*BSD News Article 27694


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From: terry@cs.weber.edu (Terry Lambert)
Newsgroups: comp.os.386bsd.development
Subject: Re: Notes on the *new* FreeBSD V1.1 VM system
Date: 22 Feb 1994 23:18:52 GMT
Organization: Weber State University, Ogden, UT
Lines: 23
Message-ID: <2ke3ss$l0d@u.cc.utah.edu>
References: <BcxpGux.dysonj@delphi.com> <MYCROFT.94Feb20102534@duality.gnu.ai.mit.edu> <CLL9J6.FCF@endicor.com>
NNTP-Posting-Host: cs.weber.edu

In article <CLL9J6.FCF@endicor.com> tsarna@endicor.com (Ty Sarna) writes:
>Is there any reason why memory allocation can't simply fail when there
>isn't any more to allocate? Sure, lots of unix software is going to
>kill itself off anyway dereferencing NULL pointers, but it at least
>gives those who care to check return values a chance to avoid
>catastrophe. 

This is an inevitable consequence of any system that does memory overcommit
(thus allowing you to run more processes than you are allowed to run).

I occasionally rail about the evils of memory overcommit, but in the end
I am usually shouted down (mostly by people who don't want to spend the
extra disk required for swap space).

Personally, I think you should be required to rebuild a kernel with
"option FAST_AND_LOOSE" if you want overcommit enabled.


					Terry Lambert
					terry@cs.weber.edu
---
Any opinions in this posting are my own and not those of my present
or previous employers.