENT(HARDWARE, HW_BRANCH_MISSES, counter)) {
+ } else if (MATCH_EVENT(HARDWARE, HW_BRANCH_MISSES, counter) &&
+ runtime_branches_stats.n != 0) {
total = avg_stats(&runtime_branches_stats);
if (total)
@@ -365,7 +366,7 @@
fprintf(stderr, " # %10.3f %% ", ratio);
- } else {
+ } else if (runtime_nsecs_stats.n != 0) {
total = avg_stats(&runtime_nsecs_stats);
if (total)