Ubuntu kernel has updates to 12:
Booting 'Ubuntu 11.04, kernel 2.6.38-12-virtual'

And here's the same bug again:
cloud-init boot finished at Mon, 07 Nov 2011 10:06:53 +0000. Up 31.47 seconds
[82511.071442] ------------[ cut here ]------------
[82511.071467] kernel BUG at /build/buildd/linux-2.6.38/mm/swapfile.c:2552!
[82511.071477] invalid opcode: 0000 [#1] SMP 
[82511.071490] last sysfs file: /sys/devices/system/cpu/cpu1/cache/index2/shared_cpu_map
[82511.071501] Modules linked in: nfsd exportfs nfs lockd fscache nfs_acl auth_rpcgss sunrpc acpiphp
[82511.071540] 
[82511.071548] Pid: 15603, comm: apache2 Not tainted 2.6.38-12-virtual #51-Ubuntu  
[82511.071583] EIP: 0061:[<c0218bb6>] EFLAGS: 00210246 CPU: 1
[82511.071597] EIP is at swap_count_continued.clone.15+0x1a6/0x1b0
[82511.071614] EAX: f57a68f5 EBX: 000008f5 ECX: 80000000 EDX: 00000000
[82511.071624] ESI: ed1c9820 EDI: 00000080 EBP: e6e55de8 ESP: e6e55dd8
[82511.071634]  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0069
[82511.071649] Process apache2 (pid: 15603, ti=e6e54000 task=e4c225e0 task.ti=e6e54000)
[82511.071659] Stack:
[82511.071665]  ed3d9e80 eac760c0 00000000 000058f5 e6e55e10 c0218d0d 00000080 c0636fed
[82511.071693]  e6e55e10 000058f5 edc65000 000058f5 e6e55eec eac760c0 e6e55e24 c021ae31
[82511.071722]  e54f1de0 e6e55eec 00000000 e6e55e80 c0209d53 5eab6025 80000000 ecc7a100
[82511.071751] Call Trace:
[82511.071761]  [<c0218d0d>] swap_entry_free+0x14d/0x170
[82511.071774]  [<c0636fed>] ? _raw_spin_lock+0xd/0x10
[82511.071785]  [<c021ae31>] free_swap_and_cache+0x51/0x100
[82511.071796]  [<c0209d53>] zap_pte_range+0x2d3/0x410
[82511.071809]  [<c0105755>] ? pte_pfn_to_mfn+0x85/0xa0
[82511.071821]  [<c0209fa5>] unmap_page_range+0x115/0x1b0
[82511.071831]  [<c020a607>] unmap_vmas+0x137/0x280
[82511.071842]  [<c02109de>] exit_mmap+0x9e/0x160
[82511.071855]  [<c0156c1b>] mmput+0x3b/0xd0
[82511.071865]  [<c015cd0e>] exit_mm+0xfe/0x130
[82511.071875]  [<c0637138>] ? _raw_spin_lock_irq+0x18/0x20
[82511.071886]  [<c015ce59>] do_exit+0x119/0x350
[82511.071896]  [<c020f8ae>] ? do_munmap+0x1fe/0x280
[82511.071907]  [<c015d1ee>] do_group_exit+0x3e/0xa0
[82511.071917]  [<c015d268>] sys_exit_group+0x18/0x20
[82511.071928]  [<c010ab5f>] sysenter_do_call+0x12/0x28
[82511.071937] Code: ff 89 f0 e8 dd 40 f2 ff 01 d8 8d 76 00 c6 00 00 ba 01 00 00 00 eb 9b 89 f8 3c 80 0f 94 c0 e9 90 fe ff ff 0f 0b 0f 0b 0f 0b 0f 0b <0f> 0b 90 8d b4 26 00 00 00 00 55 89 e5 57 56 53 83 ec 14 3e 8d 
[82511.072010] EIP: [<c0218bb6>] swap_count_continued.clone.15+0x1a6/0x1b0 SS:ESP 0069:e6e55dd8
[82511.072010] ---[ end trace 8c1ca21999464a70 ]---
[82511.072010] Fixing recursive fault but reboot is needed!
[82511.072010] BUG: scheduling while atomic: apache2/15603/0x00000002
[82511.072010] Modules linked in: nfsd exportfs nfs lockd fscache nfs_acl auth_rpcgss sunrpc acpiphp
[82511.072010] Pid: 15603, comm: apache2 Tainted: G      D     2.6.38-12-virtual #51-Ubuntu
[82511.072010] Call Trace:
[82511.072010]  [<c0147dd2>] ? __schedule_bug+0x62/0x70
[82511.072010]  [<c06351e3>] ? schedule+0x713/0x740
[82511.072010]  [<c015975b>] ? vprintk+0x18b/0x480
[82511.072010]  [<c015d05b>] ? do_exit+0x31b/0x350
[82511.072010]  [<c06349a9>] ? printk+0x30/0x37
[82511.072010]  [<c0638656>] ? oops_end+0x96/0xd0
[82511.072010]  [<c010df24>] ? die+0x54/0x80
[82511.072010]  [<c0637d66>] ? do_trap+0x96/0xd0
[82511.072010]  [<c010b6f0>] ? do_invalid_op+0x0/0xa0
[82511.072010]  [<c010b77b>] ? do_invalid_op+0x8b/0xa0
[82511.072010]  [<c0218bb6>] ? swap_count_continued.clone.15+0x1a6/0x1b0
[82511.072010]  [<c010775b>] ? do_stolen_accounting+0x21b/0x250
[82511.072010]  [<c01073aa>] ? xen_force_evtchn_callback+0x1a/0x30
[82511.072010]  [<c01f1aee>] ? get_page_from_freelist+0x12e/0x320
[82511.072010]  [<c0105755>] ? pte_pfn_to_mfn+0x85/0xa0
[82511.072010]  [<c0637aff>] ? error_code+0x67/0x6c
[82511.072010]  [<c0218bb6>] ? swap_count_continued.clone.15+0x1a6/0x1b0
[82511.072010]  [<c0218d0d>] ? swap_entry_free+0x14d/0x170
[82511.072010]  [<c0636fed>] ? _raw_spin_lock+0xd/0x10
[82511.072010]  [<c021ae31>] ? free_swap_and_cache+0x51/0x100
[82511.072010]  [<c0209d53>] ? zap_pte_range+0x2d3/0x410
[82511.072010]  [<c0105755>] ? pte_pfn_to_mfn+0x85/0xa0
[82511.072010]  [<c0209fa5>] ? unmap_page_range+0x115/0x1b0
[82511.072010]  [<c020a607>] ? unmap_vmas+0x137/0x280
[82511.072010]  [<c02109de>] ? exit_mmap+0x9e/0x160
[82511.072010]  [<c0156c1b>] ? mmput+0x3b/0xd0
[82511.072010]  [<c015cd0e>] ? exit_mm+0xfe/0x130
[82511.072010]  [<c0637138>] ? _raw_spin_lock_irq+0x18/0x20
[82511.072010]  [<c015ce59>] ? do_exit+0x119/0x350
[82511.072010]  [<c020f8ae>] ? do_munmap+0x1fe/0x280
[82511.072010]  [<c015d1ee>] ? do_group_exit+0x3e/0xa0
[82511.072010]  [<c015d268>] ? sys_exit_group+0x18/0x20
[82511.072010]  [<c010ab5f>] ? sysenter_do_call+0x12/0x28

So now our high traffic website crashed, ssh to instances did not work, so I had to terminate all and autostart new but they will soon crash again like this.  At instance start it gets new kernel from repos. How do I prevent this? Get new kernel with patch? Or get the old one stay? 

What is the status of the fix getting to main kernel? And Oneiric version too?

Help?