Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755878Ab1DFLzK (ORCPT ); Wed, 6 Apr 2011 07:55:10 -0400 Received: from mx2.parallels.com ([64.131.90.16]:54953 "EHLO mx2.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755827Ab1DFLzI (ORCPT ); Wed, 6 Apr 2011 07:55:08 -0400 Message-ID: <4D9C5494.1090607@parallels.com> Date: Wed, 6 Apr 2011 06:55:00 -0500 From: Rob Landley User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.14) Gecko/20110223 Thunderbird/3.1.8 MIME-Version: 1.0 To: Jens Axboe CC: Tejun Heo , Pete Clements , linux-kernel , "linux-ide@vger.kernel.org" Subject: Re: Commit 7eaceaccab5f40 causing boot hang. References: <201103291551.p2TFpDqZ001692@clem.clem-digital.net> <4D92C874.7040104@parallels.com> <4D931634.5030807@fusionio.com> <4D933584.5050005@parallels.com> <4D94432D.5080601@fusionio.com> <4D944544.9040705@parallels.com> <4D945247.4080404@fusionio.com> <4D945976.8000401@fusionio.com> <20110331121100.GD3385@htj.dyndns.org> <4D9474AA.4070402@fusionio.com> In-Reply-To: <4D9474AA.4070402@fusionio.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [208.54.86.73] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1163 Lines: 31 On 03/31/2011 07:33 AM, Jens Axboe wrote: > On 2011-03-31 14:11, Tejun Heo wrote: >> Hello, >> >> On Thu, Mar 31, 2011 at 12:37:42PM +0200, Jens Axboe wrote: >>> It seems to hard hang, looks very odd: >> I think more likely failure mode is something is looping in block path >> expecting someone else to do something but as it is busy looping and >> preemption isn't enabled the someone else can't proceed. We had a >> similar problem in md lately. >> >> http://thread.gmane.org/gmane.linux.raid/33020 > > I think this sound exactly right, and also explains why SMP works. And > yes CONFIG_PREEMPT_VOLUNTARY=y is set. > >> If this is the case, a good way to debug would be triggering sysrq-l >> multiple times while the machine is hung and see where the CPU is busy >> looping. > > Doesn't respond to sysrq. I'll poke around. Pulled and retested, still hanging for me right after announcing ext3. Just FYI. Rob -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/