Path: utzoo!mnetor!uunet!seismo!sundc!pitstop!sun!pepper!cmcmanis
From: cmcmanis%pepper@Sun.COM (Chuck McManis)
Newsgroups: comp.sys.amiga
Subject: Re: AmigaDos don't thrash no more!
Message-ID: <42382@sun.uucp>
Date: 18 Feb 88 17:57:46 GMT
References: <8504@sunybcs.UUCP> <3247@watcgl.waterloo.edu> <8626@sunybcs.UUCP>
Sender: news@sun.uucp
Reply-To: cmcmanis@sun.UUCP (Chuck McManis)
Organization: Sun Microsystems, Mountain View
Lines: 16

In article <8626@sunybcs.UUCP> ugpete@joey.UUCP (Peter Theobald) writes:
|>No, that wouldn't cause starvation. The disk would service every request on
|>cylinders 0 - 79 in that order, and then service every request on tracks
|>79 - 0 in that order (or however # of cylinders there are). This process
|>would repeat until there are no more requests. A request cannot be starved
|>because it must at most wait for the head to travel to one extreme and back.

But if the algorithim is not to smart then a program banging on track 79
will affect the read latency time of the program that is trying to read
track 0. Probably not killer but it does add an artifact to the scheduling
algorithim and make programs with scattered data run slower than programs
with localized data.

--Chuck McManis
uucp: {anywhere}!sun!cmcmanis   BIX: cmcmanis  ARPAnet: cmcmanis@sun.com
These opinions are my own and no one elses, but you knew that didn't you.