@User Virtual
Please , be aware about random dmesg stack traces under Xen-4.0.1-rc2
EXT4-fs (sda10): mounted filesystem with ordered data mode
BUG: unable to handle kernel paging request at ffff8801e07bbbe0
IP: [<ffffffff8100e895>] xen_set_pmd+0x24/0x44
PGD 1002067 PUD f374067 PMD f478067 PTE 80100001e07bb065
Oops: 0003 [#1] SMP 
last sysfs file: /sys/devices/virtual/block/dm-2/dm/suspended
CPU 0 
Modules linked in: snd_hda_codec_atihdmi snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_seq_dummy snd_pcm_oss snd_mixer_oss snd_pcm snd_seq_oss snd_seq_midi snd_rawmidi snd_seq_midi_event lp snd_seq snd_timer snd_seq_device parport snd soundcore snd_page_alloc asus_atk0110 ata_generic pata_acpi floppy r8169 mii pata_jmicron
Pid: 3591, comm: udevd Not tainted 2.6.32.15 #16 System Product Name
RIP: e030:[<ffffffff8100e895>]  [<ffffffff8100e895>] xen_set_pmd+0x24/0x44
RSP: e02b:ffff8801e76dfb18  EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8801e07bbbe0 RCX: ffffc00000000f98
RDX: ffffea0000000000 RSI: 0000000000000000 RDI: ffff8801e07bbbe0
RBP: ffff8801e76dfb28 R08: 00007fbb32a0d000 R09: ffff8801e685bd98
R10: 0000000000000000 R11: ffff8801db3271c0 R12: 0000000000000000
R13: ffff880028046970 R14: ffff8801e07bbbe0 R15: ffff8801e52897f8
FS:  00007fbb3087b7a0(0000) GS:ffff880028038000(0000) knlGS:0000000000000000
CS:  e033 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: ffff8801e07bbbe0 CR3: 00000001e2da5000 CR4: 0000000000002660
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process udevd (pid: 3591, threadinfo ffff8801e76de000, task ffff8801da4ca200)
Stack:
 00007fbb2fa00000 00007fbb30ab8000 ffff8801e76dfbe8 ffffffff810e35ef
<0> ffff8801e9b179f0 0000000000000001 ffff8801e76dfb98 00007fbb2f600000
<0> 00007f8000000000 00007fbb00000000 00007fbb30ab7fff 00007fbb30ab7fff
Call Trace:
 [<ffffffff810e35ef>] free_pgd_range+0x213/0x397
 [<ffffffff810e3817>] free_pgtables+0xa4/0xc7
 [<ffffffff810e71fa>] exit_mmap+0xf5/0x12d
 [<ffffffff810528e3>] mmput+0x59/0xcc
 [<ffffffff8110f6d5>] flush_old_exec+0x486/0x565
 [<ffffffff8114a6c8>] load_elf_binary+0x2ed/0x17a1
 [<ffffffff810e4e19>] ? __get_user_pages+0x38b/0x42c
 [<ffffffff81147f63>] ? load_misc_binary+0x6e/0x362
 [<ffffffff811eb32d>] ? ima_iint_find_get+0x29/0x2f
 [<ffffffff811ea35f>] ? T.456+0xbb/0xd2
 [<ffffffff8110ef1a>] search_binary_handler+0xce/0x260
 [<ffffffff8114a3db>] ? load_elf_binary+0x0/0x17a1
 [<ffffffff81110547>] do_execve+0x1cc/0x2b9
 [<ffffffff810114c4>] sys_execve+0x3e/0x55
 [<ffffffff81012f9a>] stub_execve+0x6a/0xc0
Code: 48 83 c4 18 5b c9 c3 55 48 89 e5 41 54 49 89 f4 53 48 89 fb e8 a1 e2 ff ff 48 89 df ff 05 6c 48 9b 00 e8 2b e5 ff ff 84 c0 75 05 <4c> 89 23 eb 16 e8 85 e2 ff ff 4c 89 e6 48 89 df ff 05 51 48 9b 
RIP  [<ffffffff8100e895>] xen_set_pmd+0x24/0x44
 RSP <ffff8801e76dfb18>
CR2: ffff8801e07bbbe0
---[ end trace d5ce5bc928ef5d16 ]---

I would check dmesg output on your own box.?field.comment=@User Virtual
Please , be aware about random dmesg stack traces under Xen-4.0.1-rc2
EXT4-fs (sda10): mounted filesystem with ordered data mode
BUG: unable to handle kernel paging request at ffff8801e07bbbe0
IP: [<ffffffff8100e895>] xen_set_pmd+0x24/0x44
PGD 1002067 PUD f374067 PMD f478067 PTE 80100001e07bb065
Oops: 0003 [#1] SMP 
last sysfs file: /sys/devices/virtual/block/dm-2/dm/suspended
CPU 0 
Modules linked in: snd_hda_codec_atihdmi snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_seq_dummy snd_pcm_oss snd_mixer_oss snd_pcm snd_seq_oss snd_seq_midi snd_rawmidi snd_seq_midi_event lp snd_seq snd_timer snd_seq_device parport snd soundcore snd_page_alloc asus_atk0110 ata_generic pata_acpi floppy r8169 mii pata_jmicron
Pid: 3591, comm: udevd Not tainted 2.6.32.15 #16 System Product Name
RIP: e030:[<ffffffff8100e895>]  [<ffffffff8100e895>] xen_set_pmd+0x24/0x44
RSP: e02b:ffff8801e76dfb18  EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8801e07bbbe0 RCX: ffffc00000000f98
RDX: ffffea0000000000 RSI: 0000000000000000 RDI: ffff8801e07bbbe0
RBP: ffff8801e76dfb28 R08: 00007fbb32a0d000 R09: ffff8801e685bd98
R10: 0000000000000000 R11: ffff8801db3271c0 R12: 0000000000000000
R13: ffff880028046970 R14: ffff8801e07bbbe0 R15: ffff8801e52897f8
FS:  00007fbb3087b7a0(0000) GS:ffff880028038000(0000) knlGS:0000000000000000
CS:  e033 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: ffff8801e07bbbe0 CR3: 00000001e2da5000 CR4: 0000000000002660
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process udevd (pid: 3591, threadinfo ffff8801e76de000, task ffff8801da4ca200)
Stack:
 00007fbb2fa00000 00007fbb30ab8000 ffff8801e76dfbe8 ffffffff810e35ef
<0> ffff8801e9b179f0 0000000000000001 ffff8801e76dfb98 00007fbb2f600000
<0> 00007f8000000000 00007fbb00000000 00007fbb30ab7fff 00007fbb30ab7fff
Call Trace:
 [<ffffffff810e35ef>] free_pgd_range+0x213/0x397
 [<ffffffff810e3817>] free_pgtables+0xa4/0xc7
 [<ffffffff810e71fa>] exit_mmap+0xf5/0x12d
 [<ffffffff810528e3>] mmput+0x59/0xcc
 [<ffffffff8110f6d5>] flush_old_exec+0x486/0x565
 [<ffffffff8114a6c8>] load_elf_binary+0x2ed/0x17a1
 [<ffffffff810e4e19>] ? __get_user_pages+0x38b/0x42c
 [<ffffffff81147f63>] ? load_misc_binary+0x6e/0x362
 [<ffffffff811eb32d>] ? ima_iint_find_get+0x29/0x2f
 [<ffffffff811ea35f>] ? T.456+0xbb/0xd2
 [<ffffffff8110ef1a>] search_binary_handler+0xce/0x260
 [<ffffffff8114a3db>] ? load_elf_binary+0x0/0x17a1
 [<ffffffff81110547>] do_execve+0x1cc/0x2b9
 [<ffffffff810114c4>] sys_execve+0x3e/0x55
 [<ffffffff81012f9a>] stub_execve+0x6a/0xc0
Code: 48 83 c4 18 5b c9 c3 55 48 89 e5 41 54 49 89 f4 53 48 89 fb e8 a1 e2 ff ff 48 89 df ff 05 6c 48 9b 00 e8 2b e5 ff ff 84 c0 75 05 <4c> 89 23 eb 16 e8 85 e2 ff ff 4c 89 e6 48 89 df ff 05 51 48 9b 
RIP  [<ffffffff8100e895>] xen_set_pmd+0x24/0x44
 RSP <ffff8801e76dfb18>
CR2: ffff8801e07bbbe0
---[ end trace d5ce5bc928ef5d16 ]---

I would check dmesg output on your own box.