From f99844cb76b7d347711c22cdcb94266b7214141f Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Wed, 27 Apr 2011 05:35:39 +0200 Subject: [PATCH] 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 Acked-by: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker Link: http://lkml.kernel.org/n/tip-z89h2v1bk1mikcbsf7e6v34q@git.kernel.org Signed-off-by: Ingo Molnar --- tools/perf/builtin-stat.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index 924d18c..845ded8 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -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"); } -- 2.7.4