Date: Fri, 28 Oct 2005 13:18:57 -0700 From: John-Mark Gurney <gurney_j@resnet.uoregon.edu> To: Michael VInce <mv@roq.com> Cc: current@freebsd.org Subject: Re: Timers and timing, was: MySQL Performance 6.0rc1 Message-ID: <20051028201857.GQ4115@funkthat.com> In-Reply-To: <43621A8E.1060006@roq.com> References: <30622.1130493370@critter.freebsd.dk> <4361FA1C.1070103@freebsd.org> <4361FDBE.7000500@freebsd.org> <43621A8E.1060006@roq.com>
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Michael VInce wrote this message on Fri, Oct 28, 2005 at 22:33 +1000:
> Hey guys, I been watching this thread and I can confirm that MySQL and
> the Super-smack benchmark greatly rely on this,
> I was able to increase performance %600 by changing
> kern.timecounter.hardware to dummy.
This is probably because dummy doesn't actually do any real
timecounting... and that the times that the benchmark took was longer
then reported by the machine.. dummy just increments a counter, and
means that the times returned only have a relation to how often/much
the time "hardware" was queried...
Use a stopwatch to time the benchmark, and make sure that the time
the benchmark took agrees with what the computer says...
--
John-Mark Gurney Voice: +1 415 225 5579
"All that I will do, has been done, All that I have, has not."
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