duplicate lock of same type: "vnode interlock"

Hi!

Today at:
# uname -a
FreeBSD test.ipt.ru 7.0-CURRENT FreeBSD 7.0-CURRENT #3: Fri Sep 21 18:36:28 MSD 2007     bsam_at_test.ipt.ru:/usr/obj/usr/src/sys/TEST  amd64

I've got:
-----
Mounting local file systems:acquiring duplicate lock of same type: "vnode interlock"
 1st vnode interlock _at_ /usr/src/sys/kern/vfs_vnops.c:807
 2nd vnode interlock _at_ /usr/src/sys/kern/vfs_subr.c:2081
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x2a
witness_checkorder() at witness_checkorder+0x5f8
_mtx_lock_flags() at _mtx_lock_flags+0x75
vrefcnt() at vrefcnt+0x31
null_checkvp() at null_checkvp+0x1d
null_lock() at null_lock+0x5b
VOP_LOCK1_APV() at VOP_LOCK1_APV+0x79
_vn_lock() at _vn_lock+0x94
nullfs_root() at nullfs_root+0x59
vfs_donmount() at vfs_donmount+0x1150
nmount() at nmount+0x97
syscall() at syscall+0x1f6
Xfast_syscall() at Xfast_syscall+0xab
--- syscall (378, FreeBSD ELF64, nmount), rip = 0x80068465c, rsp = 0x7fffffffe518, rbp = 0x7fffffffe520 ---
-----

Should I worry about it?
The system boots and seems to we fine...


WBR
-- 
Boris Samorodov (bsam)
Research Engineer, http://www.ipt.ru Telephone & Internet SP
FreeBSD committer, http://www.FreeBSD.org The Power To Serve