All,

Thanks to fvdl's patient mentoring, we've isolated the code fragment that would
cause the amd64 to hang when physical memory became exhausted.  My machine has
been problem-free for the last 48 hours, so things look good ...

I've just committed the workaround to -current (sys/arch/amd64/amd64/pmap.c
revision 1.10) and requested a pullup to 2.0.

-- Chris
	GPG key FEB9DE7F (91AF 4534 4529 4BCC 31A5  938E 023E EEFB FEB9 DE7F)