Path: utzoo!attcan!uunet!super!rminnich
From: rminnich@super.ORG (Ronald G Minnich)
Newsgroups: comp.sys.amiga
Subject: Re: OS/2 vs. Pournelle
Message-ID: <800@super.ORG>
Date: 30 Sep 88 13:37:59 GMT
References: <5384@fluke.COM> <9362@swan.ulowell.edu>
Sender: uucp@super.ORG
Reply-To: rminnich@metropolis.UUCP (Ronald G Minnich)
Organization: Supercomputing Research Center, Lanham, MD
Lines: 17

in article <5384@fluke.COM> kurt@tc.fluke.COM (Kurt Guntheroth) writes:
>Here's a question I want answered...Do PS/2 (OS/2) machines have memory
>protection?  I don't mean software segments.  I mean hardware protection.
AN even more interesting question. (Yes, OS/2 has protection btw. But
that is only one of the bomb-producing issues. Unix V6 had protection 
and it crashed *often*- that's where i cut my kernel teeth). 
  But how does the message passing work? Is it 'copy the message' or 
'map it into your space'? If it is the latter, where do they get mapped
in? To the same virtual address per process? Or to a different virtual 
address? If to a different virtual address, then all the pointers
in the message are invalid. If to the same, how do they guarantee
that there is not something already there? 
   On the amiga if it ever does got memory management it is done 
via the equivalent of 'map it in'. Since all processes live in a large
linear address space it will work right even with memory management- it 
will still be VERY efficient. Is OS/2 copy or map in? Anybody know?
ron