From owner-freebsd-hackers  Wed Jun 21 14:57:14 1995
Return-Path: hackers-owner
Received: (from majordom@localhost)
 From owner-freebsd-hackers  Wed Jun 21 16:20:25 1995
Return-Path: hackers-owner
Received: (from majordom@localhost)
          by freefall.cdrom.com (8.6.10/8.6.6) id QAA12452
          for hackers-outgoing; Wed, 21 Jun 1995 16:20:25 -0700
Received: from linux4nn.iaf.nl (root@linux4nn.iaf.nl [193.67.144.34])
          by freefall.cdrom.com (8.6.10/8.6.6) with ESMTP id QAA12446
          for <freebsd-hackers@freebsd.org>; Wed, 21 Jun 1995 16:20:19 -0700
Received: from uni4nn.iaf.nl (root@uni4nn.iaf.nl [193.67.144.33]) by linux4nn.iaf.nl (8.6.9/8.6.9) with SMTP id BAA08951; Thu, 22 Jun 1995 01:34:14 +0200
Received: by uni4nn.iaf.nl with UUCP id AA11150
  (5.67b/IDA-1.5); Thu, 22 Jun 1995 01:20:26 +0100
Received: by iafnl.iaf.nl with UUCP id AA18227
  (5.65c/IDA-1.4.4); Wed, 21 Jun 1995 22:56:39 +0200
Received: (from wilko@localhost) by yedi.iaf.nl (8.6.8/8.6.6) id SAA03739; Wed, 21 Jun 1995 18:59:44 +0200
From: Wilko Bulte <wilko@yedi.iaf.nl>
Message-Id: <199506211659.SAA03739@yedi.iaf.nl>
Subject: Re: freebsd and memory
To: davidg@root.com
Date: Wed, 21 Jun 1995 18:59:43 +1596657 (MET DST)
Cc: graichen@sirius.physik.fu-berlin.de, freebsd-hackers@freebsd.org
In-Reply-To: <199506202033.NAA02393@corbin.Root.COM> from "David Greenman" at Jun 20, 95 01:33:14 pm
X-Mailer: ELM [version 2.4 PL22]
Content-Type: text
Content-Length: 952       
Sender: hackers-owner@freebsd.org
Precedence: bulk

>    Yes, FreeBSD uses demand paging for all mapped file operations. This
> includes shared libraries as well as regular binaries. The main reason that
> Linux uses less memory is that they go to great lengths to order the routines
> in the shared libraries to reduce the sparseness of accesses for typical
> programs. This results in fewer page faults and less memory consumption when
> a small set of of programs are involved.

It might be interesting to know that at least AT&T V3.2 used the same approach
(i.e. reordering) on the shared libs. This had me stumped for a while when
I first saw it (years ago) but on second thoughts it might pay off.

WB
_     __________________________________________________________________________
 |   / o / /  _   Wilko Bulte             email: wilko@yedi.iaf.nl
 |/|/ / / /( (_)  Private FreeBSD site  - Arnhem - The Netherlands
--------------------------------------------------------------------------------