From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755414Ab1C3BMX (ORCPT ); Tue, 29 Mar 2011 21:12:23 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:62738 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1754945Ab1C3BMW (ORCPT ); Tue, 29 Mar 2011 21:12:22 -0400 Message-ID: <4D92838B.4070706@cn.fujitsu.com> Date: Wed, 30 Mar 2011 09:12:43 +0800 From: Gui Jianfeng User-Agent: Thunderbird 2.0.0.24 (Windows/20100228) MIME-Version: 1.0 To: Jens Axboe CC: Vivek Goyal , lkml Subject: Re: Bug at for-2.6.39/core References: <4D91AAB9.2000800@cn.fujitsu.com> <4D91AB5C.8030203@kernel.dk> In-Reply-To: <4D91AB5C.8030203@kernel.dk> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2011-03-30 09:10:49, Serialize by Router on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2011-03-30 09:10:49, Serialize complete at 2011-03-30 09:10:49 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jens Axboe wrote: > On 2011-03-29 11:47, Gui Jianfeng wrote: >> Hi Jens, >> >> I trigger an OOPS when testing, the following script can reproduce >> this bug on my box. >> >> #!/bin/sh >> >> mkdir /mnt/blkio >> mount -t cgroup -o blkio blkio /mnt/blkio/ >> mkdir /mnt/blkio/test1 /mnt/blkio/test2 >> echo noop > /sys/block/sdb/queue/scheduler >> dd iflag=direct if=/dev/sdb of=/dev/null bs=4k & >> echo $! > /mnt/blkio/test1/tasks >> dd iflag=direct if=/dev/sdb of=/dev/null bs=4k & >> echo $! > /mnt/blkio/test2/tasks >> sleep 3 >> echo cfq > /sys/block/sdb/queue/scheduler >> >> ---- >> eBUG: unable to handle kernel NULL pointer dereference at 0000000000000008 >> IP: [] cfq_completed_request+0x38/0x7f0 > > This is a known bug, update to Linus' current -git and it's fixed. Ok, I see. Thanks, Gui >