Fedora xen - Dec 2007 - Panic with 32bit RHEL4 on 64bit RHEL5

Am experiencing a domU panic when running 32bit RHEL4 (2.6.9-67.ELxenU) on 64bit
RHEL5 (2.6.18-53.el5xen) under high load conditions. Problem has not occurred
(so far) when hosting the same domU on 32bit RHEL5, so I''m a little
stumped. Any ideas or recommendations would be greatly appreciated. Thanks in
advance!

Unable to handle kernel NULL pointer dereference at virtual address 00000000 
printing eip: 
c01496c9 
2c84c000 -> *pde = 00000000:9a3e9027 
1b3eb000 -> *pme = 00000000:bfd81067 
1c064000 -> *pte = 00000000:00000000 
Oops: 0000 [#1] 
SMP 
Modules linked in: md5 ipv6 autofs4 sunrpc dm_mirror xennet ext3 jbd dm_mod
xenblk sd_mod scsi_mod
CPU: 0 
EIP: 0061:[<c01496c9>] Not tainted VLI 
EFLAGS: 00010287 (2.6.9-67.ELxenU) 
EIP is at zap_pte_range+0x279/0x489 
eax: 00046000 ebx: 00000000 ecx: f5392000 edx: 00000000 
esi: 000b0b21 edi: c1f75bc0 ebp: 00000000 esp: e5aa3e04 
ds: 007b es: 007b ss: 0068 
Process amavisd (pid: 30894, threadinfo=e5aa3000 task=e54146c0) 
Stack: b0b21067 00000000 00000000 00000000 00000000 00000000 00046000 0a800000 
c202d2a0 e548a2a8 0a846000 00000000 0a800000 c0149980 c202d2a0 e548a2a0 
0a800000 00046000 00000000 0a7c6000 e5486008 0a846000 00000000 c01499e5 
Call Trace: 
[<c0149980>] zap_pmd_range+0xa7/0xcb 
[<c01499e5>] unmap_page_range+0x41/0x65 
[<c0149ad6>] unmap_vmas+0xcd/0x1e8 
[<c014ec19>] exit_mmap+0x85/0x15b 
[<c011a2d9>] mmput+0x52/0x77 
[<c011a74b>] copy_mm+0x36c/0x396 
[<c011b26a>] copy_process+0x6b5/0xb0b 
[<c011b7ad>] do_fork+0x8a/0x16b 
[<c0105cff>] sys_clone+0x24/0x28 
[<c010734f>] syscall_call+0x7/0xb 
Code: 8b 4c 24 14 8b 41 04 85 c0 75 0a 83 39 00 0f 45 c1 89 44 24 14 c7 44 24 10
00 00 00 00 8b 44 24 18 39 44 24 10 0f 83 08 02 00 00 <8b> 55 00 8b 4d 04
85 d2 75 08 85 c9 0f 84 e6 01 00 00 88 d0 a8

Jim Klein wrote:
> Am experiencing a domU panic when running 32bit RHEL4 (2.6.9-67.ELxenU)
> on 64bit RHEL5 (2.6.18-53.el5xen) under high load conditions. Problem
> has not occurred (so far) when hosting the same domU on 32bit RHEL5, so
> I''m a little stumped. Any ideas or recommendations would be
greatly
> appreciated. Thanks in advance!
32 PV on 64 hypervisor is known to be unstable with RHEL-5.1 as the dom0.  This
should be addressed in an upcoming release.

Chris Lalancette