From owner-freebsd-current@FreeBSD.ORG Thu Jun 17 17:24:47 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id EA60916A4CE for ; Thu, 17 Jun 2004 17:24:46 +0000 (GMT) Received: from cmsrelay02.mx.net (cmsrelay02.mx.net [165.212.11.111]) by mx1.FreeBSD.org (Postfix) with SMTP id 8DB4443D4C for ; Thu, 17 Jun 2004 17:24:46 +0000 (GMT) (envelope-from noackjr@alumni.rice.edu) Received: from uadvg130.cms.usa.net (165.212.11.130) by cmsoutbound.mx.net with SMTP; 17 Jun 2004 17:24:38 -0000 Received: from optimator.noacks.org [70.240.231.39] by uadvg130.cms.usa.net (ASMTP/noackjr@usa.net) via mtad (C8.MAIN.3.13N) with ESMTP id 826iFqRyj0380M30; Thu, 17 Jun 2004 17:24:35 GMT X-USANET-Auth: 70.240.231.39 AUTH noackjr@usa.net optimator.noacks.org Received: from localhost (localhost [127.0.0.1]) by optimator.noacks.org (Postfix) with ESMTP id 178286153; Thu, 17 Jun 2004 12:24:35 -0500 (CDT) Received: from optimator.noacks.org ([127.0.0.1]) by localhost (optimator.noacks.org [127.0.0.1]) (amavisd-new, port 10024) with LMTP id 51460-08; Thu, 17 Jun 2004 12:24:33 -0500 (CDT) Received: from compgeek.noacks.org (compgeek [192.168.1.10]) by optimator.noacks.org (Postfix) with ESMTP id D0D5C6140; Thu, 17 Jun 2004 12:24:33 -0500 (CDT) Received: from [127.0.0.1] (localhost.noacks.org [127.0.0.1]) by compgeek.noacks.org (8.12.11/8.12.11) with ESMTP id i5HHOXsx061453; Thu, 17 Jun 2004 12:24:33 -0500 (CDT) (envelope-from noackjr@alumni.rice.edu) Message-ID: <40D1D3D1.9010209@alumni.rice.edu> Date: Thu, 17 Jun 2004 12:24:33 -0500 From: Jon Noack User-Agent: Mozilla Thunderbird 0.6 (X11/20040531) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Robert Watson References: In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: by amavisd-new at noacks.org cc: mike cc: Julian Elischer cc: freebsd-threads@freebsd.org cc: freebsd-current@freebsd.org Subject: Re: Possible Threading problem with -CURRENT / MySQL? X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list Reply-To: noackjr@alumni.rice.edu List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 17 Jun 2004 17:24:47 -0000 On 06/17/04 08:00, Robert Watson wrote: > On Thu, 17 Jun 2004, Jon Noack wrote: >> On 06/17/04 01:07, Brad Knowles wrote: >>> At 1:31 AM -0400 2004-06-17, Robert Watson wrote: >>>> - Running with SCHED_4BSD instead of SCHED_ULE >>> >>> This is the only one that really concerns me. This shows that we >>> clearly need more work on ULE. Is there one particular thing >>> that we seem to be tripping up on, or is it a multitude of >>> things? >> >> I think I'll switch to 4BSD until I see more work being done on ULE >> (I read cvs-src as a hobby already so I'll know when to switch >> back). I noticed a performance drop from 5.2.1-p8 (with 4BSD) to >> -CURRENT (with ULE) when I upgraded, but I attributed it to other >> things. However, the system still feels slower than before despite >> having since disabled INVARIANTS, WITNESS, and userspace malloc >> debugging flags. > > ULE seems to do a very good job of scheduling interactive tasks over > other workloads, resulting in a very "snappy" feel on my boxes, > despite heavy CPU load from background builds, etc. The workload I > looked at had no real "interactive" component, although it was a > latency-centric RPC test, so timely hand-off as well as high > throughput would be important. I know that Jeff's measurement work > on ULE had a substantial focus on deadlines -- whether or not ULE was > timely in scheduling tasks, etc, and that he demonstrated that it was > much stronger than most other available schedulers in this area. Well, I switched to 4BSD and noticed this right away. I occasionally get sound hiccups under heavy i/o with ULE [1], but with 4BSD it's a bit ridiculous. There's a PR open about it (can't remember which off the top of my head), but sound will skip and slow down (play at half speed or slower). I know the sound locking is not all it should be, so this may not be a representative test. Regardless, my workstations are back on ULE... Jon [1] Often when using tar or bsdtar. To reproduce: cd /usr/ports/www/firefox; make extract