Subject: Re: Replacement for grep(1) (part 2)
To: Jason Thorpe <thorpej@nas.nasa.gov>
From: Matthew Dillon <dillon@apollo.backplane.com>
List: tech-userlevel
Date: 07/13/1999 15:44:40
:On Tue, 13 Jul 1999 15:12:14 -0700 (PDT)
: Matthew Dillon <dillon@apollo.backplane.com> wrote:
:
: > The text size of a program is irrelevant, because swap is never
: > allocated for it. The data and BSS are only relevant when they
: > are modified.
:
:Bzzt. BSS is relevant when accessed (at least in NetBSD).
True enough, though that is something we could fix under FreeBSD. Also
irrelevant... anything that causes a page fault and allocates a page
is effectively what we are talking about.
:...and as I recall, those SGIs at BEST were general-purpose computing
:environments. Chris already said that disallowing overcommit wasn't
:necessarily appropriate in every situation. So make it a knob. Big
:deal. Everyone has what they want.
:
: -- Jason R. Thorpe <thorpej@nas.nasa.gov>
So far nobody has been able to justify any good reasons for adding it
to the system. I'm sorry, but just throwing out worst-case theories
is not a good justification, nor is throwing embedded systems into the
fray - because those already have to control memory fairly tightly
and there are plenty of ways of doing that without having to do
in-kernel reservation. Throwing generic 'critical servers' into the
fray also isn't appropriate, because any server that is that critical
also implements its own memory alloction management. It has to in
order to guarentee performance and performance will degrade before
one runs out of memory.
-Matt
Matthew Dillon
<dillon@backplane.com>