Subject: Re: vmapbuf() in vm_machdep.c is dodgy...
To: Mark Newton <newton@cleese.apana.org.au>
From: Jason Thorpe <thorpej@nas.nasa.gov>
List: port-sun3
Date: 09/09/1996 09:07:08
On Tue, 10 Sep 1996 00:14:29 +0930 (CST) 
 Mark Newton <newton@cleese.apana.org.au> wrote:

 > 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...

Heh ... take a look at the mvme68k and hp300 vmapbuf() functions.  
They're the same as the amiga, but with the orginal comment (i..e. the 
"total crock" one :-)

The sun3 version is essentially the same, with two exceptions... the sun3 
version uses kernel_map instead of phys_map (it _probably_ should use 
phys_map), and it flushes the VAC on systems that require it (the hp300 
doesn't have this requirement, since the hp300 pmap cache-inhibits pages 
which are multiply mapped on the hp320/hp350).

So, really, dropping in the amiga version verbatim would break the 
sun3/260 :-)

 > [ it works with my kernel, btw, in case anyone was wondering ]

Which model do you have?  It's probably not one with a cache?

 -- save the ancient forests - http://www.bayarea.net/~thorpej/forest/ -- 
Jason R. Thorpe                                       thorpej@nas.nasa.gov
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