Date: Wed, 28 Jan 2004 15:56:56 -0500 (EST) From: Robert Watson <rwatson@freebsd.org> To: Don Bowman <don@sandvine.com> Cc: "'freebsd-current@freebsd.org'" <freebsd-current@freebsd.org> Subject: Re: system call performance 4.x vs 5.x [and UP vs MP] Message-ID: <Pine.NEB.3.96L.1040128155501.23469M-100000@fledge.watson.org> In-Reply-To: <Pine.NEB.3.96L.1040128130303.47712P-100000@fledge.watson.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Wed, 28 Jan 2004, Robert Watson wrote:
> printf("%d.%09lu for %d iterations\n", ts_end.tv_sec,
> ts_end.tv_nsec, NUM);
> printf("%d.%09lu per/iteration\n", ts_end.tv_sec / NUM,
> ts_end.tv_nsec / NUM);
Having posted this, I should point out that this suffers an error if you
get above a second total measurement time (which I generally don't do to
avoid being preempted). Something like the following would work slightly
better:
ts_end.tv_sec *= 1000000000 / count;
printf("0.%09lu per/iteration\n", ts_end.tv_sec +
ts_end.tv_nsec / count);
Robert N M Watson FreeBSD Core Team, TrustedBSD Projects
robert@fledge.watson.org Senior Research Scientist, McAfee Research
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.NEB.3.96L.1040128155501.23469M-100000>