Path: utzoo!attcan!uunet!cs.utexas.edu!sun-barr!ames!apple!oliveb!amiga!boing!dale
From: dale@boing.UUCP (Dale Luck)
Newsgroups: comp.sys.amiga
Subject: Re: Apple System 7.0
Message-ID: <761@boing.UUCP>
Date: 17 May 89 16:11:09 GMT
References: <17148@usc.edu> <24279@agate.BERKELEY.EDU> <18268@cup.portal.com> <17183@usc.edu> <21814@srcsip.UUCP> <18037@cisunx.UUCP> <1861@internal.Apple.COM>
Reply-To: dale@boing.UUCP (Dale Luck)
Organization: Boing, Milpitas, Ca.
Lines: 36

In article <1861@internal.Apple.COM> lsr@Apple.COM (Larry Rosenstein) writes:
>In article <18037@cisunx.UUCP> ejkst@cisunx.UUCP (Eric J. Kennedy) writes:
>> For starters, there are the thousands of programs written before
>> multi-finder that don't know how to multitask.  This problem will
>
>The number of such programs is very small, since any reasonable program 
>will automatically make the right calls to yield the CPU.
>
>Larry

A very early version of exec had a Yield() call. This would give up
the cpu to whatever task was next in the Ready Q. I used it for cpu
bound demos that I did not want to be cpu bound if there was other
things going on.

I think an additional style of sheduling is needed on the Amiga.
Right now every process that hogs the cpu gets about 4 time slices
or roughly 60msec before giving up the cpu to the next process. Just
like we can adjust the process priority of a task, I would like to
adjust the amount of time a cpu bound taskj gets before forcing it
to yield to the next Ready Task.

So not only would I lower the priority of background tasks but I
would also set their max time slice to something like 1 so that
anything else running at the same priority but having a larger time
slice allocated to it would get more time. This is true for even
foreground tasks, which all seem to run a priority 0. Being able to
adjust the amount of time spent on "equal priority" tasks would improve
the responsiveness of the Amiga. Possible even add a dynamic unix
like schedular that would adjust the time slice of a task based on
the amount of time it has already used up.


-- 
Dale Luck     GfxBase/Boing, Inc.
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