From owner-cvs-src@FreeBSD.ORG Tue Jan 20 17:04:18 2004 Return-Path: Delivered-To: cvs-src@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 8F58916A4D1 for ; Tue, 20 Jan 2004 17:04:18 -0800 (PST) Received: from root.org (root.org [67.118.192.226]) by mx1.FreeBSD.org (Postfix) with SMTP id 01B4343D5A for ; Tue, 20 Jan 2004 17:04:11 -0800 (PST) (envelope-from nate@root.org) Received: (qmail 98968 invoked by uid 1000); 21 Jan 2004 01:04:12 -0000 Date: Tue, 20 Jan 2004 17:04:12 -0800 (PST) From: Nate Lawson To: Greg 'groggy' Lehey In-Reply-To: <20040121004238.GP47639@wantadilla.lemis.com> Message-ID: <20040120164435.I98793@root.org> References: <200401192127.i0JLRBL3041817@repoman.freebsd.org> <20040120015009.W39477@odysseus.silby.com> <20040121004238.GP47639@wantadilla.lemis.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII 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-src@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: CVS commit messages for the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 21 Jan 2004 01:04:18 -0000 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. -Nate