[PATCH 06/21] perf, stat: FIXME Stddev calculation is incorrect

[Don Zickus]

Fix the standard deviation calculation.  The current calculation
does the standard deviation mean which is slightly different.

Signed-off-by: Don Zickus <dzickus@xxxxxxxxxx>
---
 tools/perf/util/stat.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c
index 6506b3d..58aa661 100644
--- a/tools/perf/util/stat.c
+++ b/tools/perf/util/stat.c
@@ -47,7 +47,8 @@ double stddev_stats(struct stats *stats)
 		return 0.0;
 
 	variance = stats->M2 / (stats->n - 1);
-	variance_mean = variance / stats->n;
+	//variance_mean = variance / stats->n;
+	variance_mean = variance;
 
 	return sqrt(variance_mean);
 }
-- 
1.7.11.7

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