Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!cs.utexas.edu!uunet!portal!cup.portal.com!ts
From: ts@cup.portal.com (Tim W Smith)
Newsgroups: comp.sys.mac
Subject: Re: Apple System 7.0
Message-ID: <18888@cup.portal.com>
Date: 28 May 89 09:07:08 GMT
References: <17183@usc.edu> <4679@okstate.UUCP> <1925@internal.Apple.COM> <61086@yale-celray.yale.UUCP> <9344@polya.Stanford.EDU> <2097@ccnysci.UUCP>
Organization: The Portal System (TM)
Lines: 24

If you've got kernel sources for Unix, try hacking it to not
use pre-emptive multitasking.  It might be interesting to see
what happens.

The first compute bound process will, of course, hang the system,
but I bet a lot of things would work well.  Most processes are
going to give up the CPU quite a lot because they will be doing
IO, which will lead to a task switch every time they have to
sleep waiting for disk IO.

I've always wanted to do this, but I never remembered when I had
kernel sources.

There's a story that used to be told at the computer center at
Caltech that the clock once broke on the PDP-10 ( that tells how
old this story is ) that was used for most timesharing at 'Tech,
and that no one figured out what was wrong for over a week.  The
system seemed a bit more sluggish than usual, but otherwise
worked ok.

One that other hand, this is not really relevant here, since
MultiFinder does not task switch when IO is in progress.

					Tim Smith