Date: Fri, 9 Jul 2004 11:19:55 +0900 From: Taku YAMAMOTO <taku@tackymt.homeip.net> To: John Baldwin <jhb@FreeBSD.org> Cc: freebsd-current@FreeBSD.org Subject: Re: Native preemption is the culprit [was Re: today's CURRENT lockups] Message-ID: <20040709111955.2901ce5b.taku@tackymt.homeip.net> In-Reply-To: <200407081317.53981.jhb@FreeBSD.org> References: <20040705184940.GA2651@tybalt.greiner.local> <Pine.NEB.3.96L.1040706001249.2853I-100000@fledge.watson.org> <20040708222143.0f24c076.taku@tackymt.homeip.net> <200407081317.53981.jhb@FreeBSD.org>
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On Thu, 8 Jul 2004 13:17:53 -0400 John Baldwin <jhb@FreeBSD.org> 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? -- -|-__ YAMAMOTO, Taku | __ < <taku@tackymt.homeip.net> Post Scriptum to the people who know me as taku@cent.saitama-u.ac.jp: My email address has been changed since April, because I've left the university.
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