Date: Fri, 21 Dec 2007 11:46:34 +0200 From: Krassimir Slavchev <krassi@bulinfo.net> To: Claus Guttesen <kometen@gmail.com> Cc: FreeBSD <freebsd-stable@freebsd.org> Subject: Re: Performance! Message-ID: <476B8B7A.1020008@bulinfo.net> In-Reply-To: <b41c75520712200635q72b3246ch60cfe00a9eb641a7@mail.gmail.com> References: <476A5EE1.9000003@bulinfo.net> <b41c75520712200635q72b3246ch60cfe00a9eb641a7@mail.gmail.com>
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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Claus Guttesen wrote: >> I have read all related threads about performance problems with multi >> core systems but still have no idea what to do to make thinks better. >> Below are results of testing postgresql on HP DL380G5 using sysbench. >> The results are comparable to: >> http://blog.insidesystems.net/articles/2007/04/11/postgresql-scaling-on-6-2-and-7-0 >> but the same tests running on the same hardware using Linux (kernel >> 2.6.18-53.1.4.el5 SMP x86_64) are very different. >> PostgreSQL is tuned equal. >> >> results: >> FreeBSD 7.0-BETA4 amd64 (cvsup on 20.12) GENERIC with SCHED_ULE >> #threads #transactions/sec user/system >> 1 500 7.4%,5.3% >> 5 1990 30.9%,23.4% >> 10 2510 39.9%,35.0% >> 20 2549 44.5%,43.5% >> 40 1921 29.8%,59.4% >> 60 1580 22.7%,70.6% >> 80 1341 18.9%,75.9% >> 100 1227 16.5%,79.3% >> >> Linux >> #threads #transactions/sec >> 1 693 >> 5 3539 >> 10 5789 >> 20 5791 >> 40 5661 >> 60 5517 >> 80 5401 >> 100 5319 >> >> What can be done to improve these results? > > What postgres-version did you use for this benchmark? Eventhough this > is a synthetic benchmark the difference in performance may indicate > some penalties on 8-core servers on FreeBSD. 8.2.5 from ports > > According to http://people.freebsd.org/~kris/scaling/mysql.html mysql > scale the same until until 8 clients on both Linux and FreeBSD. This > is an older test though and Linux has probably done some > optimizations. > > Could be interesting so see whether the results differ if you disable > one of the cpu's and rerun the tests. > 2 cores: #threads #transactions/sec user/system 1 541 27.8%,19.0% 5 1068 57.1%,28.4% 40 1086 55.2%,32.1% 100 997 57.5%,28.9% 4 cores: #threads #transactions/sec user/system 1 512 12.3%,8.8% 5 1531 50.3%,31.5% 10 1651 51.6%,33.7% 40 1490 47.3%,37.8% 60 1320 44.0%,44.8% 100 1117 37.5%,51.8% -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (FreeBSD) iD8DBQFHa4t6xJBWvpalMpkRAgKOAKCgZiNdHgL5zyIcrjKp9W8/2gW2JACfVcWz HdAOjT+DS6ysVohTUtNg9Fg= =pGDK -----END PGP SIGNATURE-----
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