Path: utzoo!attcan!uunet!world!esegue!Postmaster
From: johnl@iecc.cambridge.ma.us (John R. Levine)
Newsgroups: comp.arch
Subject: Re: automagic overlays?
Message-ID: <9011101515.AA23430@iecc.cambridge.ma.us>
Date: 10 Nov 90 20:15:12 GMT
Sender: Postmaster@iecc.cambridge.ma.us
Organization: I.E.C.C., Cambridge MA 02238
Lines: 13
In-Reply-To: <11043@pt.cs.cmu.edu>

In article <11043@pt.cs.cmu.edu> you write:
>Is anybody out there old enough to remember when we used overlays?

Sure.  I used them under PC-DOS in 1987.

My impression is that when paging is available, it usually performs much
better than overlays for two reasons:  one is that the need to overlay is
detected by hardware without having to test at each call, the other is that
getting a good structure to the overlay tree is hard enough that you're
better off letting the pager determine the actual working set.

Regards,
John Levine, johnl@iecc.cambridge.ma.us, {spdcc|ima|world}!esegue!johnl