oops

久々にoopsが出たので貼り付け。
多分下のコマンド実行中でのoops発生と思う。
sudo dd if=/dev/zero of=/dev/sdf bs=1M

[287041.483833] INFO: task hald-addon-stor:19153 blocked for more than 120 seconds.
[287041.483841] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[287041.483846] hald-addon-st D ffff880056608e28     0 19153   3549 0x00000000
[287041.483860] __ratelimit: 374 callbacks suppressed
[287041.483865] BUG: using smp_processor_id() in preemptible [00000000] code: khungtaskd/262
[287041.483875] caller is show_stack_log_lvl+0x3c/0x133
[287041.483881] Pid: 262, comm: khungtaskd Not tainted 2.6.31-rc9-x86tip-tip #1
[287041.483886] Call Trace:
[287041.483899]  [<ffffffff8123ed44>] debug_smp_processor_id+0xe0/0x114
[287041.483906]  [<ffffffff81016b1e>] show_stack_log_lvl+0x3c/0x133
[287041.483913]  [<ffffffff810181d9>] show_stack+0x2f/0x45
[287041.483923]  [<ffffffff8105ccbd>] sched_show_task+0xc6/0xe1
[287041.483931]  [<ffffffff810deecb>] watchdog+0x213/0x295
[287041.483937]  [<ffffffff810ded32>] ? watchdog+0x7a/0x295
[287041.483943]  [<ffffffff810decb8>] ? watchdog+0x0/0x295
[287041.483951]  [<ffffffff81095705>] kthread+0x9d/0xa5
[287041.483958]  [<ffffffff8101439a>] child_rip+0xa/0x20
[287041.483967]  [<ffffffff81013cd4>] ? restore_args+0x0/0x30
[287041.483974]  [<ffffffff81095668>] ? kthread+0x0/0xa5
[287041.483980]  [<ffffffff81014390>] ? child_rip+0x0/0x20
[287041.483984]  ffff88005991db88 0000000000000086 ffff88005991dad8 ffffffff810a97ad
[287041.484065]  00000000810d092a 0000000000000000 ffff88005991c000 0000000000011b40
[287041.484096]  ffff88005991dfd8 ffff88004dc6bcf0 ffff8800b48b6590 ffff88004dc6c008
[287041.484120] Call Trace:
[287041.484133]  [<ffffffff810a97ad>] ? put_lock_stats+0x3b/0x5a
[287041.484147]  [<ffffffff813d36a4>] ? __mutex_lock_common+0x2ac/0x4ce
[287041.484157]  [<ffffffff810ab703>] ? trace_hardirqs_on_caller+0x123/0x15e
[287041.484167]  [<ffffffff813d36d7>] __mutex_lock_common+0x2df/0x4ce
[287041.484179]  [<ffffffff81192138>] ? __blkdev_get+0x91/0x385
[287041.484190]  [<ffffffff81192138>] ? __blkdev_get+0x91/0x385
[287041.484201]  [<ffffffff813d39db>] mutex_lock_nested+0x4a/0x67
[287041.484210]  [<ffffffff81192138>] __blkdev_get+0x91/0x385
[287041.484221]  [<ffffffff8119244f>] blkdev_get+0x23/0x39
[287041.484231]  [<ffffffff811924ea>] blkdev_open+0x85/0xd1
[287041.484244]  [<ffffffff811559f6>] __dentry_open+0x224/0x368
[287041.484254]  [<ffffffff81192465>] ? blkdev_open+0x0/0xd1
[287041.484266]  [<ffffffff81167846>] ? inode_permission+0xb2/0xd5
[287041.484276]  [<ffffffff81155c48>] nameidata_to_filp+0x55/0x7d
[287041.484288]  [<ffffffff8116a0b5>] do_filp_open+0x536/0xa40
[287041.484298]  [<ffffffff810a97ad>] ? put_lock_stats+0x3b/0x5a
[287041.484310]  [<ffffffff810a9891>] ? lock_release_holdtime+0xc5/0xe1
[287041.484321]  [<ffffffff813d5058>] ? _spin_unlock+0x5e/0x82
[287041.484332]  [<ffffffff8117817e>] ? alloc_fd+0x131/0x156
[287041.484345]  [<ffffffff81155653>] do_sys_open+0x70/0x12e
[287041.484357]  [<ffffffff8115577e>] sys_open+0x33/0x49
[287041.484368]  [<ffffffff81013172>] system_call_fastpath+0x16/0x1b
[287041.484377] 1 lock held by hald-addon-stor/19153:
[287041.484384]  #0:  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff81192138>] __blkdev_get+0x91/0x385
[287041.484412] INFO: task hald-probe-stor:19231 blocked for more than 120 seconds.
[287041.484418] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[287041.484425] hald-probe-st D ffff880056608e28     0 19231   3549 0x00000004
[287041.484443] BUG: using smp_processor_id() in preemptible [00000000] code: khungtaskd/262
[287041.484451] caller is show_stack_log_lvl+0x3c/0x133
[287041.484457] Pid: 262, comm: khungtaskd Not tainted 2.6.31-rc9-x86tip-tip #1
[287041.484464] Call Trace:
[287041.484474]  [<ffffffff8123ed44>] debug_smp_processor_id+0xe0/0x114
[287041.484485]  [<ffffffff81016b1e>] show_stack_log_lvl+0x3c/0x133
[287041.484496]  [<ffffffff810181d9>] show_stack+0x2f/0x45
[287041.484507]  [<ffffffff8105ccbd>] sched_show_task+0xc6/0xe1
[287041.484517]  [<ffffffff810deecb>] watchdog+0x213/0x295
[287041.484527]  [<ffffffff810ded32>] ? watchdog+0x7a/0x295
[287041.484537]  [<ffffffff810decb8>] ? watchdog+0x0/0x295
[287041.484547]  [<ffffffff81095705>] kthread+0x9d/0xa5
[287041.484560]  [<ffffffff8101439a>] child_rip+0xa/0x20
[287041.484571]  [<ffffffff81013cd4>] ? restore_args+0x0/0x30
[287041.484580]  [<ffffffff81095668>] ? kthread+0x0/0xa5
[287041.484592]  [<ffffffff81014390>] ? child_rip+0x0/0x20
[287041.484598]  ffff8800aed15b88 0000000000000086 ffff8800aed15ad8 ffffffff810a97ad
[287041.484623]  0000000030c9018c 0000000000000000 ffff8800aed14000 0000000000011b40
[287041.484648]  ffff8800aed15fd8 ffff8800b2155140 ffff8800b2150000 ffff8800b2155458
[287041.484673] Call Trace:
[287041.484683]  [<ffffffff810a97ad>] ? put_lock_stats+0x3b/0x5a
[287041.484694]  [<ffffffff813d36a4>] ? __mutex_lock_common+0x2ac/0x4ce
[287041.484703]  [<ffffffff810ab703>] ? trace_hardirqs_on_caller+0x123/0x15e
[287041.484715]  [<ffffffff813d36d7>] __mutex_lock_common+0x2df/0x4ce
[287041.484724]  [<ffffffff81192138>] ? __blkdev_get+0x91/0x385
[287041.484735]  [<ffffffff81192138>] ? __blkdev_get+0x91/0x385
[287041.484746]  [<ffffffff813d39db>] mutex_lock_nested+0x4a/0x67
[287041.484757]  [<ffffffff81192138>] __blkdev_get+0x91/0x385
[287041.484769]  [<ffffffff8119244f>] blkdev_get+0x23/0x39
[287041.484780]  [<ffffffff811924ea>] blkdev_open+0x85/0xd1
[287041.484791]  [<ffffffff811559f6>] __dentry_open+0x224/0x368
[287041.484801]  [<ffffffff81192465>] ? blkdev_open+0x0/0xd1
[287041.484812]  [<ffffffff81167846>] ? inode_permission+0xb2/0xd5
[287041.484824]  [<ffffffff81155c48>] nameidata_to_filp+0x55/0x7d
[287041.484834]  [<ffffffff8116a0b5>] do_filp_open+0x536/0xa40
[287041.484844]  [<ffffffff810a97ad>] ? put_lock_stats+0x3b/0x5a
[287041.484855]  [<ffffffff810a9891>] ? lock_release_holdtime+0xc5/0xe1
[287041.484868]  [<ffffffff813d5058>] ? _spin_unlock+0x5e/0x82
[287041.484877]  [<ffffffff8117817e>] ? alloc_fd+0x131/0x156
[287041.484888]  [<ffffffff81155653>] do_sys_open+0x70/0x12e
[287041.484900]  [<ffffffff8115577e>] sys_open+0x33/0x49
[287041.484910]  [<ffffffff81013172>] system_call_fastpath+0x16/0x1b
[287041.484918] 1 lock held by hald-probe-stor/19231:
[287041.484924]  #0:  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff81192138>] __blkdev_get+0x91/0x385

2009/09/10追記
プロセスのハングアップを検知してメッセージを出してるのはhung_task.c、
http://lxr.linux.no/#linux+v2.6.31/kernel/hung_task.c
この中のcheck_hung_task()で以下のメッセージを出す(その他のも)。

[287041.483833] INFO: task hald-addon-stor:19153 blocked for more than 120 seconds.
[287041.483841] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

ちょうどこの部分。

  92        /*
  93         * Ok, the task did not get scheduled for more than 2 minutes,
  94         * complain:
  95         */
  96        printk(KERN_ERR "INFO: task %s:%d blocked for more than "
  97                        "%ld seconds.\n", t->comm, t->pid, timeout);
  98        printk(KERN_ERR "\"echo 0 > /proc/sys/kernel/hung_task_timeout_secs\""
  99                        " disables this message.\n");
 100        sched_show_task(t);
 101        __debug_show_held_locks(t);
 102