From owner-freebsd-hackers@FreeBSD.ORG Sat Jan 31 18:00:45 2004 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 2935A16A4CE for ; Sat, 31 Jan 2004 18:00:45 -0800 (PST) Received: from server.lab.cyberlifelabs.com (adsl-64-142-24-131.sonic.net [64.142.24.131]) by mx1.FreeBSD.org (Postfix) with ESMTP id A55B543D1F for ; Sat, 31 Jan 2004 18:00:43 -0800 (PST) (envelope-from milo@cyberlifelabs.com) Received: from [192.168.1.3] (beastie.lab.cyberlifelabs.com [192.168.1.3]) i1120dvn067760; Sat, 31 Jan 2004 18:00:40 -0800 (PST) (envelope-from milo@cyberlifelabs.com) From: Milo Hyson To: Julian Elischer In-Reply-To: References: Content-Type: text/plain Message-Id: <1075600839.50745.7.camel@beastie.lab.cyberlifelabs.com> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.5 Date: Sat, 31 Jan 2004 18:00:39 -0800 Content-Transfer-Encoding: 7bit cc: freebsd-hackers@freebsd.org Subject: Re: Weird context-switching performance X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 01 Feb 2004 02:00:45 -0000 We don't have any other systems that are as similar as the two in the test, however we did plot context-switching performance against CPU and memory performance on several systems to see if anything jumped out. We found that beastie (the 2200+) is doing only about 26% of the task-switches/dhrystone that the other systems were, which were all pretty much about equal with each other. This is consistent with the observation that appserver (the 2100+) is four-times as fast. I think we can probably conclude that beastie is running slower than it should. So the question still remains. What could affect context-switching to this degree yet not show up in other benchmarks? -- Milo Hyson Chief "Mad" Scientist CyberLife Labs, LLC On Sat, 2004-01-31 at 15:35, Julian Elischer wrote: > On Sat, 31 Jan 2004, Milo Hyson wrote: > > > We've got these two very similar machines that are exhibiting > > drastically different context-switching performance. The slower of the > > two is actually task-switching at four times the rate of the other. > > We've gone through several benchmarks and are at a complete loss to > > explain it. We've set up a page documenting our efforts: > > > > http://www.cyberlifelabs.com/cs-benchmark/ > > > > I would appreciate it if someone could offer some insight into what > > affects context-switching. Is there some obscure kernel variable that > > we've overlooked? Or is it just one of those unexplainable feng-shui > > situations? > > > > Which is the abnormal machine? > i.e. is machine 1 faster than all other similar machines or is machine B > slower? > > > > > Thanks in advance. > > > > -- > > Milo Hyson > > Chief "Mad" Scientist > > CyberLife Labs, LLC > > > > _______________________________________________ > > freebsd-hackers@freebsd.org mailing list > > http://lists.freebsd.org/mailman/listinfo/freebsd-hackers > > To unsubscribe, send any mail to "freebsd-hackers-unsubscribe@freebsd.org" > >