Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!seismo!elsie!ado
From: ado@elsie.UUCP (Arthur David Olson)
Newsgroups: net.unix-wizards
Subject: brk's zero-fill behavior on VAXen
Message-ID: <7208@elsie.UUCP>
Date: Sun, 2-Nov-86 21:09:11 EST
Article-I.D.: elsie.7208
Posted: Sun Nov  2 21:09:11 1986
Date-Received: Tue, 4-Nov-86 01:40:53 EST
Organization: NIH-LEC, Bethesda, MD
Lines: 14

In section 2 of the UNIX Programmer's Manual, the description of the "brk" and
"sbrk" calls note only that they change the system's notion of the lowest
location not used by the program.  If the result of the call is to expand the
address space of the process, there's no promise about the contents of the
newly-available address space.  Yet on our VAX (and on yours, too, if you
have one) the newly-available space is always zero filled.

Can system performance be improved by avoiding zero filling of the new
memory?
--
UNIX is a registered trademark of AT&T.
--
	UUCP: ..decvax!seismo!elsie!ado   ARPA: elsie!ado@seismo.ARPA
	DEC, VAX, Elsie & Ado are Digital, Borden & Ampex trademarks.