On Thu, 21 Sep 1995, Theo de Raadt wrote:

> by the way, in that recent discussion about pmap problems
> (ie. clearing mem, *NULL in kernel, etc) was any concensus reached? i
> have been fighting the same bug/bugs for a while myself, and have had
> to impliment similar workarounds.

As far as I can tell, a combination of Michael Hitch's pmap patch and
clearing out all fast RAM results in a stable system.  Clearing out fast
RAM is an ugly kluge and someone should look into the real cause, but if 
you're just concerned with running a kernel that doesn't crash, then it's 
a reasonable compromise.

Eduardo