Comment 18 for bug 494476

Hi!

Last night the backup was interrupted again.
Our backup process timed out while waiting to be scheduled:

[71881.750043] INFO: task mbuffer:8637 blocked for more than 120 seconds.
[71881.750531] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[71881.751090] mbuffer1 D 0000000000000000 0 8637 4348 0x00000000
[71881.751094] ffff8801ef339c18 0000000000000086 0000000000015bc0 0000000000015bc0
[71881.751098] ffff880405c231a0 ffff8801ef339fd8 0000000000015bc0 ffff880405c22de0
[71881.751101] 0000000000015bc0 ffff8801ef339fd8 0000000000015bc0 ffff880405c231a0
[71881.751104] Call Trace:
[71881.751115] [<ffffffff81558e2d>] schedule_timeout+0x22d/0x300
[71881.751120] [<ffffffff812b5377>] ? kobject_put+0x27/0x60
[71881.751123] [<ffffffff8155a985>] ? _spin_lock_irq+0x15/0x20
[71881.751128] [<ffffffff8138b63a>] ? scsi_request_fn+0xda/0x5e0
[71881.751131] [<ffffffff815580d6>] wait_for_common+0xd6/0x180
[...]

This was with »cfq«. This happened at about 80% backup done.
I switch back to »noop« and report again.

Lars

PS: We have no snapshots. There is no lvm device at all on this system. (only SW-RAID6)