> Date: Tue, 10 Sep 1996 00:14:29 +0930 (CST)
> From: Mark Newton <newton@cleese.apana.org.au>
> 
> I've been doing some looking in to the "everything dumps core" bug on
> Sun-3 NetBSD and have a (possibly, but not necessarily) related issue
> to raise.

My strongest suspicion at present is that we have unwanted reentrance
into some VM or pmap code.  I'm trying to put in some checks for that.

> Is there any compelling reason why the vmapbuf() routine XXX'ed with
> the text, "This implementation is a total crock," shouldn't be replaced
> with the (apparently rewritten drop-in replacement) version from the
> Amiga, Atari or Mac68k ports?  I'm not suggesting this this'll stop
> "everything dumps core," but it's probably worthwhile as a general 
> code improvement...
> 
> [ it works with my kernel, btw, in case anyone was wondering ]
> 
>      - mark

The implementations are essentially identical.  The comment saying
"This implementation is a total crock" is referring to the fact
that this mapping is not known to the VM system, and should be.
Fixing that would require changes outside vmapbuf()/vunmapbuf().