From owner-freebsd-hackers@FreeBSD.ORG Fri Apr 1 18:38:41 2005 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id EDFF616A4CE for ; Fri, 1 Apr 2005 18:38:41 +0000 (GMT) Received: from mail26.sea5.speakeasy.net (mail26.sea5.speakeasy.net [69.17.117.28]) by mx1.FreeBSD.org (Postfix) with ESMTP id 88D2A43D58 for ; Fri, 1 Apr 2005 18:38:41 +0000 (GMT) (envelope-from jhb@FreeBSD.org) Received: (qmail 13684 invoked from network); 1 Apr 2005 18:38:41 -0000 Received: from server.baldwin.cx ([216.27.160.63]) (envelope-sender )AES256-SHA encrypted SMTP for ; 1 Apr 2005 18:38:40 -0000 Received: from [10.50.41.231] (gw1.twc.weather.com [216.133.140.1]) (authenticated bits=0) by server.baldwin.cx (8.13.1/8.13.1) with ESMTP id j31IcX0j034575; Fri, 1 Apr 2005 13:38:34 -0500 (EST) (envelope-from jhb@FreeBSD.org) From: John Baldwin To: freebsd-hackers@FreeBSD.org Date: Fri, 1 Apr 2005 11:20:27 -0500 User-Agent: KMail/1.6.2 References: In-Reply-To: MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Message-Id: <200504011120.27285.jhb@FreeBSD.org> X-Spam-Status: No, score=-102.8 required=4.2 tests=ALL_TRUSTED, USER_IN_WHITELIST autolearn=failed version=3.0.2 X-Spam-Checker-Version: SpamAssassin 3.0.2 (2004-11-16) on server.baldwin.cx cc: William Michael Grim cc: Poul-Henning Kamp cc: Robert Watson Subject: Re: 4BSD Scheduler Problem on 5.3 X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 01 Apr 2005 18:38:42 -0000 On Thursday 31 March 2005 08:03 pm, Robert Watson wrote: > On Thu, 31 Mar 2005, John Baldwin wrote: > > On Thursday 31 March 2005 03:38 pm, William Michael Grim wrote: > > > Hello. > > > > > > I keep having kernel panics every couple weeks on my system. It occurs > > > in the sched_switch() function. There are several other statements in > > > the backtrace involving "??"; what are those? > > > > > > I have attached the dump output and system info to this email. Any > > > feedback would be helpful. > > > > > > Thanks so much for your help. > > > > The real trace ends with Xint0x80_syscall(). The rest after that is > > garbage memory. Your real problem is in exit1() or ttywakeup(). Since > > ttywakeup() doesn't call exit1() (AFAIK), the exit1() frame is probably > > bogus (gdb doesn't grok trapframes maybe?) and the real bug is a NULL > > pointer deref in ttywakeup(). Perhaps it's a bug in the ptc driver? > > (ptcopen is in the trace). What is the ptc driver anyway? > > I think we have a race in -STABLE relating to tty wakeups and > open/close/device teardown. I've seen a panic relating to sio during a > tty close on RELENG_5 about 5-6 months ago, but was unable to get a dump. > Scott has since fixed dumps with twe, but I've not yet been able to get > the bug to recur. I'll give it another try. Sounds very plausible. Does Poul-Henning have any ideas? -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.org