Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.3 4.3bsd-beta 6/6/85; site well.UUCP
Path: utzoo!linus!decvax!decwrl!amdcad!lll-crg!well!fnf
From: fnf@well.UUCP (Fred Fish)
Newsgroups: net.emacs
Subject: Re: Gnu use of alloca and setjmp
Message-ID: <438@well.UUCP>
Date: Tue, 7-Jan-86 13:30:07 EST
Article-I.D.: well.438
Posted: Tue Jan  7 13:30:07 1986
Date-Received: Wed, 8-Jan-86 20:47:37 EST
References: <578@harvard.UUCP> <5140001@acf4.UUCP> <145@newton.ARPA>
Reply-To: fnf@well.UUCP (Fred Fish)
Organization: Whole Earth 'Lectronic Link, Sausalito, CA
Lines: 19

In article <145@newton.ARPA> crl@newton.UUCP (LaBrec) writes:
>The big advantage of using unexec over a dump/reload of memory is that 
>unexec puts some of the initialized areas into text space, thus making
>about 200 KB of memory sharable among all the users of GNU emacs.

This is only true for systems where data starts immediately after text.
In a very large number of cases, MMU braindamage dictates that there 
be a significant gap in the address space, between end of text and
start of data.  GNU emacs basically shoves things into text space by
extending it to overlap part of the data space.  If you have a 4Mb
"hole" between text and data, you end up with a VERY large shared 
text program!

-Fred
-- 

===============================================================================
Fred Fish  (415) 644-1230 ext 242  ucbvax!unisoft!fnf  well!fnf
===============================================================================