I just fired up a release I built from yesterdays sources. Some weird  
stuff is going on. I just typed tail /kern/msgbuf and the system   
froze. This is a Dual 1.4 GHz P III. I can't ssh in, can't login to  
any virtual terminal, but I can switch virtual terminals and I can  
still ping the box. Typing on the keyboard makes the cursor flicker,  
but nothing actually shows up, nor does the cursor move.

If I break into DB, I can see the process, but I can't kill it.

Stopped in pid 877.1 (tail) at netbsd:cpu_Debugger+0x4: leave
db{1}> bt
cpu_Debugger+0x4
internal_command+0xc
wskbd_translate+0x6c
wskbd_input+0x4b
pckbd_input+0x53
pckbportintr+0x3a
pckbcintr+0x94
intr_biglock_wrapper+0x18
Xintr_ioapic_edge1+0x9c
--- interrupt ---
vn_lock +0x24
vn_close+0x21
vn_closefile+0x1a
closef+0xf9
fdfree+0xa9
exit1+0x1e2
postsig+0x272
trap() at netbsd:trap+0x3b0
--- trap (number 6) ---
0x8049439:
db{1}> mach cpu
addr    dev    id    flags    ipis    curproc    fpcurproc
0xc07e73c0    cpu0    1    3009    0    0xcf32bd68    0xcf32ba50
0xc4f40800    cpu1    0    f002    0    0xcf32b7bc    0x0
db{1}> mach cpu 0
using CPU 0
db{1}> bt
_kernel_lock_acquire_count+0x90
mi_switch+0x13a
ltsleep+0x425
uvm_aiodone_daemon+0x167
db{1}>

Deadlock?