Path: utzoo!utgpu!water!watmath!clyde!bellcore!decvax!ucbvax!agate!ig!uwmcsd1!bbn!rochester!ur-tut!sunybcs!ugpete
From: ugpete@sunybcs (Peter Theobald)
Newsgroups: comp.sys.amiga
Subject: AmigaDos don't thrash no more!
Message-ID: <8504@sunybcs.UUCP>
Date: 12 Feb 88 22:02:18 GMT
Sender: nobody@sunybcs.UUCP
Reply-To: ugpete@sunybcs.UUCP (Peter Theobald)
Organization: SUNY/Buffalo Computer Science
Lines: 23

<Line Eater Motel. Line eaters check in.... but they don't check out!>

AmigaDos should sort disk requests by track. This way if three processes
ask for three different files scattered all over the disk, instead of
jumping around like a Tasmianian Devil getting blocks from first one
file, then the other then back to the first, AmigaDos would load in the
blocks on the tracks currently nearest the read head. Then it would move
the head to the next track with requested data on it, etc... It could
continue this process sweeping the head back and forth across the disk
picking up what is needed, wasting the least amount of time.
	This would eliminate thrashing, and would speed up disk accesses
to boot! I think this is similar to what a clone of Peter da Silva meant by
single-threading loadSegs.
	How major a change in AmigaDog is this?

	-Pete



Peter Theobald				SUNY/Buffalo Computer Science
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