Created attachment 512869 [details]
soft lockup log

Clone for a new soft lockup, I saw the soft lockup only once for now.
Kernel version is 2.6.18-238.19.1.el5
Upload the full log

+++ This bug was initially created as a clone of Bug #650122 +++

Description of problem:
When testing xfs with xfstests, 104 causes the system hung_task_timeout. 104 cannot move on, but the system still can be used as normal.

INFO: task pdflush:16694 blocked for more than 120 seconds. 
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 
pdflush       D ffff810003347120     0 16694     43         22136 28115 (L-TLB) 
 ffff81005c457690 0000000000000046 0000000000200200 ffff810049047900 
 ffff810049047a80 000000000000000a ffff8100bcbe9820 ffff810037c02080 
 000001da8202f96d 0000000000009401 ffff8100bcbe9a08 000000023beaa500 
Call Trace: 
 [<ffffffff8006466c>] __down_read+0x7a/0x92 
 [<ffffffff88680055>] :xfs:xfs_bmap_btalloc+0x27c/0x8c1 
 [<ffffffff80046fbc>] try_to_wake_up+0x472/0x484 
 [<ffffffff8867a2ef>] :xfs:xfs_bmap_search_multi_extents+0x9d/0xda 
 [<ffffffff88680d8a>] :xfs:xfs_bmapi+0x6eb/0xe79 
 [<ffffffff886a1bae>] :xfs:xfs_log_reserve+0xad/0xc9 
 [<ffffffff8869d104>] :xfs:xfs_iomap_write_allocate+0x201/0x328 
 [<ffffffff8869db49>] :xfs:xfs_iomap+0x22a/0x2a5 
 [<ffffffff886b270a>] :xfs:xfs_map_blocks+0x2d/0x63 
 [<ffffffff886b334a>] :xfs:xfs_page_state_convert+0x2af/0x544 
 [<ffffffff886b372b>] :xfs:xfs_vm_writepage+0xa7/0xe0 
 [<ffffffff8001d0e6>] mpage_writepages+0x1bf/0x37d 
 [<ffffffff886b3684>] :xfs:xfs_vm_writepage+0x0/0xe0 
 [<ffffffff8008cf69>] find_busiest_group+0x20d/0x621 
 [<ffffffff8005ac3b>] do_writepages+0x20/0x2f 
 [<ffffffff8002fc91>] __writeback_single_inode+0x19e/0x318 
 [<ffffffff80021039>] sync_sb_inodes+0x1b5/0x26f 
 [<ffffffff800a267e>] keventd_create_kthread+0x0/0xc4 
 [<ffffffff80051143>] writeback_inodes+0x82/0xd8 
 [<ffffffff800cbb57>] wb_kupdate+0xd4/0x14e 
 [<ffffffff8005662e>] pdflush+0x0/0x1fb 
 [<ffffffff8005677f>] pdflush+0x151/0x1fb 
 [<ffffffff800cba83>] wb_kupdate+0x0/0x14e 
 [<ffffffff80032968>] kthread+0xfe/0x132 
 [<ffffffff8005dfb1>] child_rip+0xa/0x11 
 [<ffffffff800a267e>] keventd_create_kthread+0x0/0xc4 
 [<ffffffff800e4629>] generic_write_end+0x0/0x58 
 [<ffffffff886b1f04>] :xfs:xfs_vm_write_begin+0x0/0x1e 
 [<ffffffff8003286a>] kthread+0x0/0x132 
 [<ffffffff8005dfa7>] child_rip+0x0/0x11 
 
INFO: task fsstress:22324 blocked for more than 120 seconds. 
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 
fsstress      D 0000000000000001     0 22324  22322         22325       (NOTLB) 
 ffff81001adfba98 0000000000000082 ffff810086381698 ffffffff886a070c 
 ffff81002e1efa98 0000000000000007 ffff8100088770c0 ffff8100ba9da820 
 000001d360dd41e8 000000000000da95 ffff8100088772a8 000000004f8efca8 
Call Trace: 
 [<ffffffff886a070c>] :xfs:xlog_state_get_iclog_space+0x31/0x221 
 [<ffffffff8006381f>] schedule_timeout+0x1e/0xad 
 [<ffffffff8006466c>] __down_read+0x7a/0x92 
 [<ffffffff8869432e>] :xfs:xfs_ialloc_ag_select+0xc8/0x271 
 [<ffffffff886a1712>] :xfs:_xfs_log_force+0x63/0x68 
 [<ffffffff8869450a>] :xfs:xfs_dialloc+0x33/0x809 
 [<ffffffff886b1d31>] :xfs:kmem_zone_zalloc+0x1e/0x2f 
 [<ffffffff886a1adc>] :xfs:xlog_ticket_get+0xc1/0xe6 
 [<ffffffff8869ab79>] :xfs:xfs_ialloc+0x5f/0x57f 
 [<ffffffff886ac6cb>] :xfs:xfs_dir_ialloc+0x86/0x2b7 
 [<ffffffff886a1074>] :xfs:xlog_grant_log_space+0x204/0x25c 
 [<ffffffff886af198>] :xfs:xfs_create+0x237/0x45c 
 [<ffffffff88674d4f>] :xfs:xfs_attr_get+0x8e/0x9f 
 [<ffffffff886b8ab4>] :xfs:xfs_vn_mknod+0x144/0x215 
 [<ffffffff800ea838>] vfs_mknod+0x105/0x176 
 [<ffffffff800ead25>] sys_mknodat+0x144/0x188 
 [<ffffffff8005d229>] tracesys+0x71/0xe0 
 [<ffffffff8005d28d>] tracesys+0xd5/0xe0 

Job link:
https://beaker.engineering.redhat.com/recipes/57248

Console log:
https://beaker.engineering.redhat.com/logs/2010/11/287/28779/57248///console.log

Version-Release number of selected component (if applicable):
RHEL5.6-Server-20101029.0
kernel 2.6.18-230.el5

How reproducible:
I do made this happen several times.

Steps to Reproduce:
1.
2.
3.
  
Actual results:
104 hung there and average load of the system is high.

Expected results:
104 passed with a sane system.

Additional info:

--- Additional comment from yugzhang on 2010-11-11 03:22:11 EST ---

Clarify more about this bug:
I use xfstests from /kernel/filesystems/xfs/xfstests to test xfs automatically in beaker.
By viewing the logs, I saw this problem once. 
But I couldn't reproduce it manually.

How reproducible:
Rarely

Steps to Reproduce:
1.Install and configure xfstests(see README under xfstests directory)
2../check 104
3.

--- Additional comment from yugzhang on 2010-11-11 03:41:01 EST ---

More attempts. Now I could catch this ocassionally when testing manually.

--- Additional comment from esandeen on 2010-11-11 11:47:02 EST ---

There's a fix for this upstream, it's a known problem (thanks Christoph) and we'll have to decide how critical it is for RHEL5.6 I think.

--- Additional comment from dchinner on 2010-11-14 23:21:03 EST ---

It is not exactly a simple fix - it touches a lot of code because it changes the way we access the perag structures. However, this deadlock is actually a very rare problem in the real world so I'd be inclined to ignore it until there is a real need to fix it.

Cheers,

Dave.