Date: Wed, 11 Oct 2023 18:01:02 GMT From: Mark Johnston <markj@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 4d348e83b738 - main - ping: Avoid reporting NaNs Message-ID: <202310111801.39BI12KA053616@gitrepo.freebsd.org>
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The branch main has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=4d348e83b738347f6aaf2b110459a01c5402d04e commit 4d348e83b738347f6aaf2b110459a01c5402d04e Author: Jose Luis Duran <jlduran@gmail.com> AuthorDate: 2023-10-06 17:55:06 +0000 Commit: Mark Johnston <markj@FreeBSD.org> CommitDate: 2023-10-11 17:48:27 +0000 ping: Avoid reporting NaNs Avoid calculating the square root of negative zero, which can easily happen on certain architectures when calculating the population standard deviation with a sample size of one, e.g., 0.01 - (0.1 * 0.1) = -0.000000. Avoid returning a NaN by capping the minimum possible variance value to zero (positive). In the future, maybe skip reporting statistics at all for a single sample. Reported by: Jenkins Reviewed by: asomers MFC after: 1 week Pull Request: https://github.com/freebsd/freebsd-src/pull/863 Differential Revision: https://reviews.freebsd.org/D42114 --- sbin/ping/ping.c | 4 ++-- sbin/ping/ping6.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/sbin/ping/ping.c b/sbin/ping/ping.c index 072d4607f745..f67d85f30a5d 100644 --- a/sbin/ping/ping.c +++ b/sbin/ping/ping.c @@ -1522,10 +1522,10 @@ finish(void) if (nreceived && timing) { double n = nreceived + nrepeats; double avg = tsum / n; - double vari = tsumsq / n - avg * avg; + double stddev = sqrt(fmax(0, tsumsq / n - avg * avg)); (void)printf( "round-trip min/avg/max/stddev = %.3f/%.3f/%.3f/%.3f ms\n", - tmin, avg, tmax, sqrt(vari)); + tmin, avg, tmax, stddev); } if (nreceived) diff --git a/sbin/ping/ping6.c b/sbin/ping/ping6.c index bd1658f9500a..d14da9c67a52 100644 --- a/sbin/ping/ping6.c +++ b/sbin/ping/ping6.c @@ -2349,10 +2349,10 @@ summary(void) /* Only display average to microseconds */ double num = nreceived + nrepeats; double avg = tsum / num; - double dev = sqrt(tsumsq / num - avg * avg); + double stddev = sqrt(fmax(0, tsumsq / num - avg * avg)); (void)printf( "round-trip min/avg/max/std-dev = %.3f/%.3f/%.3f/%.3f ms\n", - tmin, avg, tmax, dev); + tmin, avg, tmax, stddev); (void)fflush(stdout); } (void)fflush(stdout);
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