Commit-ID: 45528f7c699a71d2f3096173980aadd43dff6eaa Gitweb: http://git.kernel.org/tip/45528f7c699a71d2f3096173980aadd43dff6eaa Author: David Ahern <dsahern@xxxxxxxxx> AuthorDate: Sat, 25 May 2013 18:24:48 -0600 Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> CommitDate: Tue, 28 May 2013 16:24:04 +0300 perf stats: Fix divide by 0 in variance Number of samples needs to be greater 1 to have a variance. Fixes nan% in perf-kvm-live output. Signed-off-by: David Ahern <dsahern@xxxxxxxxx> Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Namhyung Kim <namhyung@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Runzhen Wang <runzhen@xxxxxxxxxxxxxxxxxx> Cc: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/1369527896-3650-9-git-send-email-dsahern@xxxxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> --- tools/perf/util/stat.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c index 2374212..7c59c28 100644 --- a/tools/perf/util/stat.c +++ b/tools/perf/util/stat.c @@ -37,7 +37,7 @@ double stddev_stats(struct stats *stats) { double variance, variance_mean; - if (!stats->n) + if (stats->n < 2) return 0.0; variance = stats->M2 / (stats->n - 1); -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html