Chuck Silvers writes:
 > nothing obvious from that info, no.  how about "call dump_kmemstats"?
 > if that doesn't point out anything that you could look at all
 > the various pools to see if you can find the memory that way.
 > unfortunately there's no handy function for that...  yet.
I'll try that if/when I see the problem again...

 > what were you doing at the time (other than compiling something)?
cd /usr/src ; make build
(t0 + 2 days into it)