Subject: Re: Replacement for grep(1) (part 2)
To: Jason Thorpe <thorpej@nas.nasa.gov>
From: Neil A. Carson <neil@causality.com>
List: tech-userlevel
Date: 07/13/1999 15:12:43
Jason Thorpe wrote:
> 
> On Tue, 13 Jul 1999 14:14:52 -0700 (PDT)
>  Matthew Dillon <dillon@apollo.backplane.com> wrote:
> 
>  >     If you don't have the disk necessary for a standard overcommit model to
>  >     work, you definitely do not have the disk necessary for a non-overcommit
>  >     model to work.

> from userspace.  That way, my correctly written program can take appropriate
> action (like, say, invoke its type-stable memory pool garbage collector, and
> try again).
> 
> Right now, BSD doesn't do this, and that makes creating a truly reliable
> system *very hard*.

John Dyson changed NCOS (which runs on swapless systems) for a behaviour
whereby memory was accounted much more strictly and monitored by a
background process on the desktop. When the 'statistical conditions'
(which take partially into account memory that could be reaped by the
pagedaemon, etc) get to a 'yellow' state, the desktop monitor asks
applications to close themselves. Especially with ref to JVMs etc, this
took a very long time to get right.

	Neil