From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2992522AbXDYKCY (ORCPT ); Wed, 25 Apr 2007 06:02:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S2992549AbXDYKCX (ORCPT ); Wed, 25 Apr 2007 06:02:23 -0400 Received: from wasp.net.au ([203.190.192.17]:48393 "EHLO wasp.net.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2992522AbXDYKCX (ORCPT ); Wed, 25 Apr 2007 06:02:23 -0400 Message-ID: <462F2727.7090205@wasp.net.au> Date: Wed, 25 Apr 2007 14:02:15 +0400 From: Brad Campbell User-Agent: Thunderbird 1.5.0.10 (X11/20070306) MIME-Version: 1.0 To: Jens Axboe CC: Neil Brown , Chuck Ebbert , lkml Subject: Re: [OOPS] 2.6.21-rc6-git5 in cfq_dispatch_insert References: <17956.22235.574867.179016@notabene.brown> <20070418123757.GC3796@kernel.dk> <46261ACE.1050407@wasp.net.au> <20070418132157.GC3720@kernel.dk> <462B10C3.1030906@wasp.net.au> <20070423073543.GE5311@kernel.dk> <462E5D38.5000801@wasp.net.au> <17967.4734.783140.512857@notabene.brown> <20070425084607.GM9715@kernel.dk> <17967.8536.788076.851546@notabene.brown> <20070425094712.GP9715@kernel.dk> In-Reply-To: <20070425094712.GP9715@kernel.dk> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Jens Axboe wrote: > It looks to be extremely rare. Aliases are extremely rare, front merges > are rare. And you need both to happen with the details you outlined. But > it's a large user base, and we've had 3-4 reports on this in the past > months. So it obviously does happen. I could not make it trigger without > doctoring the unplug code when I used aio. Well, not that rare on this particular machine (I had a case where I could reproduce it in less than an hour of normal use previously on this box), and I've had it occur a number of times on my servers, I just never reported it before as I never took the time to set up a serial console and capture the oops. > Here's a fix for it, confirmed. Shall I leave the other debugging in, apply this and run it for a few hard days? Brad -- "Human beings, who are almost unique in having the ability to learn from the experience of others, are also remarkable for their apparent disinclination to do so." -- Douglas Adams