perf stat: Fix -nan% output in perf stat noise printouts

Before:

                 0 CPU-migrations           #    0.000 M/sec                    ( +-  -nan% )

After:

                 0 CPU-migrations           #    0.000 M/sec                    ( +-  0.00% )

Also factor out the noise printing function.

Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/n/tip-z89h2v1bk1mikcbsf7e6v34q@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Ingo Molnar 2011-04-27 05:35:39 +02:00
parent 1fc570ad89
commit f99844cb76

View File

@ -382,6 +382,16 @@ static int run_perf_stat(int argc __used, const char **argv)
return WEXITSTATUS(status);
}
static void print_noise_pct(double total, double avg)
{
double pct = 0.0;
if (avg)
pct = 100.0*total/avg;
fprintf(stderr, " ( +-%6.2f%% )", pct);
}
static void print_noise(struct perf_evsel *evsel, double avg)
{
struct perf_stat *ps;
@ -390,8 +400,7 @@ static void print_noise(struct perf_evsel *evsel, double avg)
return;
ps = evsel->priv;
fprintf(stderr, " ( +- %7.3f%% )",
100 * stddev_stats(&ps->res_stats[0]) / avg);
print_noise_pct(stddev_stats(&ps->res_stats[0]), avg);
}
static void nsec_printout(int cpu, struct perf_evsel *evsel, double avg)
@ -635,9 +644,8 @@ static void print_stat(int argc, const char **argv)
fprintf(stderr, " %18.9f seconds time elapsed",
avg_stats(&walltime_nsecs_stats)/1e9);
if (run_count > 1) {
fprintf(stderr, " ( +-%5.2f%% )",
100*stddev_stats(&walltime_nsecs_stats) /
avg_stats(&walltime_nsecs_stats));
print_noise_pct(stddev_stats(&walltime_nsecs_stats),
avg_stats(&walltime_nsecs_stats));
}
fprintf(stderr, "\n\n");
}