lockmgr: thread <..> unlocking unheld lock

[Andrew Gallatin]

I'm getting tons of these warnings on a new AMD64x2 box when doing
heavy disk activity (buildworld or portsnap):

lockmgr: thread 0xffffff00162a1be0 unlocking unheld lock
KDB: stack backtrace:
lockmgr() at lockmgr+0x6ee
VOP_UNLOCK_APV() at VOP_UNLOCK_APV+0x49
vput() at vput+0x81
lookup() at lookup+0xae2
namei() at namei+0x34d
vn_open_cred() at vn_open_cred+0x208
kern_open() at kern_open+0xfc
open() at open+0x25
syscall() at syscall+0x642
Xfast_syscall() at Xfast_syscall+0xa8
--- syscall (5, FreeBSD ELF64, open), rip = 0x8006e2f4c, rsp = 0x7fffffffe638, rbp = 0x4 ---

This is with -current as of ~9am EDT today.   I've seen 19 in the
course of a j4 buildworld and a portsnap fetch and extract.

Kris reported the same message, but with a different stack here:
http://lists.freebsd.org/pipermail/freebsd-current/2005-September/055142.html


Drew