I experienced a full system lockup with a similar error in syslog.  My system runs 10.10 on an AMD board w/ 1x quad-core, 8GB RAM.  Kernel: 2.6.35-28-generic.  There is a md RAID 1 among other single drives.  kern.log and syslog excerpts below.

kern.log (less part identical to syslog):

May  3 14:42:18 theFourthTower kernel: [1642564.161333] INFO: task Xorg:1433 blocked for more than 120 seconds.
May  3 14:42:18 theFourthTower kernel: [1642564.161341] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
May  3 14:42:18 theFourthTower kernel: [1642564.161348] Xorg          D 0000000109c92f32     0  1433   1364 0x00400004
May  3 14:42:18 theFourthTower kernel: [1642564.161360]  ffff880204ba3758 0000000000000086 ffff880200000000 0000000000015980
May  3 14:42:18 theFourthTower kernel: [1642564.161370]  ffff880204ba3fd8 0000000000015980 ffff880204ba3fd8 ffff880204ba8000
May  3 14:42:18 theFourthTower kernel: [1642564.161379]  0000000000015980 0000000000015980 ffff880204ba3fd8 0000000000015980


syslog:

May  3 14:38:43 theFourthTower kernel: [1642349.323750] BUG: soft lockup - CPU#3 stuck for 61s! [kswapd0:76]
May  3 14:38:43 theFourthTower kernel: [1642349.323750] Modules linked in: ufs qnx4 hfsplus hfs minix ntfs vfat msdos fat jfs xfs ex
portfs reiserfs usb_storage xt_multiport binfmt_misc vboxnetadp vboxnetflt ipt_MASQUERADE xt_state ipt_REJECT xt_tcpudp iptable_filt
er nf_nat_h323 nf_conntrack_h323 nf_nat_pptp nf_conntrack_pptp nf_conntrack_proto_gre nf_nat_proto_gre nf_nat_tftp nf_conntrack_tftp
 nf_nat_sip nf_conntrack_sip nf_nat_irc nf_conntrack_irc nf_nat_ftp nf_conntrack_ftp iptable_nat nf_nat nf_conntrack_ipv4 nf_conntra
ck nf_defrag_ipv4 ip_tables x_tables vboxdrv snd_hda_codec_atihdmi snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_p
cm snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq fglrx(P) snd_timer snd_seq_device ppdev parport_pc snd it87 hwmon_vid k10temp
 i2c_piix4 edac_core edac_mce_amd soundcore snd_page_alloc shpchp lp parport raid10 raid456 async_pq async_xor xor async_memcpy asyn
c_raid6_recov usbhid hid raid6_pq async_tx raid1 raid0 multipath linear btrfs zlib_deflate 8139too floppy crc32
May  3 14:38:43 theFourthTower kernel: c 8139cp libcrc32c firewire_ohci firewire_core r8169 crc_itu_t ahci pata_atiixp libahci mii
May  3 14:38:43 theFourthTower kernel: [1642349.323750] CPU 3 
May  3 14:38:43 theFourthTower kernel: [1642349.323750] Modules linked in: ufs qnx4 hfsplus hfs minix ntfs vfat msdos fat jfs xfs ex
portfs reiserfs usb_storage xt_multiport binfmt_misc vboxnetadp vboxnetflt ipt_MASQUERADE xt_state ipt_REJECT xt_tcpudp iptable_filt
er nf_nat_h323 nf_conntrack_h323 nf_nat_pptp nf_conntrack_pptp nf_conntrack_proto_gre nf_nat_proto_gre nf_nat_tftp nf_conntrack_tftp
 nf_nat_sip nf_conntrack_sip nf_nat_irc nf_conntrack_irc nf_nat_ftp nf_conntrack_ftp iptable_nat nf_nat nf_conntrack_ipv4 nf_conntra
ck nf_defrag_ipv4 ip_tables x_tables vboxdrv snd_hda_codec_atihdmi snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_p
cm snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq fglrx(P) snd_timer snd_seq_device ppdev parport_pc snd it87 hwmon_vid k10temp
 i2c_piix4 edac_core edac_mce_amd soundcore snd_page_alloc shpchp lp parport raid10 raid456 async_pq async_xor xor async_memcpy asyn
c_raid6_recov usbhid hid raid6_pq async_tx raid1 raid0 multipath linear btrfs zlib_deflate 8139too floppy crc32
May  3 14:38:43 theFourthTower kernel: c 8139cp libcrc32c firewire_ohci firewire_core r8169 crc_itu_t ahci pata_atiixp libahci mii
May  3 14:38:43 theFourthTower kernel: [1642349.323750] 
May  3 14:38:43 theFourthTower kernel: [1642349.323750] Pid: 76, comm: kswapd0 Tainted: P            2.6.35-28-generic #49-Ubuntu GA
-MA785GMT-UD2H/GA-MA785GMT-UD2H
May  3 14:38:43 theFourthTower kernel: [1642349.323750] RIP: 0010:[<ffffffff810436c6>]  [<ffffffff810436c6>] native_flush_tlb_others
+0x116/0x120

May  3 14:38:43 theFourthTower kernel: [1642349.323750] RSP: 0018:ffff880224acf7d0  EFLAGS: 00000202
May  3 14:38:43 theFourthTower kernel: [1642349.323750] RAX: 00000000000008f3 RBX: ffff880224acf810 RCX: 0000000000000000
May  3 14:38:43 theFourthTower kernel: [1642349.323750] RDX: 0000000000000003 RSI: 00000000000000f3 RDI: 0000000000000286
May  3 14:38:43 theFourthTower kernel: [1642349.323750] RBP: ffffffff8100aa8e R08: ffff880209b46948 R09: 0000000000000000
May  3 14:38:43 theFourthTower kernel: [1642349.323750] R10: ffff8801eec80d38 R11: 0000000000000000 R12: ffff880100000760
May  3 14:38:43 theFourthTower kernel: [1642349.323750] R13: 0000001f8158b25e R14: ffff880100000e60 R15: ffffffff81109c80
May  3 14:38:43 theFourthTower kernel: [1642349.323750] FS:  00007f61c08f4920(0000) GS:ffff880001f80000(0000) knlGS:00000000f6020710
May  3 14:38:43 theFourthTower kernel: [1642349.323750] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
May  3 14:38:43 theFourthTower kernel: [1642349.323750] CR2: 00007f74e768b8f0 CR3: 00000001c43f8000 CR4: 00000000000006e0
May  3 14:38:43 theFourthTower kernel: [1642349.323750] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
May  3 14:38:43 theFourthTower kernel: [1642349.323750] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
May  3 14:38:43 theFourthTower kernel: [1642349.323750] Process kswapd0 (pid: 76, threadinfo ffff880224ace000, task ffff880224a896e0
)

May  3 14:38:43 theFourthTower kernel: [1642349.323750] Stack:
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  ffff880100000003 00000000f4e7e000 0000000000000000 ffff880209b46680
May  3 14:38:43 theFourthTower kernel: [1642349.323750] <0> ffff880209b46948 00000000f4e7e000 ffff880209b46680 ffff880224acfab8
May  3 14:38:43 theFourthTower kernel: [1642349.323750] <0> ffff880224acf840 ffffffff810437de ffff880224acf830 ffff8801ec971508
May  3 14:38:43 theFourthTower kernel: [1642349.323750] Call Trace:
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff810437de>] ? flush_tlb_page+0x5e/0xa0
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff810422f0>] ? ptep_clear_flush_young+0x50/0x70
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8112959f>] ? page_referenced_one+0x9f/0x110
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff812bbba6>] ? prio_tree_next+0x206/0x240
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff81129e8f>] ? page_referenced_file+0xef/0x130
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8112a417>] ? page_referenced+0x77/0x1f0
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8114e5c0>] ? mem_cgroup_uncharge_cache_page+0x10/0x20
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8110fd8b>] ? shrink_page_list+0x18b/0x580
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8111044d>] ? shrink_inactive_list+0x2cd/0x7f0
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8124b701>] ? fuse_destroy_inode+0x51/0x60
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8116692c>] ? prune_one_dentry+0x5c/0x110
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8110a86a>] ? determine_dirtyable_memory+0x1a/0x30
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8110a917>] ? get_dirty_limits+0x27/0x2f0
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8110e7b2>] ? get_scan_count+0x172/0x2b0
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff81110b1b>] ? shrink_zone+0x1ab/0x230
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff81106d5a>] ? zone_watermark_ok+0x2a/0xf0
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff81111659>] ? balance_pgdat+0x679/0x740
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff81111835>] ? kswapd+0x115/0x300
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8107fab0>] ? autoremove_wake_function+0x0/0x40
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff81111720>] ? kswapd+0x0/0x300
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8107f556>] ? kthread+0x96/0xa0
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8100aee4>] ? kernel_thread_helper+0x4/0x10
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8107f4c0>] ? kthread+0x0/0xa0
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8100aee0>] ? kernel_thread_helper+0x0/0x10
May  3 14:38:43 theFourthTower kernel: [1642349.323750] Code: 01 c0 a8 00 81 c6 f0 00 00 00 4c 89 f7 ff 90 e0 00 00 00 49 83 bd 18 a6 bf 81 00 74 a5 eb 06 90 90 90 90 90 90 f3 90 49 83 3e 00 <75> f8 eb 93 eb 04 90 90 90 90 55 48 89 e5 0f 1f 44 00 00 65 8b 

May  3 14:38:43 theFourthTower kernel: [1642349.323750] Call Trace:
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff810437de>] ? flush_tlb_page+0x5e/0xa0
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff810422f0>] ? ptep_clear_flush_young+0x50/0x70
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8112959f>] ? page_referenced_one+0x9f/0x110
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff812bbba6>] ? prio_tree_next+0x206/0x240
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff81129e8f>] ? page_referenced_file+0xef/0x130
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8112a417>] ? page_referenced+0x77/0x1f0
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8114e5c0>] ? mem_cgroup_uncharge_cache_page+0x10/0x20
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8110fd8b>] ? shrink_page_list+0x18b/0x580
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8111044d>] ? shrink_inactive_list+0x2cd/0x7f0
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8124b701>] ? fuse_destroy_inode+0x51/0x60
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8116692c>] ? prune_one_dentry+0x5c/0x110
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8110a86a>] ? determine_dirtyable_memory+0x1a/0x30
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8110a917>] ? get_dirty_limits+0x27/0x2f0
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8110e7b2>] ? get_scan_count+0x172/0x2b0
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff81110b1b>] ? shrink_zone+0x1ab/0x230
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff81106d5a>] ? zone_watermark_ok+0x2a/0xf0
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff81111659>] ? balance_pgdat+0x679/0x740
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff81111835>] ? kswapd+0x115/0x300
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8107fab0>] ? autoremove_wake_function+0x0/0x40
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff81111720>] ? kswapd+0x0/0x300
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8107f556>] ? kthread+0x96/0xa0
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8100aee4>] ? kernel_thread_helper+0x4/0x10
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8107f4c0>] ? kthread+0x0/0xa0
May  3 14:38:43 theFourthTower kernel: [1642349.323750]  [<ffffffff8100aee0>] ? kernel_thread_helper+0x0/0x10