Subject: Re: Swap overcommit (was Re: Replacement for grep(1) (part 2))
To: Jason Thorpe <>
From: Matthew Jacob <>
List: tech-userlevel
Date: 07/13/1999 17:12:08
> On Tue, 13 Jul 1999 16:56:26 -0700 (PDT) 
>  Matthew Dillon <> wrote:
>  >     You have to consider the probability of an event occuring, not just
>  >     the possibility that the event might occur.  If the probability is 
>  >     one in a million years, then it is not something you need to worry
>  >     about relative to other things that, perhaps, you *should* be worrying
>  >     about.
> Having been a systems programmer and systems administrator at a
> university computer science department, dealing with large (well,
> they were large back then :-) systems where 60 students log in

That's not very large and wasn't back then either, even for low budget
hardware. We ran 33 users on a 128KB PDP 11/45 when I worked at Sidereal
in Portland (and people who attempted to use vi were taken out behind the
woodshed and dealt with).

> simultaneously to do their "Data Structures in C++" homework, I
> can guarantee you that the probability that someone else's buggy
> program will kill your unrelated application is a lot more than
> "once in a million years".

The purpose of a multiprogramming OS is to keep this from happening. If it
happens, you've incorrectly configured the OS or the OS needs some
rethinking. As a general rule.

This discussion has begun to really be unproductive. But it was
interesting to see that it occurred at all.