Problem: Xen 3.3.1 with FreeBSD 8.0 RC1

[Carsten Heesch]

I realised that it's still possible to use 8.0-BETA* as a target for  
freebsd-update. So I investigated a bit further. For whatever it's  
worth:

The problems described earlier started with BETA-4.

BETA-3 is fine with both GENERIC and XENHVM kernel, except that I see  
this on the console and in dmesg every now and then (with both kernels):


lock order reversal:
  1st 0xffffff8014810620 bufwait (bufwait) @ /usr/src/sys/kern/ 
vfs_bio.c:2559
  2nd 0xffffff00015a7c00 dirhash (dirhash) @ /usr/src/sys/ufs/ufs/ 
ufs_dirhash.c:285
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x2a
_witness_debugger() at _witness_debugger+0x2e
witness_checkorder() at witness_checkorder+0x81e
_sx_xlock() at _sx_xlock+0x55
ufsdirhash_acquire() at ufsdirhash_acquire+0x33
ufsdirhash_add() at ufsdirhash_add+0x19
ufs_direnter() at ufs_direnter+0x88b
ufs_makeinode() at ufs_makeinode+0x31c
VOP_CREATE_APV() at VOP_CREATE_APV+0x8d
vn_open_cred() at vn_open_cred+0x423
kern_openat() at kern_openat+0x179
syscall() at syscall+0x1af
Xfast_syscall() at Xfast_syscall+0xe1
--- syscall (5, FreeBSD ELF64, open), rip = 0x800e32dfc, rsp =  
0x7fffffffe608, rbp = 0x1a4 ---


I though this might be XENHVM kernel related, but it happens with  
GENERIC kernel as well. Not sure if this is related to XEN at all.



Cheers
Carsten