Date: Fri, 19 May 2006 18:49:54 -0700 From: Julian Elischer <julian@elischer.org> To: David Xu <davidxu@freebsd.org> Cc: freebsd-threads@freebsd.org Subject: Re: optimize msleep with PCATCH flag Message-ID: <446E75C2.4080305@elischer.org> In-Reply-To: <200605200935.54828.davidxu@freebsd.org> References: <200605200935.54828.davidxu@freebsd.org>
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David Xu wrote: >Hi, > >Here is a patch to reduce overhead when PCATCH flag is set >for msleep. >http://people.freebsd.org/~davidxu/patch/PCATCH_optimize.patch > >I use SUN's mutex ping-pong program to test it, source code >is here: http://people.freebsd.org/~davidxu/bench/pp.c > >I have tested it on a dual PIII machine, with command: >./pp -v -s system -n 4 > >Here is the result before and after the patch: > >x plain_PCATCH.txt >+ PCATCH_optimized.txt >+--------------------------------------------------------------------------+ >|+ + + x ++ +* xx x x * x| >| |__________________A__|M___________M_|______________| | >+--------------------------------------------------------------------------+ > N Min Max Median Avg Stddev >x 8 35311 41714 37750.5 38101 1954.5673 >+ 8 32191 39802 36179 35670.125 2401.755 >Difference at 95.0% confidence > -2430.88 +/- 2348.35 > -6.38008% +/- 6.1635% > (Student's t, pooled s = 2189.61) > >David Xu >_______________________________________________ >freebsd-threads@freebsd.org mailing list >http://lists.freebsd.org/mailman/listinfo/freebsd-threads >To unsubscribe, send any mail to "freebsd-threads-unsubscribe@freebsd.org" > > looks like you need to do a lot more samples to get a better error value.. (8 may not be enough)
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