From owner-cvs-all@FreeBSD.ORG Wed Jan 21 10:14:29 2004 Return-Path: Delivered-To: cvs-all@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 82CFA16A4CF for ; Wed, 21 Jan 2004 10:14:29 -0800 (PST) Received: from mail4.speakeasy.net (mail4.speakeasy.net [216.254.0.204]) by mx1.FreeBSD.org (Postfix) with ESMTP id AD04F43D53 for ; Wed, 21 Jan 2004 10:14:17 -0800 (PST) (envelope-from jhb@FreeBSD.org) Received: (qmail 6190 invoked from network); 21 Jan 2004 18:14:17 -0000 Received: from dsl027-160-063.atl1.dsl.speakeasy.net (HELO server.baldwin.cx) ([216.27.160.63]) (envelope-sender ) encrypted SMTP for ; 21 Jan 2004 18:14:17 -0000 Received: from 10.50.40.205 (gw1.twc.weather.com [216.133.140.1]) by server.baldwin.cx (8.12.10/8.12.10) with ESMTP id i0LIDxMA019746; Wed, 21 Jan 2004 13:14:13 -0500 (EST) (envelope-from jhb@FreeBSD.org) From: John Baldwin To: Nate Lawson , "Greg 'groggy' Lehey" Date: Wed, 21 Jan 2004 11:15:48 -0500 User-Agent: KMail/1.5.4 References: <200401192127.i0JLRBL3041817@repoman.freebsd.org> <20040121004238.GP47639@wantadilla.lemis.com> <20040120164435.I98793@root.org> In-Reply-To: <20040120164435.I98793@root.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200401211115.48851.jhb@FreeBSD.org> X-Spam-Checker-Version: SpamAssassin 2.55 (1.174.2.19-2003-05-19-exp) cc: cvs-src@FreeBSD.org cc: src-committers@FreeBSD.org cc: Poul-Henning Kamp cc: cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/alpha/alpha support.s src/sys/i386/i386 swtch.s src/sys/kern kern_shutdown.c src/sys/sys systm.h X-BeenThere: cvs-all@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: CVS commit messages for the entire tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 21 Jan 2004 18:14:29 -0000 On Tuesday 20 January 2004 08:04 pm, Nate Lawson wrote: > On Wed, 21 Jan 2004, Greg 'groggy' Lehey wrote: > > On Tuesday, 20 January 2004 at 11:31:03 -0800, Nate Lawson wrote: > > > * GDB over Ethernet > > > > We have GDB over firewire. Ethernet would be nice too, but firewire > > actually does more. Take a look at gdb(4) (new man page). > > I'm glad to have this. More machines have ethernet than firewire ports > though. > > > > We don't need file/line added to the panic message since panic > > > messages are unambiguous. > > > > You still need to grep for them. > > There are basically two kinds of panics: assertions and page faults. > Assertions, whether KASSERT or explicit checks/panic calls, give a unique, > easily identified message ("foo driver: invalid mbuf length, %d"). If > this is not obvious enough even without grep, then the panic message > should be fixed. There is no difference between "vi +line file.c" and > "vi file.c /msg", hence phk's commit is not useful in this case. > > Page faults are much harder to track down from the start. You find > whether or not it was a NULL pointer, the curproc, and PC. So the next > step is to have them recompile with options DDB or preferably -g and type > "tr" at the DDB prompt. The changes to panic do not help this case at all > since you get the file and line of the page fault handler. > > I would have gotten 100x more value from making options DDB the default in > GENERIC (at least until we branch -stable) and having all page faults > generate a backtrace. This is a 1 line change that would save hours, not > minutes, of roundtrip email. Look at reports of panics in the > freebsd-current@ archives and see how many result in a request for a > backtrace. DDB is on GENERIC. Just DDB_TRACE is not on. -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.org