Date: Wed, 27 Aug 2003 19:57:18 -0400 (EDT) From: Daniel Eischen <eischen@vigrid.com> To: David Xu <davidxu@FreeBSD.org> Cc: Scott Long <scottl@FreeBSD.org> Subject: Re: Call for thread testers Message-ID: <Pine.GSO.4.10.10308271953550.9892-100000@pcnet5.pcnet.com> In-Reply-To: <200308280723.35697.davidxu@FreeBSD.org>
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On Thu, 28 Aug 2003, David Xu wrote: > On Thursday 28 August 2003 06:07, Daniel Eischen wrote: > > [ redirected to @threads ] > > > David and I have a couple of other tests which we use to > > > measure performance of our threads libraries. > > > > One of these tests is crew, which is part of Dave Butenhof's > > threads tests (http://people.freebsd.org/~davidxu/crew/programs.tar.z) > > > > Usage: crew <string> <directory> > > > > crew searches recursively for the given string in the directory. > > David and I use it as follows: > > > > $ crew node /usr/src/sys > > > > By default, it creates 4 worker threads to seach for the string. > > Here are the results for all thread libraries; they are somewhat > > surprising. The test was run a couple of times to fill up cache > > and those timing results were omitted. > > > > Run 1 Run 2 Run 3 > > ------------------------------------------------------ > > libc_r real 0m48.451s 0m48.835s 0m50.905s > > user 0m2.694s 0m2.745s 0m2.818s > > sys 0m8.996s 0m8.931s 0m8.863s > > ------------------------------------------------------ > > libthr real 1m2.553s 1m52.579s 1m50.306s > > user 0m3.423s 0m4.561s 0m4.397s > > sys 0m11.842s 0m27.099s 0m27.300s > > ------------------------------------------------------ > > libkse(M:N) real 0m49.175s 0m49.910s 0m51.033s > > user 0m2.840s 0m2.836s 0m2.880s > > sys 0m8.857s 0m8.857s 0m8.792s > > ------------------------------------------------------ > > libkse(1:1) real 0m20.240s 0m19.969s 0m19.981s > > user 0m2.741s 0m2.783s 0m2.858s > > sys 0m8.877s 0m8.832s 0m8.768s > > ------------------------------------------------------ > > > > All the above tests were run on a single CPU 850MHz PIII > > with 256MB RAM (Dell Lattitude C400). > > > > There seems to be something wrong with libthr; the times > > vary too much (by almost 100%). libkse in M:N mode seems > > to be on par with libc_r. But the real surprise is libkse > > built in 1:1 mode (add -DSYSTEM_SCOPE_ONLY to CFLAGS when > > building libpthread). > > Er, strange result, libkse M:N and libkse 1:1 should be identical > in this test, I had always run this test, and their performance > are always close enough, but 1:1 was always a bit slow than M:N, > all tests are done under 4BSD scheduler, under ULE scheduler, > SA process has performance problem, M:N is slower under ULE than 1:1. Yes, perhaps my kernel was a bit out of date. I also had forgotten I had libc_r mapped to libkse with libmap.conf, so the libc_r tests were actually using libkse! I re-ran the tests on a different box, single PIII 800MHz, 512MB RAM. They look better, although libthr still doesn't give consistent results. Run 1 Run 2 Run 3 ----------------------------------------------------------- libc_r real 0m13.739s 0m13.739s 0m13.882s user 0m3.330s 0m3.302s 0m3.394s sys 0m9.858s 0m9.893s 0m9.820s ----------------------------------------------------------- libkse(M:N) real 0m11.977s 0m12.199s 0m12.097s user 0m3.248s 0m3.081s 0m2.857s sys 0m8.190s 0m8.517s 0m8.575s ----------------------------------------------------------- libkse(1:1) real 0m11.972s 0m12.044s 0m12.035s user 0m3.198s 0m2.980s 0m3.183s sys 0m8.244s 0m8.480s 0m8.282s ----------------------------------------------------------- libthr real 0m34.180s 0m16.193s 0m34.119s user 0m5.075s 0m3.874s 0m5.255s sys 0m28.286s 0m11.626s 0m28.038s ----------------------------------------------------------- libkse(1:1) and libkse(M:N) are about equal, and slightly better than libc_r. I can't explain libthr results. -- Dan Eischen
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