From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261728AbULUKYI (ORCPT ); Tue, 21 Dec 2004 05:24:08 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261729AbULUKYI (ORCPT ); Tue, 21 Dec 2004 05:24:08 -0500 Received: from piglet.wetlettuce.com ([82.68.149.69]:41088 "EHLO piglet.wetlettuce.com") by vger.kernel.org with ESMTP id S261728AbULUKYB (ORCPT ); Tue, 21 Dec 2004 05:24:01 -0500 Message-ID: <52121.192.102.214.6.1103624620.squirrel@webmail.wetlettuce.com> Date: Tue, 21 Dec 2004 10:23:40 -0000 (GMT) Subject: Re: Lockup with 2.6.9-ac15 related to netconsole From: "Mark Broadbent" To: In-Reply-To: <20041221005521.GD5974@waste.org> References: <59719.192.102.214.6.1103214002.squirrel@webmail.wetlettuce.com> <20041216211024.GK2767@waste.org> <34721.192.102.214.6.1103274614.squirrel@webmail.wetlettuce.com> <20041217215752.GP2767@waste.org> <20041217233524.GA11202@electric-eye.fr.zoreil.com> <36901.192.102.214.6.1103535728.squirrel@webmail.wetlettuce.com> <20041220211419.GC5974@waste.org> <20041221002218.GA1487@electric-eye.fr.zoreil.com> <20041221005521.GD5974@waste.org> X-Priority: 3 Importance: Normal X-MSMail-Priority: Normal Cc: , , Reply-To: markb@wetlettuce.com X-Mailer: SquirrelMail (version 1.2.6) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-MailScanner: Mail is clear of Viree Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Matt Mackall said: > On Tue, Dec 21, 2004 at 01:22:18AM +0100, Francois Romieu wrote: >> Matt Mackall : >> > On Mon, Dec 20, 2004 at 09:42:08AM -0000, Mark Broadbent wrote: >> > > >> > > Exactly the same happens, I still get a 'NMI Watchdog detected >> > > LOCKUP' with the r8169 device using the above patch on top of >> > > 2.6.10-rc3-bk10. >> > >> > Ok, that suggests a problem localized to netpoll itself. Do you have >> > spinlock debugging turned on by any chance? >> >> Any chance of: >> 1 dev_queue_xmit >> 2 dev->xmit_lock taken >> 3 interruption >> 4 printk >> 5 netconsole write >> 6 dev->xmit_lock again >> 7 lockup >> >> ? >> >> This is probably the silly question of the day. > > Maybe, but the answer isn't obvious to me at the moment as I haven't > been thinking about such stuff enough lately. Silly response of the > day: > > Mark, can you try this (again completely untested, but at least > compiles) patch? I'm afraid I don't have a proper test rig to > reproduce this at the moment. This will attempt to grab the lock, and > if it fails, will check for recursion. Then it will try to print a > message on the local console, temporarily disabling netconsole to > allow the printk to get through.. OK, patch applied and spinlock debugging enabled. Testing with eth1 (r1869) doesn'tyield any additional messages, just the standard 'NMI Watchdog detected lockup'. Thanks Mark -- Mark Broadbent Web: http://www.wetlettuce.com