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From: jxf@altair.cis.ksu.edu (Jerry Frain)
Newsgroups: comp.sys.mac.system
Subject: Preemptive Scheduling (was Re: True Multitasking)
Message-ID: <1991Jan16.035715.4711@maverick.ksu.ksu.edu>
Date: 16 Jan 91 03:57:15 GMT
References: <19019@shlump.nac.dec.com> <48122@apple.Apple.COM>
Sender: news@maverick.ksu.ksu.edu (The News Guru)
Organization: Kansas State University
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[ Note: subject was changed because this thread is inappropriately named ]

heksterb@Apple.COM (Ben Hekster) writes:

>  Have you ever
>experienced mouse operations in preemptive multitasking environments?  My
>experience with X Window on high-performance workstations (various window
>managers), for instance has been that feedback is frequently so *awful*
>(intermittent, or no reaction to mouse movements at all for periods on the
>order of many seconds) as to make complicated interactions extremely
>difficult.  (No flame on X intended, just an observation on the workstation
>environment)

I always find this argument quite humorous, since I do all of my work
at work on a Sun workstation using X, while I do all of my work at home
on a Mac SE/30.

I really have no problems with mouse/pointer movement on the Sun
workstation I use at work.  If there are fewer than ninety existing
processes, and four or more actually wanting to do something at that
time, then I may start to feel it.  I just renice my X server, and
everything is fine until the load climbs up quite a bit more.

Shove a floppy in your disk drive on your Mac and move your mouse around
and tell me how your Mac is *so* responsive (IIfx owners may be exceptions
to this test).

My point is, a preemptive scheduler on a single-user system is really
not a problem -- at least no more than cooperative, especially when an
intelligent scheme is used to assign priorities properly.

Regards,

  --Jerry

--
Jerry Frain -- Systems Programmer               Kansas State University
                                        Department of Computing & Info Sciences
Internet : jxf@cis.ksu.edu                         Manhattan, Kansas
UUCP     : ...!rutgers!ksuvax1!jxf