From owner-freebsd-current@FreeBSD.ORG Fri Jul 9 17:14:06 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 8243D16A4CE for ; Fri, 9 Jul 2004 17:14:06 +0000 (GMT) Received: from mail1.speakeasy.net (mail1.speakeasy.net [216.254.0.201]) by mx1.FreeBSD.org (Postfix) with ESMTP id 2694143D1D for ; Fri, 9 Jul 2004 17:14:06 +0000 (GMT) (envelope-from jhb@FreeBSD.org) Received: (qmail 8506 invoked from network); 9 Jul 2004 17:14:05 -0000 Received: from dsl027-160-063.atl1.dsl.speakeasy.net (HELO server.baldwin.cx) ([216.27.160.63]) (envelope-sender ) encrypted SMTP for ; 9 Jul 2004 17:14:05 -0000 Received: from 10.50.41.229 (gw1.twc.weather.com [216.133.140.1]) by server.baldwin.cx (8.12.11/8.12.11) with ESMTP id i69HE1mg088656; Fri, 9 Jul 2004 13:14:01 -0400 (EDT) (envelope-from jhb@FreeBSD.org) From: John Baldwin To: freebsd-current@FreeBSD.org Date: Fri, 9 Jul 2004 13:15:16 -0400 User-Agent: KMail/1.6 References: <20040705184940.GA2651@tybalt.greiner.local> <200407081317.53981.jhb@FreeBSD.org> <20040709111955.2901ce5b.taku@tackymt.homeip.net> In-Reply-To: <20040709111955.2901ce5b.taku@tackymt.homeip.net> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200407091315.16899.jhb@FreeBSD.org> X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on server.baldwin.cx cc: Taku YAMAMOTO Subject: Re: Native preemption is the culprit [was Re: today's CURRENT lockups] X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 09 Jul 2004 17:14:06 -0000 On Thursday 08 July 2004 10:19 pm, Taku YAMAMOTO wrote: > On Thu, 8 Jul 2004 13:17:53 -0400 > > John Baldwin wrote: > > On Thursday 08 July 2004 09:21 am, Taku YAMAMOTO wrote: > > > greetings, > > > > > > > > > A quick glance showed me that there are some interesting code paths in > > > sched_ule.c that can be problematic in SMP case. > > > > > > 1. sched_choose() => kseq_idled() => sched_add() > > > 2. sched_choose() => kseq_assign() => sched_add() > > > 3. sched_runnable() => kseq_assign() => sched_add() > > > > > > Here is the patch that re-enables preemption except for the above three > > > cases. > > > > This looks correct. I'll test it locally first. Has it worked for you > > all day? > > My machine (HTT) has been up for 20 hours without a hang since last update. > I tried to stress it in various ways (fsck -n, buildworld & buildkernel in > parallel, burning a CD, etc.) but failed to crash it. > > I'm bit afraid since the code is not tested on real SMP machines. > How is it going on yours? My test machine is not a true SMP machine either, just HTT. It has been running a -j 256 worldloop overnight with no problems, so I committed a slightly modified version of the patch yesterday. -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.org