[521218.791380] BUG: unable to handle kernel NULL pointer dereference at 000000ad
[521218.791391] IP: [<f819b0d7>] ttm_tt_swapout+0x57/0x240 [ttm]
[521218.791410] *pde = 00000000 
[521218.791414] Oops: 0000 [#1] SMP 
[521218.791418] last sysfs file: /sys/devices/pci0000:00/0000:00:08.0/host3/target3:0:0/3:0:0:0/block/sdb/uevent
[521218.791424] Modules linked in: btrfs zlib_deflate crc32c libcrc32c ufs qnx4 hfsplus hfs minix ntfs msdos jfs xfs exportfs reiserfs nls_iso8859_1 nls_cp437 vfat fat usb_storage binfmt_misc snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep nouveau snd_pcm snd_seq_midi snd_rawmidi snd_seq_midi_event ttm drm_kms_helper snd_seq drm snd_timer snd_seq_device snd agpgart soundcore ppdev lp parport_pc i2c_algo_bit psmouse snd_page_alloc i2c_nforce2 serio_raw k8temp parport sata_nv pata_amd forcedeth floppy
[521218.791467] 
[521218.791472] Pid: 759, comm: ttm_swap Not tainted 2.6.35-22-generic #33-Ubuntu NF61S-M2A/NF61S-M2A
[521218.791477] EIP: 0060:[<f819b0d7>] EFLAGS: 00010286 CPU: 0
[521218.791484] EIP is at ttm_tt_swapout+0x57/0x240 [ttm]
[521218.791488] EAX: 00000001 EBX: 00000000 ECX: f5c802c0 EDX: cf625b00
[521218.791491] ESI: f1fd5600 EDI: f1fd5628 EBP: f56bfebc ESP: f56bfe94
[521218.791495]  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
[521218.791499] Process ttm_swap (pid: 759, ti=f56be000 task=f5a47230 task.ti=f56be000)
[521218.791502] Stack:
[521218.791504]  00000000 cf625b00 cf625b00 02037000 f5c802c0 00000001 f4c8007c 00000000
[521218.791512] <0> f1fd5600 f1fd5628 f56bff14 f819d402 00000000 00000000 00000000 f5a8ab4c
[521218.791519] <0> f5a8ab58 f1fd5638 00000000 02037000 00002037 00000000 00000000 00010001
[521218.791528] Call Trace:
[521218.791538]  [<f819d402>] ? ttm_bo_swapout+0x1d2/0x250 [ttm]
[521218.791547]  [<c0355154>] ? rb_insert_color+0x84/0x110
[521218.791555]  [<f819a430>] ? ttm_shrink+0xa0/0x130 [ttm]
[521218.791561]  [<c013eabd>] ? finish_task_switch+0x3d/0xc0
[521218.791569]  [<f819a4e7>] ? ttm_shrink_work+0x27/0x30 [ttm]
[521218.791576]  [<c0161a4e>] ? run_workqueue+0x8e/0x150
[521218.791584]  [<f819a4c0>] ? ttm_shrink_work+0x0/0x30 [ttm]
[521218.791590]  [<c0161b94>] ? worker_thread+0x84/0xe0
[521218.791595]  [<c0165e10>] ? autoremove_wake_function+0x0/0x50
[521218.791601]  [<c0161b10>] ? worker_thread+0x0/0xe0
[521218.791605]  [<c01659e4>] ? kthread+0x74/0x80
[521218.791609]  [<c0165970>] ? kthread+0x0/0x80
[521218.791615]  [<c010363e>] ? kernel_thread_helper+0x6/0x10
[521218.791617] Code: fa 01 00 00 8b 45 e8 f6 40 10 02 0f 85 83 01 00 00 8b 4d e0 85 c9 89 4d dc 0f 84 94 01 00 00 8b 55 dc 8b 4d e8 8b 42 0c 8b 40 10 <8b> 80 ac 00 00 00 89 45 e4 8b 49 14 85 c9 0f 84 15 01 00 00 31 
[521218.791656] EIP: [<f819b0d7>] ttm_tt_swapout+0x57/0x240 [ttm] SS:ESP 0068:f56bfe94
[521218.791665] CR2: 00000000000000ad
[521218.791669] ---[ end trace 8f330bbb4e96bf4d ]---