From: Jens Axboe <jens.axboe@oracle.com>
Date: Tue, 6 Mar 2007 14:37:00 +0000 (+0100)
Subject: Stat summation fixup
X-Git-Tag: fio-1.14~79
X-Git-Url: https://git.kernel.dk/?p=fio.git;a=commitdiff_plain;h=c39cced652676a2b1dd76a98ca54f23b1f844cc5

Stat summation fixup

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---

diff --git a/stat.c b/stat.c
index 5470c87f..07c9b62e 100644
--- a/stat.c
+++ b/stat.c
@@ -579,8 +579,8 @@ static void __sum_stat(struct io_stat *dst, struct io_stat *src, int nr)
 		mean = src->mean;
 		S = src->S;
 	} else {
-		mean = ((src->mean * (double) nr) + dst->mean) / ((double) nr + 1.0);
-		S = ((src->S * (double) nr) + dst->S) / ((double) nr + 1.0);
+		mean = ((src->mean * (double) (nr - 1)) + dst->mean) / ((double) nr);
+		S = ((src->S * (double) (nr - 1)) + dst->S) / ((double) nr);
 	}
 
 	dst->mean = mean;