From owner-freebsd-arch@FreeBSD.ORG Tue Sep 28 07:49:29 2004 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id CA26716A4CE for ; Tue, 28 Sep 2004 07:49:29 +0000 (GMT) Received: from relay.pair.com (relay.pair.com [209.68.1.20]) by mx1.FreeBSD.org (Postfix) with SMTP id 571C543D31 for ; Tue, 28 Sep 2004 07:49:29 +0000 (GMT) (envelope-from pho@holm.cc) Received: (qmail 44107 invoked from network); 28 Sep 2004 07:49:27 -0000 Received: from 0x50a43fc7.hknxx1.adsl-dhcp.tele.dk (HELO peter.osted.lan) (80.164.63.199) by relay.pair.com with SMTP; 28 Sep 2004 07:49:27 -0000 X-pair-Authenticated: 80.164.63.199 Received: from peter.osted.lan (localhost.osted.lan [127.0.0.1]) by peter.osted.lan (8.12.10/8.12.10) with ESMTP id i8S7nRCs099983; Tue, 28 Sep 2004 09:49:27 +0200 (CEST) (envelope-from pho@peter.osted.lan) Received: (from pho@localhost) by peter.osted.lan (8.12.10/8.12.10/Submit) id i8S7nQxS099982; Tue, 28 Sep 2004 09:49:26 +0200 (CEST) (envelope-from pho) Date: Tue, 28 Sep 2004 09:49:26 +0200 From: Peter Holm To: Stephan Uphoff Message-ID: <20040928074926.GA99957@peter.osted.lan> References: <1095468747.31297.241.camel@palm.tree.com> <414B8D5E.7000700@elischer.org> <1095529353.31297.1192.camel@palm.tree.com> <1096135220.53798.17754.camel@palm.tree.com> <41563C95.2020501@elischer.org> <20040926075218.GA85983@peter.osted.lan> <1096339936.3733.279.camel@palm.tree.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1096339936.3733.279.camel@palm.tree.com> User-Agent: Mutt/1.4.1i cc: Peter Holm cc: Julian Elischer cc: "freebsd-arch@freebsd.org" Subject: Re: scheduler (sched_4bsd) questions X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 28 Sep 2004 07:49:29 -0000 On Mon, Sep 27, 2004 at 10:52:16PM -0400, Stephan Uphoff wrote: > On Sun, 2004-09-26 at 03:52, Peter Holm wrote: > > On Sat, Sep 25, 2004 at 08:50:45PM -0700, Julian Elischer wrote: > > > Stephan Uphoff wrote: > > > > > > >>Maybe something brutal like: > > > >> if ((curthread->td_ksegrp == kg) && > > > >> (td->td_priority > curthread->td_priority)) > > > >> curthread->td_flags |= TDF_NEEDRESCHED; > > > >> > > > >>in setrunqueue for > > > >>the else case of "if (kg->kg_avail_opennings > 0)" > > > >>would do the trick (without preemption) for the easy but probably more > > > >>common cases? > > > >> > > > >>Maybe I can find some time next week to think about a clean > > > >>fix. I find it always helpful having a small task in mind while reading > > > >>source code. > > > > > > > > > > > >I wrote a fix that should cover all cases. > > > >However I would like to test it a little bit before posting the patch. > > > >Is there any multi-threaded kernel torture program that you can > > > >recommend? > > > > > > > > > Peter Holm (CC'd) has a really cool set of torture tests. > > > he has also seen all sorts of failures others have not (yet) triggered. :-) > > > > > > I'm 'busy" for the next couple of weeks so you may want to communicate > > > directly with him and see if you and he together can figure out some of the > > > things he's > > > been seeing :-) > > > > > > his tests are at: > > > http://www.holm.cc/stress/src/stress.tgz > > > > > > > > > > >Thanks > > > > > > > > Stephan > > > > > > > > I'll be glad to test any patches. > > Great. > Can you try the attached patch to see if it changes any of your > previously observed behaviour? > The system still freezes and can be unfrozen by a ping: http://www.holm.cc/stress/log/stephan.html -- Peter Holm