panic at vm_page_wire with FreeBSD 9.0 Beta 3

Hi,

I'm facing a kernel panic at vm_page_wire(). Page is locked with
vm_page_lock() yet i get the following panic
panic: mutex page lock not owned at /usr/src/sys/vm/vm_page:1845

Code sequence is as below
vm_page_lock(pp);
vm_page_lock_assert(pp, MA_OWNED); /* No panic here */
vm_page_wire(pp); /* Panic here for the same assertion as above, strange */
vm_page_unlock(pp);

Kernel on the system is unchanged after install. The only thing which
occurred out the way was that the first time install failed for checksum
mismatch for src.txz. Also there were some SCSI errors/warnings with the CD
drive during install. So the next time, i only installed the base and
kernel and later unpacked src.txz under /usr/src . Could this lead to any
issues ?

Attached is a test module (vmtest) and the makefile used. Uname output from
the system is

FreeBSD scache 9.0-BETA3 FreeBSD 9.0-BETA3 #0: Sat Sep 24 21:31:28 UTC
2011
root_at_farrell.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC  amd64

Is there anything i'm doing wrong here ? Kindly help.

Regards,
Penta