From owner-freebsd-current Mon Sep 24 12:45:54 2001 Delivered-To: freebsd-current@freebsd.org Received: from freebie.xs4all.nl (freebie.xs4all.nl [213.84.32.253]) by hub.freebsd.org (Postfix) with ESMTP id CBBB937B41C; Mon, 24 Sep 2001 12:45:44 -0700 (PDT) Received: (from wkb@localhost) by freebie.xs4all.nl (8.11.6/8.11.6) id f8OJjhS16386; Mon, 24 Sep 2001 21:45:43 +0200 (CEST) (envelope-from wkb) Date: Mon, 24 Sep 2001 21:45:43 +0200 From: Wilko Bulte To: John Baldwin Cc: Garrett Wollman , current@FreeBSD.org Subject: Re: Seen this lock order reversal? Message-ID: <20010924214543.A16350@freebie.xs4all.nl> References: <20010923204929.A11867@freebie.xs4all.nl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: ; from jhb@FreeBSD.org on Mon, Sep 24, 2001 at 12:33:32PM -0700 X-OS: FreeBSD 4.4-STABLE X-PGP: finger wilko@freebsd.org Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Mon, Sep 24, 2001 at 12:33:32PM -0700, John Baldwin wrote: > > On 23-Sep-01 Wilko Bulte wrote: > > On Thu, Sep 20, 2001 at 07:40:52PM +0200, Wilko Bulte wrote: > >> On Wed, Sep 19, 2001 at 01:32:28PM -0700, John Baldwin wrote: > >> > > >> > On 19-Sep-01 Wilko Bulte wrote: > >> > > On Tue, Sep 18, 2001 at 03:01:25PM -0700, John Baldwin wrote: > >> > >> ... > >> > >> > >> p_flag to p_sflag which changed its locking semantics.) > >> > > > >> > > Another one, on a -current from yesterday, on -alpha: > >> > > > >> > > lock order reversal > >> > > 1st 0xfffffc00007fcef0 clk @ ../../../alpha/alpha/clock.c:702 > >> > > 2nd 0xfffffc00007f65d8 callout @ ../../../kern/kern_timeout.c:225 > >> > > ds10# > >> > > >> > Hmm, ok, that one is new and is a problem. Can you turn on WITNESS_DDB > >> > (it's > >> > available as the debug.witness_ddb sysctl and loader variableas well) and > >> > then > >> > get me a traceback in ddb? > >> > >> I built a GENERIC with WITNESS_DDB. Sofar (of course... :-/ ) no > >> reproduction of the problem. I'm running buildworlds, any other good > >> suggestions to help trigger it are welcome > > > > Bah. I cannot reproduce this on my DS10. > > > > Is there any reason to assume that specifying CPUTYPE ev56 has any > > influence on the lock order reversal? By default world is built with > > ev4, but I have gone to ev56 now. Rumor has it that results in 'less > > buggy' code. > > No. Hmmm. You didn't have any KTR traces enabled did you? > > Hmm, that first one is in sysbeep() (the clk one) Ah! It is easy to nuke the system once you know what is wrong: type ^G on the console and *bang* you are in DDB ;) -- | / o / /_ _ email: wilko@FreeBSD.org |/|/ / / /( (_) Bulte Arnhem, The Netherlands To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message