Date: Tue, 22 Jun 1999 14:07:03 -0500 (CDT) From: Jim Bryant <jbryant@argus.tfs.net> To: rob@ControlQ.com (Robert S. Sciuk) Cc: freebsd-smp@freebsd.org Subject: Re: Multi processor support? Message-ID: <199906221907.OAA95303@argus.tfs.net> In-Reply-To: <Pine.UW2.3.96.990622115629.10127A-100000@fatlady.controlq.com> from "Robert S. Sciuk" at "Jun 22, 99 12:00:15 pm"
next in thread | previous in thread | raw e-mail | index | archive | help
In reply: > On Mon, 21 Jun 1999, Gregory Sutter wrote: > > > On Mon, Jun 21, 1999 at 11:59:52PM +0000, Terry Lambert wrote: > > > > Also, is there any way to control what processes happen on > > > > which cpu? > > > > > > Heh. That wouldn't be very symmetric... > > > > No, but having processor affinity would be quite nice. There's > > nothing wrong with MP. > > Processor affinity is more than nice. Work I've done on large HP boxes > indicate that by putting producer/consumer processes on the same processor > one avoids a lot of cache coherency issues, and increases bandwidth > considerably. Admittedly, this is not true of all applications, but > having the ability to have two or more processes share a processor can go > a long way towards tuning application performance. I would suggest an > ioctl or other API type interface, with a userland tool to assist ... good idea. Tandem, and Convex [now part of HP], are two other companies that explicitly allow you to define such overrides as the max number of cpu's a process can run on, the specific cpus to run on, etc... This can be very handy in hand optimization of production systems. jim -- All opinions expressed are mine, if you | "I will not be pushed, stamped, think otherwise, then go jump into turbid | briefed, debriefed, indexed, or radioactive waters and yell WAHOO !!! | numbered!" - #1, "The Prisoner" ------------------------------------------------------------------------------ Inet: jbryant@tfs.net AX.25: kc5vdj@wv0t.#neks.ks.usa.noam grid: EM28pw voice: KC5VDJ - 6 & 2 Meters AM/FM/SSB, 70cm FM. http://www.tfs.net/~jbryant ------------------------------------------------------------------------------ HF/6M/2M: IC-706-MkII, 2M: HTX-212, 2M: HTX-202, 70cm: HTX-404, Packet: KPC-3+ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199906221907.OAA95303>