From owner-freebsd-smp Tue Jun 22 9: 1:37 1999 Delivered-To: freebsd-smp@freebsd.org Received: from alpha.netaccess.on.ca (alpha.netaccess.on.ca [199.243.225.10]) by hub.freebsd.org (Postfix) with ESMTP id CE8B114C81; Tue, 22 Jun 1999 09:01:29 -0700 (PDT) (envelope-from rob@ControlQ.com) Received: from fatlady.controlq.com (dial203.nas.net [199.243.225.203]) by alpha.netaccess.on.ca (8.9.0/8.9.0) with SMTP id MAA17834; Tue, 22 Jun 1999 12:00:04 -0400 (EDT) Date: Tue, 22 Jun 1999 12:00:15 -0400 (EDT) From: "Robert S. Sciuk" To: Gregory Sutter Cc: Terry Lambert , dvwd@wwdg.com, freebsd-questions@FreeBSD.ORG, freebsd-smp@FreeBSD.ORG Subject: Re: Multi processor support? In-Reply-To: <19990621182054.G73528@001101.zer0.org> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-smp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org 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 ... -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Robert S. Sciuk 1032 Howard Rd. PO Box 6A Ph:905 632-2466 Control-Q Research Burlington, Ont. Canada Fx:905 632-7417 rob@ControlQ.com L7R 3X5 http://www.ControlQ.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message