From owner-freebsd-questions@FreeBSD.ORG Wed Sep 3 09:58:49 2003 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 824EB16A4BF for ; Wed, 3 Sep 2003 09:58:49 -0700 (PDT) Received: from pop017.verizon.net (pop017pub.verizon.net [206.46.170.210]) by mx1.FreeBSD.org (Postfix) with ESMTP id 6D50D43F75 for ; Wed, 3 Sep 2003 09:58:48 -0700 (PDT) (envelope-from cswiger@mac.com) Received: from mac.com ([68.237.14.199]) by pop017.verizon.net (InterMail vM.5.01.05.33 201-253-122-126-133-20030313) with ESMTP id <20030903165847.ZPOC27671.pop017.verizon.net@mac.com> for ; Wed, 3 Sep 2003 11:58:47 -0500 Message-ID: <3F561DB9.7050201@mac.com> Date: Wed, 03 Sep 2003 12:58:33 -0400 From: Chuck Swiger Organization: The Courts of Chaos User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.4) Gecko/20030624 X-Accept-Language: en-us, en MIME-Version: 1.0 Cc: freebsd-questions@freebsd.org References: <3F55680A.2070007@princeton.edu> <200309031707.21584.malcolm.kay@internode.on.net> In-Reply-To: <200309031707.21584.malcolm.kay@internode.on.net> X-Enigmail-Version: 0.76.5.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Authentication-Info: Submitted using SMTP AUTH at pop017.verizon.net from [68.237.14.199] at Wed, 3 Sep 2003 11:58:47 -0500 Subject: Re: .ko files in /boot/kernel X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 03 Sep 2003 16:58:49 -0000 Malcolm Kay wrote: [ ... ] > But; how much memory do you have? Your kernel is about 2Mb smaller > than the one I'm using but the difference represents about 0.4% of my total > memory which I suspect is almost always incompletely used. > > Could I ever see [any] effective difference with an "optimised kernel"? Yes, although the difference is likely to not be noticable for most tasks. However, saving memory is sort of like reducing the amount that a bicycle weighs. A difference of a few hundred grams won't be noticable most of the time compared with ~50 kg of the rider+bike, but for some trips-- particularly over the long hau;-- every little bit helps. There's more to the analogy: reducing the size of the kernel is more useful than saving memory elsewhere in much the same way that reducing the weight of bicycle tires counts more than reducing the weight of the frame. Reducing tire weight affects not just total mass but the amount of rotational interia as well. Reducing the size of the kernel rather than some random userland process (like /bin/sh) reduces the amount of wired down memory and saves KVA. -- -Chuck