From owner-freebsd-performance@FreeBSD.ORG Fri Feb 22 14:35:52 2008 Return-Path: Delivered-To: freebsd-performance@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 0841C16A402 for ; Fri, 22 Feb 2008 14:35:52 +0000 (UTC) (envelope-from bthielsen@safarivideonetworks.com) Received: from smtp.ltn.lvc.com (static-66-14-195-72.bdsl.verizon.net [66.14.195.72]) by mx1.freebsd.org (Postfix) with ESMTP id B02E513C442 for ; Fri, 22 Feb 2008 14:35:51 +0000 (UTC) (envelope-from bthielsen@safarivideonetworks.com) Received: from localhost (localhost [127.0.0.1]) by macgyver.ltn.lvc.com (Postfix) with ESMTP id 56D196A0C34 for ; Fri, 22 Feb 2008 09:35:50 -0500 (EST) X-Virus-Scanned: Debian amavisd-new at macgyver.ltn.lvc.com Received: from macgyver.ltn.lvc.com ([127.0.0.1]) by localhost (macgyver.ltn.lvc.com [127.0.0.1]) (amavisd-new, port 10024) with LMTP id WYxS86DS5fkc for ; Fri, 22 Feb 2008 09:35:45 -0500 (EST) Received: from heliax.ltn.lvc.com (heliax.ltn.lvc.com [10.10.101.200]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by macgyver.ltn.lvc.com (Postfix) with ESMTP id 9A9376A0C33 for ; Fri, 22 Feb 2008 09:35:45 -0500 (EST) Message-Id: <2E9A88C1-067C-4C9C-A062-42203F47BF1C@safarivideonetworks.com> From: benjamin thielsen To: freebsd-performance@freebsd.org In-Reply-To: <47BE0016.6020407@FreeBSD.org> Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (Apple Message framework v919.2) Date: Fri, 22 Feb 2008 09:35:45 -0500 References: <47BE0016.6020407@FreeBSD.org> X-Mailer: Apple Mail (2.919.2) Subject: Re: performance degradation in 6.2 when adding a second quad core chip X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 22 Feb 2008 14:35:52 -0000 On Feb 21, 2008, at 17.49, Kris Kennaway wrote: > benjamin thielsen wrote: >> hi folks- >> we've been experiencing some interesting behavior on single quad >> core computers as compared to dual quad core computers. > > Yes, this can happen when you run into concurrency bottlenecks in > the application or in the kernel. > >> it appears that adding a second processor to the system (leaving it >> otherwise untouched) actually decreases performance. we've got a >> small rudimentary test process, built in house, that does >> postgresql queries (selects) via http requests (apache2/php5). > > 7.0 will perform much better than 6.x on SMP workloads in general, > however TCP I/O is not yet at the point where it can make efficient > use of many processors (there has been a lot of work on TCP in 7.0, > but it is not yet at the stage where a performance payoff will be > seen with more than about 4 CPUs). This is one of the projects that > we will be working on this year, so you can expect future releases > to have improved concurrent TCP performance. > > There may be other issues, so if you like you can enable > LOCK_PROFILING and obtain a trace when your workload is running (see > the manpage). You should also try the ULE scheduler on 7.0. i apologize - i neglected to mention that we are using ule on 7.0. what do you guys generally endorse/recommend for local(non-network) load/performance testing? -ben