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From: breck@aimt.UUCP (Robert Breckinridge Beatie)
Newsgroups: comp.unix.wizards,comp.unix.questions
Subject: Re: ulimit's (was "Re: Another Annoying Microport Inquiry")
Message-ID: <99@aimt.UUCP>
Date: Wed, 7-Oct-87 12:52:58 EDT
Article-I.D.: aimt.99
Posted: Wed Oct  7 12:52:58 1987
Date-Received: Sat, 10-Oct-87 14:55:59 EDT
References: <1408@dasys1.UUCP> <6475@brl-smoke.ARPA> <926@sauron.Columbia.NCR.COM> <29928@sun.uucp>
Organization: AIM Technology, Palo Alto, CA
Lines: 19
Keywords: Microport patch ulimit break
Summary: ulimit and maximum break value
Xref: mnetor comp.unix.wizards:4757 comp.unix.questions:4443

In article <29928@sun.uucp>, guy%gorodish@Sun.COM (Guy Harris) writes:
> > 	[ comments that ulimit is used to prevent running out of swap]
> 
> Excuse me?  How can the limit on the maximum FILE size - which is what is being
> discussed here - have any direct effect on the consumption of swap space?

Actually, it's an understandable mistake.  On many systems ulimit() can be used
to find the maximum possible break value for the system.  For example on Plexus
system V systems, ulimit(3,0L) returns the maximum possible break value.  It's
not in the SVID but it is in enough implementations of unix that it's pretty
confusing.

Now for a question.  As I said, ulimit can be used to find the maximum possible
break value.  But ulimit can't set the maximum possible break value.  This
seems a perfectly reasonable extension.  Why can't the superuser change this
value for his process?  Does it complicate memory management too severely?
-- 
Breck Beatie
uunet!aimt!breck