From owner-freebsd-current@FreeBSD.ORG Thu Dec 11 19:08:55 2008 Return-Path: Delivered-To: current@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id DA532106567A; Thu, 11 Dec 2008 19:08:55 +0000 (UTC) (envelope-from rwatson@FreeBSD.org) Received: from cyrus.watson.org (cyrus.watson.org [65.122.17.42]) by mx1.freebsd.org (Postfix) with ESMTP id B7E3F8FC13; Thu, 11 Dec 2008 19:08:55 +0000 (UTC) (envelope-from rwatson@FreeBSD.org) Received: from fledge.watson.org (fledge.watson.org [65.122.17.41]) by cyrus.watson.org (Postfix) with ESMTP id 5403846B2E; Thu, 11 Dec 2008 14:08:55 -0500 (EST) Date: Thu, 11 Dec 2008 19:08:55 +0000 (GMT) From: Robert Watson X-X-Sender: robert@fledge.watson.org To: Roman Divacky In-Reply-To: <20081211174023.GA57297@freebsd.org> Message-ID: References: <20081210164345.GA32188@freebsd.org> <20081210214248.GA69246@freebsd.org> <20081211174023.GA57297@freebsd.org> User-Agent: Alpine 1.10 (BSF 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: current@FreeBSD.org Subject: Re: [PANIC]: rw_lock panic in in_pcballoc() in r185864 X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 11 Dec 2008 19:08:55 -0000 On Thu, 11 Dec 2008, Roman Divacky wrote: >>> I have the crash dump and the kernel at hand so I can do basically >>> anything you ask me to do :) anything I can provide? >> >> Well, to be honest, the easiest thing to do may be to play the binary >> search game to narrow down the point where the problem starts a bit more. >> There are a few kinds of things that might lead to this problem -- perhaps >> we (I?) mucked up initialization of the inpcb with recent changes, or a >> virtualization-related change tripped something up, or a locking/scheduler >> change or such. > > it's something between 185772 and 185864, dont you have any dhcp-enabled > machine? if so.. can you reproduce that? I have several boxes, real and virtual, using DHCP and very recent (tm) kernels and no sign of this panic. That's why I think there's something going on here that's a bit more subtle. For example, we'd really like to know what in the rw_wlock() call got tripped over as a NULL pointer... >> The other thing that would be helpful is a dump of *inp so that we can see >> what state inp_lock is in. > > I foolishly deleted the kernel matching the vmcore, I'll try to do that > tomorrow OK. Once you get the panic, I think the most interesting questions have to do with the contents of *inp, *inp->inp_lock.lock_object, etc. It might also be interesting to know whether any UDP use triggers the panic, or just DHCP. You can test this by booting to single-user, configuring lo0 manually, and then doing "dig @127.0.0.1 ." or some other activity that triggers a UDP packet to be sent. Robert N M Watson Computer Laboratory University of Cambridge