From owner-freebsd-current@FreeBSD.ORG Tue Nov 18 16:22:39 2003 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id D486116A4CE for ; Tue, 18 Nov 2003 16:22:39 -0800 (PST) Received: from tx0.oucs.ox.ac.uk (tx0.oucs.ox.ac.uk [129.67.1.163]) by mx1.FreeBSD.org (Postfix) with ESMTP id EF19443F85 for ; Tue, 18 Nov 2003 16:22:32 -0800 (PST) (envelope-from colin.percival@wadham.ox.ac.uk) Received: from scan0.oucs.ox.ac.uk ([129.67.1.162] helo=localhost) by tx0.oucs.ox.ac.uk with esmtp (Exim 4.20) id 1AMG76-0006KJ-DA for current@freebsd.org; Wed, 19 Nov 2003 00:22:32 +0000 Received: from rx0.oucs.ox.ac.uk ([129.67.1.161]) by localhost (scan0.oucs.ox.ac.uk [129.67.1.162]) (amavisd-new, port 25) with ESMTP id 24178-04 for ; Wed, 19 Nov 2003 00:22:31 +0000 (GMT) Received: from gateway.wadham.ox.ac.uk ([163.1.161.253]) by rx0.oucs.ox.ac.uk with smtp (Exim 4.20) id 1AMG75-0006KE-2a for current@freebsd.org; Wed, 19 Nov 2003 00:22:31 +0000 Received: (qmail 5547 invoked by uid 0); 19 Nov 2003 00:22:31 -0000 Received: from colin.percival@wadham.ox.ac.uk by gateway by uid 71 with qmail-scanner-1.16 (sweep: 2.14/3.71. spamassassin: 2.53. Clear:. Processed in 1.404362 secs); 19 Nov 2003 00:22:31 -0000 X-Qmail-Scanner-Mail-From: colin.percival@wadham.ox.ac.uk via gateway X-Qmail-Scanner: 1.16 (Clear:. Processed in 1.404362 secs) Received: from dhcp1131.wadham.ox.ac.uk (HELO piii600.wadham.ox.ac.uk) (163.1.161.131) by gateway.wadham.ox.ac.uk with SMTP; 19 Nov 2003 00:22:30 -0000 Message-Id: <5.0.2.1.1.20031119000628.03199b18@popserver.sfu.ca> X-Sender: cperciva@popserver.sfu.ca X-Mailer: QUALCOMM Windows Eudora Version 5.0.2 Date: Wed, 19 Nov 2003 00:22:27 +0000 To: Scott Long , dyson@iquest.net From: Colin Percival In-Reply-To: <20031118164905.R35009@pooker.samsco.home> References: <200311182307.hAIN7Wpm000717@dyson.jdyson.com> <200311182307.hAIN7Wpm000717@dyson.jdyson.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed cc: current@freebsd.org Subject: Re: Unfortunate dynamic linking for everything X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 19 Nov 2003 00:22:40 -0000 At 17:06 18/11/2003 -0700, Scott Long wrote: >Our rationale for encouraging Gordon is as follows: > >1. 4.x upgrade path: As we approach 5-STABLE, a lot of users might want > to upgrade from 4-STABLE. Historically in 4.x, the / partition has > been very modest in size. One just simply cannot cram the bloat that > has grown in 5.x into a 4.x partition scheme. Of course there is the > venerable 'dump - clean install - restore' scheme, but we were looking > for something a little more user-friendly. Of course, making / dynamic results in added complication of removing old libraries from /usr/lib, now that some of them have moved to /lib... >3. Binary security updates: there is a lot of interest in providing a > binary update mechanism for doing security updates. Having a dynamic > root means that vulnerable libraries can be updated without having to > update all of the static binaries that might use them. As far as I'm concerned, this is a non-issue. Identifying which static binaries need to be replaced is now a solved problem, replacing them is easy, and if binary patches are used, there is effectively no impact on bandwidth usage either. On the issue of performance, however: I know people have benchmarked fork-bombs, but has anyone done benchmarks with moderate numbers of long-lived, library-intensive, processes? It seems to me that dynamic linking could have caching advantages. Colin Percival