From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id p3T1GCDY032448 for ; Thu, 28 Apr 2011 20:16:12 -0500 Date: Fri, 29 Apr 2011 11:19:29 +1000 From: Dave Chinner Subject: Re: 2.6.39-rc3, 2.6.39-rc4: XFS lockup - regression since 2.6.38 Message-ID: <20110429011929.GA13542@dastard> References: <20110423224403.5fd1136a@neptune.home> <20110427050850.GG12436@dastard> <20110427182622.05a068a2@neptune.home> <20110428194528.GA1627@x4.trippels.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20110428194528.GA1627@x4.trippels.de> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Markus Trippelsdorf Cc: Dave Chinner , linux-kernel@vger.kernel.org, xfs@oss.sgi.com, Christoph Hellwig , xfs-masters@oss.sgi.com, Bruno =?iso-8859-1?Q?Pr=E9mont?= , Alex Elder On Thu, Apr 28, 2011 at 09:45:28PM +0200, Markus Trippelsdorf wrote: > On 2011.04.27 at 18:26 +0200, Bruno Pr=E9mont wrote: > > On Wed, 27 April 2011 Dave Chinner wrote: > > > On Sat, Apr 23, 2011 at 10:44:03PM +0200, Bruno Pr=E9mont wrote: > > > > Running 2.6.39-rc3+ and now again on 2.6.39-rc4+ (I've not tested -= rc1 > > > > or -rc2) I've hit a "dying machine" where processes writing to disk= end > > > > up in D state. > > > > From occurrence with -rc3+ I don't have logs as those never hit the= disk, > > > > for -rc4+ I have the following (sysrq+t was too big, what I have of= it > > > > misses a dozen of kernel tasks - if needed, please ask): > > > > = > > > > The -rc4 kernel is at commit 584f79046780e10cb24367a691f8c28398a00e= 84 > > > > (+ 1 patch of mine to stop disk on reboot), > > > > full dmesg available if needed; kernel config attached (only select= ed > > > > options). In case there is something I should do at next occurrence > > > > please tell. Unfortunately I have no trigger for it and it does not > > > > happen very often. > > > > = > > > > [ 0.000000] Linux version 2.6.39-rc4-00120-g73b5b55 (kbuild@nept= une) (gcc version 4.4.5 (Gentoo 4.4.5 p1.2, pie-0.4.5) ) #12 Thu Apr 21 19:= 28:45 CEST 2011 > > > > = > > > > = > > > > [32040.120055] INFO: task flush-8:0:1665 blocked for more than 120 = seconds. > > > > [32040.120068] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" d= isables this message. > > > > [32040.120077] flush-8:0 D 00000000 4908 1665 2 0x0000= 0000 > > > > [32040.120099] f55efb5c 00000046 00000000 00000000 00000000 000000= 01 e0382924 00000000 > > > > [32040.120118] f55efb0c f55efb5c 00000004 f629ba70 572f01a2 00001c= fe f629ba70 ffffffc0 > > > > [32040.120135] f55efc68 f55efb30 f889d7f8 f55efb20 00000000 f55efc= 68 e0382900 f55efc94 > > > > [32040.120153] Call Trace: > > > > [32040.120220] [] ? xfs_bmap_search_multi_extents+0x88/0= xe0 [xfs] > > > > [32040.120239] [] ? kmem_cache_alloc+0x2d/0x110 > > > > [32040.120294] [] ? xlog_space_left+0x2a/0xc0 [xfs] > > > > [32040.120346] [] xlog_wait+0x4b/0x70 [xfs] > > > > [32040.120359] [] ? try_to_wake_up+0xc0/0xc0 > > > > [32040.120411] [] xlog_grant_log_space+0x8b/0x240 [xfs] > > > > [32040.120464] [] ? xlog_grant_push_ail+0xbe/0xf0 [xfs] > > > > [32040.120516] [] xfs_log_reserve+0xab/0xb0 [xfs] > > > > [32040.120571] [] xfs_trans_reserve+0x78/0x1f0 [xfs] > > > = > > > Hmmmmm. That may be caused by the conversion of the xfsaild to a > > > work queue. Can you post the output of "xfs_info " and the > > > mount options (/proc/mounts) used on you system? > = > I may have hit the same problem today and managed to capture some sysrq-l > and sysrq-w output. = > = > The system was largely unusable during this incident. I could still > switch between X and the console (and press the sysrq key-combination), > but I couldn't run any commands in the terminal. > = > = > x4 ~ # xfs_info / > meta-data=3D/dev/root isize=3D256 agcount=3D4, agsize=3D1= 949824 blks > =3D sectsz=3D512 attr=3D2 > data =3D bsize=3D4096 blocks=3D7799296, imaxp= ct=3D25 > =3D sunit=3D128 swidth=3D128 blks > naming =3Dversion 2 bsize=3D4096 ascii-ci=3D0 > log =3Dinternal bsize=3D4096 blocks=3D3808, version= =3D2 > =3D sectsz=3D512 sunit=3D8 blks, lazy-co= unt=3D1 > realtime =3Dnone extsz=3D4096 blocks=3D0, rtextents= =3D0 OK, so the common elements here appears to be root filesystems with small log sizes, which means they are tail pushing all the time metadata operations are in progress. Definitely seems like a race in the AIL workqueue trigger mechanism. I'll see if I can reproduce this and cook up a patch to fix it. Cheers, Dave. -- = Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs