panic from HEAD of 3/9: 0xc4aab330: Non-zero write count

Got this on a 4 CPU PII Xeon 450 running HEAD with 4BSD and PREEMPTION (I
think) doing a loop of buildworld -j 12:

FreeBSD/i386 (deimos.baldwin.cx) (ttyd0)

login: panic: 0xc4aab330: Non-zero write count
cpuid = 1
KDB: enter: panic
[thread pid 48553 tid 100264 ]
Stopped at      kdb_enter+0x30: leave
db>
db> tr
Tracing pid 48553 tid 100264 td 0xc2a8a5c0
kdb_enter(c0720b94,1,c0727f31,e03bb91c,c2a8a5c0) at kdb_enter+0x30
panic(c0727f31,c4aab330,c0727e5b,326,c3b20e38) at panic+0x14e
getnewvnode(c07260fa,c20d1000,c0766fa0,e03bb9bc,80) at getnewvnode+0x269
ffs_vget(c20d1000,1c8e3d,2,e03bba30,e03bba34) at ffs_vget+0xb9
ufs_lookup(e03bbb00,e03bbb98,e03bbc9c,e03bbb98,e03bbb3c) at ufs_lookup+0xa41
VOP_CACHEDLOOKUP_APV(c0766fa0,e03bbb00,e03bbc9c,e03bbb38,c2a8a5c0) at VOP_CACHEDLOOKUP_APV+0xbc
vfs_cache_lookup(e03bbb98,c3cfd330,e03bbc9c,c3cfd330,e03bbbb4) at vfs_cache_lookup+0xde
VOP_LOOKUP_APV(c0766fa0,e03bbb98,c2a8a5c0,731,0) at VOP_LOOKUP_APV+0xbc
lookup(e03bbc74,0,c0727849,a9,c3cfd384) at lookup+0x3d0
namei(e03bbc74,ffffffdf,2,c2a8a5c0,c20d1000) at namei+0x428
kern_unlink(c2a8a5c0,804f4c8,0,e03bbd40,c06ddcb0) at kern_unlink+0x40
unlink(c2a8a5c0,e03bbd14,4,3ff,1) at unlink+0x22
syscall(2f,804002f,bfbf002f,0,804d000) at syscall+0x2a0
Xint0x80_syscall() at Xint0x80_syscall+0x1f
--- syscall (10, FreeBSD ELF32, unlink), eip = 0x280be03f, esp = 0xbfbfe65c, ebp = 0xbfbfe688 ---
db> x 0xc4aab330,40
0xc4aab330:     8               c0710a12        c074fbc0        0
0xc4aab340:     0               c2986220        c2b66894        0
0xc4aab350:     0               0               c4aab354        d625a
0xc4aab360:     c4aab330        0               0               0
0xc4aab370:     0               0               0               0
0xc4aab380:     0               c077cf7c        1004040         0
0xc4aab390:     0               500000          c07260fa        33
0xc4aab3a0:     ffffffff        0               c07564e8        c0727fab
0xc4aab3b0:     c0727fab        30000           0               0
0xc4aab3c0:     0               4               0               c4aab384
0xc4aab3d0:     0               0               0               80
0xc4aab3e0:     0               ffffffff        0               c2a46b58
0xc4aab3f0:     c4aab3a8        0               c4aab3f4        0
0xc4aab400:     0               0               c4aab404        0
0xc4aab410:     0               0               0               c075c4a8
0xc4aab420:     2000            0               c21e7b60        c2b2ddb8
db>

-- 
John Baldwin <jhb_at_FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve"  =  http://www.FreeBSD.org