On Tue, Dec 03, 2013 at 11:50:57PM +1100, Dave Chinner wrote: > On Tue, Dec 03, 2013 at 10:53:58AM +0100, Emmanuel Lacour wrote: > > On Thu, Nov 28, 2013 at 09:05:21PM +1100, Dave Chinner wrote: > > > On Thu, Nov 28, 2013 at 10:13:22AM +0100, Emmanuel Lacour wrote: > > > > > > > > Dear XFS users, > > > > > > > > > > > > I run a Ceph cluster using XFS on Debian wheezy servers and Linux 3.10 > > > > (debian backports). I see the following line in our logs: > > > > > > > > XFS: possible memory allocation deadlock in kmem_alloc (mode:0x250) > > > > > > > > does this reveal a problem in my setup or may I ignore it? If it's a > > > > problem, can someone give me any hint on solving this? > > > > > > It might be, but you need to provide more information for us to be > > > able to make any intelligent comment on the message. Start here: > > > > > > http://xfs.org/index.php/XFS_FAQ#Q:_What_information_should_I_include_when_reporting_a_problem.3F > > > > > > > > > The problem continue and crashed my ceph cluster again, so here is all > > the informations said in the FAQ: > > > > http://people.easter-eggs.org/~manu/xfs.log > > OK, 32GB RAM, no obvious shortage, no dirty or writeback data. > 2TB SATA drives, 32AGs, only unusual setting is 64k directory block > size. > > Yup, there's your problem: > > [4583991.478469] ceph-osd D ffff88047fc93f40 0 22951 > 1 0x00000004 > [4583991.478471] ffff88046d241140 0000000000000082 ffffffff81047e75 > ffff88046f949800 > [4583991.478475] 0000000000013f40 ffff88039eb0bfd8 ffff88039eb0bfd8 > ffff88046d241140 > [4583991.478479] 0000000000000000 00000001444d68bd ffff88046d241140 > 0000000000000005 > [4583991.478483] Call Trace: > [4583991.478487] [<ffffffff81047e75>] ? internal_add_timer+0xd/0x28 > [4583991.478491] [<ffffffff8138e34a>] ? schedule_timeout+0xeb/0x123 > [4583991.478494] [<ffffffff81047e63>] ? ftrace_raw_event_timer_class+0x9d/0x9d > [4583991.478498] [<ffffffff8138edb6>] ? io_schedule_timeout+0x60/0x86 > [4583991.478502] [<ffffffff810d85ad>] ? congestion_wait+0x70/0xdb > [4583991.478505] [<ffffffff8105858f>] ? abort_exclusive_wait+0x79/0x79 > [4583991.478518] [<ffffffffa056e3f9>] ? kmem_alloc+0x65/0x6f [xfs] > [4583991.478535] [<ffffffffa0592c4a>] ? xfs_dir2_block_to_sf+0x5b/0x1fb [xfs] > [4583991.478550] [<ffffffffa0592be0>] ? xfs_dir2_block_sfsize+0x15b/0x16a [xfs] > [4583991.478566] [<ffffffffa058bf9a>] ? xfs_dir2_block_removename+0x1c7/0x208 [xfs] > [4583991.478581] [<ffffffffa058ab4a>] ? xfs_dir_removename+0xda/0x114 [xfs] > [4583991.478594] [<ffffffffa056a55c>] ? xfs_rename+0x428/0x554 [xfs] > [4583991.478606] [<ffffffffa0567321>] ? xfs_vn_rename+0x5e/0x65 [xfs] > [4583991.478610] [<ffffffff8111677b>] ? vfs_rename+0x224/0x35f > [4583991.478614] [<ffffffff81113d0b>] ? lookup_dcache+0x22/0x95 > [4583991.478618] [<ffffffff81116a7e>] ? SYSC_renameat+0x1c8/0x257 > [4583991.478622] [<ffffffff810fb0fd>] ? __cache_free.isra.45+0x178/0x187 > [4583991.478625] [<ffffffff81117eb1>] ? SyS_mkdirat+0x2e/0xce > [4583991.478629] [<ffffffff8100d56a>] ? do_notify_resume+0x53/0x68 > [4583991.478633] [<ffffffff81395429>] ? system_call_fastpath+0x16/0x1b > > It'll be stuck on this: > > hdr = kmem_alloc(mp->m_dirblksize, KM_SLEEP); > > which is trying to allocate a contiguous 64k buffer to copy the > direct contents into before freeing the block and then formatting > them into the inode. The failure will be caused by memory > fragmentation, and the only way around it is to avoid the contiguous > allocation of that size. > > Which, I think, is pretty easy to do. Yup, barely smoke tested patch > below that demonstrates the fix. Beware - patch may eat babies and > ask for more. Use it at your own risk! > > I'll post it for review once it's had some testing and I know it > doesn't corrupt directories all over the place. > > > This may be related to a friend problem here: > > > > http://tracker.ceph.com/issues/6386 > > Doesn't look related, unless the OOM killer is being triggered > somehow... > > Hmmmm - there's also a good chance the the transaction commit code > has this same problem contiguous allocation problem given that it > has to allocate enough space to log an entire directory buffer. Good > guess - there's another thread stuck on exactly that: > > [4583991.476833] ceph-osd D ffff88047fc33f40 0 11072 1 0x00000004 > [4583991.476836] ffff88038b32a040 0000000000000082 ffffffff81047e75 ffff88046f946040 > [4583991.476840] 0000000000013f40 ffff88048ea11fd8 ffff88048ea11fd8 ffff88038b32a040 > [4583991.476844] 0000000000000000 00000001444d68be ffff88038b32a040 0000000000000005 > [4583991.476848] Call Trace: > [4583991.476852] [<ffffffff81047e75>] ? internal_add_timer+0xd/0x28 > [4583991.476855] [<ffffffff8138e34a>] ? schedule_timeout+0xeb/0x123 > [4583991.476859] [<ffffffff81047e63>] ? ftrace_raw_event_timer_class+0x9d/0x9d > [4583991.476862] [<ffffffff8138edb6>] ? io_schedule_timeout+0x60/0x86 > [4583991.476867] [<ffffffff810d85ad>] ? congestion_wait+0x70/0xdb > [4583991.476870] [<ffffffff8105858f>] ? abort_exclusive_wait+0x79/0x79 > [4583991.476883] [<ffffffffa056e3f9>] ? kmem_alloc+0x65/0x6f [xfs] > [4583991.476899] [<ffffffffa05a77a6>] ? xfs_log_commit_cil+0xe8/0x3d1 [xfs] > [4583991.476904] [<ffffffff810748ab>] ? current_kernel_time+0x9/0x30 > [4583991.476909] [<ffffffff81041942>] ? current_fs_time+0x27/0x2d > [4583991.476925] [<ffffffffa05a3b7b>] ? xfs_trans_commit+0x62/0x1cf [xfs] > [4583991.476939] [<ffffffffa056d3ad>] ? xfs_create+0x41e/0x54f [xfs] > [4583991.476943] [<ffffffff81114574>] ? lookup_fast+0x3d/0x215 > [4583991.476954] [<ffffffffa056cf29>] ? xfs_lookup+0x88/0xee [xfs] > [4583991.476966] [<ffffffffa0567428>] ? xfs_vn_mknod+0xb7/0x162 [xfs] > [4583991.476970] [<ffffffff81115fda>] ? vfs_create+0x62/0x8b > [4583991.476974] [<ffffffff81113d0b>] ? lookup_dcache+0x22/0x95 > [4583991.476978] [<ffffffff81117179>] ? do_last+0x595/0xa16 > [4583991.476982] [<ffffffff811176be>] ? path_openat+0xc4/0x335 > [4583991.476985] [<ffffffff81117bda>] ? do_filp_open+0x2a/0x6e > [4583991.476989] [<ffffffff81120b62>] ? __alloc_fd+0xd0/0xe1 > [4583991.476993] [<ffffffff8110b684>] ? do_sys_open+0x5c/0xe0 > [4583991.476996] [<ffffffff81395429>] ? system_call_fastpath+0x16/0x1b > > That one isn't so easy to fix, unfortunately. > > Cheers, > > Dave. > -- > Dave Chinner > david@xxxxxxxxxxxxx > > xfs: xfs_dir2_block_to_sf temp buffer allocation fails > > From: Dave Chinner <dchinner@xxxxxxxxxx> > > If we are using a large directory block size, and memory becomes > fragmented, we can get memory allocation failures trying to > kmem_alloc(64k) for a temporary buffer. However, there is not need > for a directory buffer sized allocation, as the end result ends up > in the inode literal area. This is, at most, slightly less than 2k > of space, and hence we don't need an allocation larger than that > fora temporary buffer. > > Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx> D'oh, I missed this one too. If you stick 'patch' in the subject they'll have additional visibility. Looks good to me. Reviewed-by: Ben Myers <bpm@xxxxxxx> _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
