Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756313Ab0F2O4a (ORCPT ); Tue, 29 Jun 2010 10:56:30 -0400 Received: from mx1.redhat.com ([209.132.183.28]:9388 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756274Ab0F2O40 (ORCPT ); Tue, 29 Jun 2010 10:56:26 -0400 From: Jeff Moyer To: Tao Ma Cc: axboe@kernel.dk, vgoyal@redhat.com, linux-kernel@vger.kernel.org, linux-ext4@vger.kernel.org, Joel Becker , Sunil Mushran , "ocfs2-devel\@oss.oracle.com" Subject: Re: [PATCH 0/3 v5][RFC] ext3/4: enhance fsync performance when using CFQ References: <1277242502-9047-1-git-send-email-jmoyer@redhat.com> <4C21D442.8080703@oracle.com> <4C22F316.3080009@oracle.com> <4C284419.3000905@oracle.com> X-PGP-KeyID: 1F78E1B4 X-PGP-CertKey: F6FE 280D 8293 F72C 65FD 5A58 1FF8 A7CA 1F78 E1B4 X-PCLoadLetter: What the f**k does that mean? Date: Tue, 29 Jun 2010 10:56:15 -0400 In-Reply-To: <4C284419.3000905@oracle.com> (Tao Ma's message of "Mon, 28 Jun 2010 14:41:29 +0800") Message-ID: User-Agent: Gnus/5.110011 (No Gnus v0.11) Emacs/23.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2491 Lines: 55 Tao Ma writes: > Hi Jeff, > > On 06/27/2010 09:48 PM, Jeff Moyer wrote: >> Tao Ma writes: >>> I am sorry to say that the patch make jbd2 locked up when I tested >>> fs_mark using ocfs2. >>> I have attached the log from my netconsole server. After I reverted >>> the patch [3/3], the box works again. >> >> I can't reproduce this, unfortunately. Also, when building with the >> .config you sent me, the disassembly doesn't line up with the stack >> trace you posted. >> >> I'm not sure why yielding the queue would cause a deadlock. The only >> explanation I can come up with is that I/O is not being issued. I'm >> assuming that no other I/O will be completed to the file system in >> question. Is that right? Could you send along the output from sysrq-t? > yes, I just mounted it and begin the test, so there should be no > outstanding I/O. So do you need me to setup another disk for test? > I have attached the sysrq output in sysrq.log. please check. Well, if it doesn't take long to reproduce, then it might be helpful to see a blktrace of the run. However, it might also just be worth waiting for the next version of the patch to see if that fixes your issue. > btw, I also met with a NULL pointer deference in cfq_yield. I have > attached the null.log also. This seems to be related to the previous > deadlock and happens when I try to remount the same volume after > reboot and ocfs2 try to do some recovery. Pid: 4130, comm: ocfs2_wq Not tainted 2.6.35-rc3+ #5 0MM599/OptiPlex 745 RIP: 0010:[] [] cfq_yield+0x5f/0x135 RSP: 0018:ffff880123061c60 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff88012c2b5ea8 RCX: ffff88012c3a30d0 ffffffff82161528: e8 69 eb ff ff callq ffffffff82160096 ffffffff8216152d: 49 89 c6 mov %rax,%r14 ffffffff82161530: 48 8b 85 00 06 00 00 mov 0x600(%rbp),%rax ffffffff82161537: f0 48 ff 00 lock incq (%rax) I'm pretty sure that's a NULL pointer deref of the tsk->iocontext that was passed into the yield function. I've since fixed that, so your recovery code should be safe in the newest version (which I've not yet posted). Cheers, Jeff -- 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/