..it happened today again, after an uptime of less than 48h (iirc)
and quite moderate/small load (building some pkgs, one at a time).
I'm not sure if this provides any additional information, but thought
I'd throw it in for good measure.

It looks almost identical, but today rebooting failed again. :-/

------------8<---------------8<------------
db> bt
ltsleep(1d50600, 204, 11bc680, 0, 60569b8, 1891800) at
netbsd:ltsleep+0x664
uvmfault_anonget(0, 63d0cc0, 60569b0, 11bc400, 1897800, 0) at
netbsd:uvmfault_an
onget+0x13c
uvm_fault(605a838, 44202000, ffffffffffffffff, 63f6da0, 1, 3) at
netbsd:uvm_faul
t+0x420
data_access_fault(63f6f90, 30, 100b0d4, 441fc10c, 11081f, 1814c00) at
netbsd:dat
a_access_fault+0x2d4
?(63f4028, 441fdb80, 78, 63f4000, 100b168, 1d5ae00) at 0x1008e40
rwindow_save(441fdb80, 0, 0, 55b0060, 3e2a000, 2000) at
netbsd:rwindow_save+0xcc

cpu_getmcontext(5e92e00, 55b0090, 55b0050, 1e74750, 63f7440, 1891800) at netbsd:cpu_getmcontext+0x10
sa_upcall_getstate(55b0050, 5e92e00, 372, 11b2568, 55b0010, 5e92d28) at netbsd:sa_upcall_getstate+0x10
sa_upcall0(55b0010, 2, 5e92e00, 0, 0, 0) at netbsd:sa_upcall0+0x98
sa_switch(60822e0, 642a000, 1ca, 11b84c0, 1, 1891800) at netbsd:sa_switch+0x2a4
ltsleep(20da880, 11, 0, 0, 20da890, 0) at netbsd:ltsleep+0x560
biowait(20da880, 20da880, 3, 11b2568, 63f79cc, 1891800) at netbsd:biowait+0x50
uvm_swap_io(0, d60, 1, 100000, 1897990, 1d5ae00) at netbsd:uvm_swap_io+0x1a8
uvm_swap_get(5, 11bf000, 1, 11bc4a8, 46, 0) at netbsd:uvm_swap_get+0x5c
uvmfault_anonget(63f7ca0, 63d0cc0, 60569b0, 11bc400, 1897800, 0) at netbsd:uvmfault_anonget+0x5ac
uvm_fault(605a838, 44202000, ffffffffffffffff, 63f7ce0, 1, 3) at netbsd:uvm_fault+0x420
data_access_fault(63f7ed0, 30, 407642e0, 441fc10c, 800805, 1814c00) at netbsd:data_access_fault+0x2d4
?(251724, badcafe, badcafe, badcafe, badcafe, badcafe) at 0x1008e40
ddb_regs(ffffffffffffffff, ffffffffffffffff, ffffffffffffffff,
ffffffffffffffff,
 ffffffffffffffff, ffffffffffffffff) at 0x407642c8
db> call softclock
0
db> call softclock
0
db> reboot
syncing disks...
simple_lock: lock held
lock: 0x1810af8, currently at: ../../../../kern/kern_synch.c:1159
last locked: ../../../../kern/kern_synch.c:421
last unlocked: ../../../../kern/kern_sa.c:1428
hme0: status=30001<GOTFRAME,RXTOHOST,NORXD>
hme0: status=20001<GOTFRAME,NORXD>

pool_get(PR_WAITOK) with held simple_lock 0x60569b8 CPU 0
../../../../uvm/uvm_f4

pool_get(PR_WAITOK) with held simple_lock 0x60569b8 CPU 0
../../../../uvm/uvm_f4

pool_get(PR_WAITOK) with held simple_lock 0x60569b8 CPU 0
../../../../uvm/uvm_f4

pool_get(PR_WAITOK) with held simple_lock 0x60569b8 CPU 0
../../../../uvm/uvm_f4

pool_get(PR_WAITOK) with held simple_lock 0x60569b8 CPU 0
../../../../uvm/uvm_f4

pool_get(PR_WAITOK) with held simple_lock 0x60569b8 CPU 0
../../../../uvm/uvm_f4

switching with held simple_lock 0x60569b8 CPU 0
../../../../uvm/uvm_fault.c:1034
------------8<---------------8<------------

(there appears to be some terminal problem; sorry for the truncated
lines).

-- 
/ali
:wq