From owner-freebsd-stable@FreeBSD.ORG Thu May 5 03:55:51 2005 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id AC89716A4CE for ; Thu, 5 May 2005 03:55:51 +0000 (GMT) Received: from carver.gumbysoft.com (carver.gumbysoft.com [66.220.23.50]) by mx1.FreeBSD.org (Postfix) with ESMTP id 8471C43D45 for ; Thu, 5 May 2005 03:55:51 +0000 (GMT) (envelope-from dwhite@gumbysoft.com) Received: by carver.gumbysoft.com (Postfix, from userid 1000) id D265172DD4; Wed, 4 May 2005 20:54:23 -0700 (PDT) Received: from localhost (localhost [127.0.0.1]) by carver.gumbysoft.com (Postfix) with ESMTP id CDBBB72DCB for ; Wed, 4 May 2005 20:54:23 -0700 (PDT) Date: Wed, 4 May 2005 20:54:23 -0700 (PDT) From: Doug White To: stable@freebsd.org In-Reply-To: <20050503115344.S26250@carver.gumbysoft.com> Message-ID: <20050504205315.K40602@carver.gumbysoft.com> References: <20050503115344.S26250@carver.gumbysoft.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Subject: Re: Experimental ttwwakeup() panic patch X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 05 May 2005 03:55:51 -0000 On Tue, 3 May 2005, Doug White wrote: > Hey folks, > > I've taken a crack at working around the ttwwakeup() panic thats been > reported now and again. My early analysis, based on debugging output from > rwatson, is that a defunct struct tty gets reused without cleaning out the > associated (stale) knote structures, and the ttwwakeup() at the end of > sioopen() jumps off into space when it finds them. > > This patch is against RELENG_5 but the logic should apply to -CURRENT, > although the patch likely won't as ttymalloc() is organized differently > there. > > I did some basic testing on my UP box and didn't see any abberant behavior > afterwards. However I can't reproduce the panic in question, so if you're > good at triggering the panic give this a spin. > > http://people.freebsd.org/~dwhite/tty.c.20050503.patch This patch has been committed and exists as rev 1.228.2.4 of src/sys/kern/tty.c. Please let me know if this fixes the panic for you, or causes new problems :) -- Doug White | FreeBSD: The Power to Serve dwhite@gumbysoft.com | www.FreeBSD.org