After some memory intensive tasks (Xserver, ramdisk (mount_mfs), a lot of
compileng (for some time two big makes in parallel), etc) the kernel startet
throwing out these messages:

Sep 14 00:18:51 RiscPC /netbsd: pmap: Cannot allocate L1 page table, sleeping ..
.
Sep 14 00:18:51 RiscPC /netbsd: pmap: Cannot allocate physical memory for L1 (12
)
Sep 14 00:18:51 RiscPC /netbsd: pmap: Cannot allocate L1 page table, sleeping ..
.
Sep 14 00:18:51 RiscPC /netbsd: pmap: Cannot allocate physical memory for L1 (12
)
Sep 14 00:19:01 RiscPC /netbsd: pmap: Cannot allocate L1 page table, sleeping ..
.
Sep 14 00:19:01 RiscPC /netbsd: pmap: Cannot allocate physical memory for L1 (12
)
Sep 14 00:19:01 RiscPC /netbsd: pmap: Cannot allocate L1 page table, sleeping ..
.
Sep 14 00:19:01 RiscPC /netbsd: pmap: Cannot allocate physical memory for L1 (12
)
[...]

I wasn't able to recover from this. ps, top, skill made all consoles
and remote terminals freeze and after a while I wasn't able to log into this
machine anymore. The start of the kernel debugger caused an immediatly
reboot...

This may be a similar problem, as Jason describes in PR#5666 over a
year ago, but I'm not sure since he writes about L2 PTs.
http://www.NetBSD.org/cgi-bin/query-pr-single.pl?number=5666
-- 
Dies ist Thilos Unix Signature! Viel Spass damit.