Date: Tue, 20 Apr 2004 09:45:47 -0500 From: "Jim C. Nasby" <jim@nasby.net> To: freebsd-performance@freebsd.org Subject: Re: command piped into bzip not using all available CPU Message-ID: <20040420144547.GX87362@nasby.net> In-Reply-To: <20040420032716.GC56561@laptop.lambertfam.org> References: <20040416220556.GL87362@nasby.net> <002701c42404$e9dbecf0$3102a8c0@metallus> <20040419022239.GP87362@nasby.net> <001801c425dd$1fda0b00$3102a8c0@metallus> <20040419140921.GS87362@nasby.net> <20040420032716.GC56561@laptop.lambertfam.org>
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decibel@fritz.1[9:34]~:6>uname -a FreeBSD fritz.distributed.net 5.2.1-RELEASE FreeBSD 5.2.1-RELEASE #1: Wed Apr 7 18:42:52 CDT 2004 root@fritz.distributed.net:/usr/obj/usr/src/sys/FRITZ amd64 decibel@fritz.1[9:35]/usr/src/sys/amd64/conf:9>grep -i sched FRITZ options SCHED_4BSD #4BSD scheduler options _KPOSIX_PRIORITY_SCHEDULING #Posix P1003_1B real-time extensions Also, don't read anything into the fact that they were on the same CPU for that snapshot; here's one showing the exact opposite: PID USERNAME PRI NICE SIZE RES STATE C TIME WCPU CPU COMMAND 10336 dnetc 139 20 1344K 856K RUN 1 80.5H 90.14% 90.14% dnetc 10702 decibel 108 0 10856K 7304K CPU0 1 0:13 23.86% 22.41% bzip2 10703 pgsql 4 0 154M 78004K sbwait 0 0:07 10.92% 10.25% postgres FWIW, I recall seeing this same behavior under FreeBSD 4.x as well. On Mon, Apr 19, 2004 at 11:27:16PM -0400, Scott Lambert wrote: > On Mon, Apr 19, 2004 at 09:09:21AM -0500, Jim C. Nasby wrote: > > Why would I expect to see it only use one CPU? It was CPU bound, not > > disk bound. There were two CPU-intensive processes running, why wouldn't > > they each use a different CPU? > > > > On Mon, Apr 19, 2004 at 12:08:32AM -0700, Aaron Seelye wrote: > > > I'm not sure the exact technical reason, but as I understand that, it's > > > 47% idle on the total cpu power of the machine, which would indicate > > > that one cpu was 100% full, and the other was 3%, due to system usage, > > > i/o, or whatever else was running. This is quite normal in my > > > experience, and what you should expect to see. > > At the time you took the snapshot, both processes were running on the > same CPU. FreeBSD 4.x or 5.2? If 5.2, SCHED_4BSD or SCHED_ULE? > > > > > The command I'm running is: > > > > pg_dump -vZ0 ogr | bzip2 > ogr-20040416.sql.bz2 > > > > > > > > PID USERNAME PRI NICE SIZE RES STATE C TIME WCPU CPU COMMAND > > > > 17334 decibel 109 0 10856K 7164K CPU0 0 11:05 65.77% 65.77% bzip2 > > > > 17335 pgsql 4 0 154M 124M sbwait 0 5:54 34.03% 34.03% postgres > > > > 17333 decibel -8 0 20128K 3236K pipdwt 0 0:46 2.88% 2.88% pg_dump > > -- > Scott Lambert KC5MLE Unix SysAdmin > lambert@lambertfam.org > > _______________________________________________ > freebsd-performance@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-performance > To unsubscribe, send any mail to "freebsd-performance-unsubscribe@freebsd.org" > -- Jim C. Nasby, Database Consultant jim@nasby.net Member: Triangle Fraternity, Sports Car Club of America Give your computer some brain candy! www.distributed.net Team #1828 Windows: "Where do you want to go today?" Linux: "Where do you want to go tomorrow?" FreeBSD: "Are you guys coming, or what?"
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