Found Bug: soft lockup - CPU #2 stuck for 61s! [kswapd0:75] on console.

Ubuntu 10.10
8 core machine with 16 GB RAM, Intel board with (2) 4 core Xeon's. RAID 6 array with 6 disks in software RAID (mdraid)

After large copy job to vbox virutal machine on this host found this on console:

Swap space is on RAID 6 array.

"[314082.372497] Bug: soft lockup - CPU #2 stuck for 61s! [kswapd0: 75]"
followed by some hex code.

This error was preceded by several errors like this:

Info: task kdmflush: 572 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this
 message.

Info: task jbd2/md2-8:589 blocked for more than 120 seconds.
Info: task flush-9:2:639 blocked for more than 120 seconds.
Info: task jbd2/dm-0-8:1371 blocked for more than 120 seconds.
Info: task rsyslogd:7393 blocked for more than 120 seconds.
Info: task master:1569 blocked for more than 120 seconds.

The machine was not locked up and I have not yet attempted a reboot but this is very concerning.

Here's the soft lockup error from dmesg:

[314082.372497] BUG: soft lockup - CPU#2 stuck for 61s! [kswapd0:75]
[314082.372550] Modules linked in: vboxnetadp vboxnetflt vboxdrv lp ioatdma parp
ort joydev i7core_edac hed edac_core raid10 raid456 async_pq async_xor xor async
_memcpy async_raid6_recov usbhid hid igb dca raid6_pq async_tx raid1 raid0 multi
path linear
[314082.372576] CPU 2
[314082.372578] Modules linked in: vboxnetadp vboxnetflt vboxdrv lp ioatdma parp
ort joydev i7core_edac hed edac_core raid10 raid456 async_pq async_xor xor async
_memcpy async_raid6_recov usbhid hid igb dca raid6_pq async_tx raid1 raid0 multi
path linear
[314082.372605]
[314082.372609] Pid: 75, comm: kswapd0 Not tainted 2.6.35-28-server #49-Ubuntu S
5520HC/S5520HC
[314082.372612] RIP: 0010:[<ffffffff81118f70>] [<ffffffff81118f70>] zone_nr_fre
e_pages+0x0/0xc0
[314082.372620] RSP: 0018:ffff880265dade08 EFLAGS: 00000282
[314082.372624] RAX: 0000000000000020 RBX: ffff880265dade40 RCX: 000000000000000
0
[314082.372627] RDX: 0000000000000895 RSI: 0000000000000000 RDI: ffff880100000e0
0
[314082.372631] RBP: ffffffff8100aa8e R08: 0000000000000000 R09: 000000000000010
0
[314082.372634] R10: 0000000000000000 R11: 0000000000000003 R12: 000000000000000
0
[314082.372637] R13: ffff880265dade04 R14: ffff8802668144d0 R15: ffff880265daddb
0
[314082.372642] FS: 0000000000000000(0000) GS:ffff880001e20000(0000) knlGS:0000
000000000000
[314082.372646] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[314082.372649] CR2: 0000000001e003c0 CR3: 0000000001a2a000 CR4: 00000000000026e
0
[314082.372652] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 000000000000000
0
[314082.372656] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 000000000000040
0
[314082.372660] Process kswapd0 (pid: 75, threadinfo ffff880265dac000, task ffff
8802668144d0)
[314082.372662] Stack:
[314082.372700] ffffffff8110700a ffff880265dade40 ffff880100000000 000000000000
0002
[314082.372705] <0> ffff8802668144d0 ffff880265dade70 ffff8801000040a8 ffff88026
5dadee0
[314082.372711] <0> ffffffff81111f6c ffff880265dadfd8 0000000000000000 000000006
5dadfd8
[314082.372717] Call Trace:
[314082.372760] [<ffffffff8110700a>] ? zone_watermark_ok+0x2a/0xf0
[314082.372765] [<ffffffff81111f6c>] ? kswapd+0x25c/0x300
[314082.372770] [<ffffffff8107fb10>] ? autoremove_wake_function+0x0/0x40
[314082.372775] [<ffffffff81111d10>] ? kswapd+0x0/0x300
[314082.372780] [<ffffffff8107f596>] ? kthread+0x96/0xa0
[314082.372785] [<ffffffff8100aee4>] ? kernel_thread_helper+0x4/0x10
[314082.372790] [<ffffffff8107f500>] ? kthread+0x0/0xa0
[314082.372794] [<ffffffff8100aee0>] ? kernel_thread_helper+0x0/0x10
[314082.372797] Code: 48 89 c2 e8 13 36 fe ff 89 df e8 6c e5 fd ff 48 8b 5d d8 4
c 8b 65 e0 4c 8b 6d e8 4c 8b 75 f0 4c 8b 7d f8 c9 c3 90 90 90 90 90 90 <55> 48 8
9 e5 48 83 ec 20 48 89 5d e8 4c 89 65 f0 4c 89 6d f8 0f
[314082.373196] Call Trace:
[314082.373201] [<ffffffff8110700a>] ? zone_watermark_ok+0x2a/0xf0
[314082.373205] [<ffffffff81111f6c>] ? kswapd+0x25c/0x300
[314082.373210] [<ffffffff8107fb10>] ? autoremove_wake_function+0x0/0x40
[314082.373215] [<ffffffff81111d10>] ? kswapd+0x0/0x300
[314082.373219] [<ffffffff8107f596>] ? kthread+0x96/0xa0
[314082.373224] [<ffffffff8100aee4>] ? kernel_thread_helper+0x4/0x10
[314082.373229] [<ffffffff8107f500>] ? kthread+0x0/0xa0
[314082.373234] [<ffffffff8100aee0>] ? kernel_thread_helper+0x0/0x10