From owner-freebsd-smp Thu Jun 22 11:17:39 2000 Delivered-To: freebsd-smp@freebsd.org Received: from smtp01.primenet.com (smtp01.primenet.com [206.165.6.131]) by hub.freebsd.org (Postfix) with ESMTP id C852737BE95 for ; Thu, 22 Jun 2000 11:17:35 -0700 (PDT) (envelope-from tlambert@usr08.primenet.com) Received: (from daemon@localhost) by smtp01.primenet.com (8.9.3/8.9.3) id LAA01938; Thu, 22 Jun 2000 11:17:25 -0700 (MST) Received: from usr08.primenet.com(206.165.6.208) via SMTP by smtp01.primenet.com, id smtpdAAALkayac; Thu Jun 22 11:15:27 2000 Received: (from tlambert@localhost) by usr08.primenet.com (8.8.5/8.8.5) id LAA06872; Thu, 22 Jun 2000 11:15:23 -0700 (MST) From: Terry Lambert Message-Id: <200006221815.LAA06872@usr08.primenet.com> Subject: Re: source control (Was Re: SMP discussion moving to freebsd-smp) To: adsharma@sharmas.dhs.org Date: Thu, 22 Jun 2000 18:15:23 +0000 (GMT) Cc: tlambert@primenet.com, smp@freebsd.org In-Reply-To: <200006220525.WAA29645@sharmas.dhs.org> from "Arun Sharma" at Jun 21, 2000 10:25:15 PM X-Mailer: ELM [version 2.5 PL2] MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-smp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org > > Too bad the source code control tool that FreeBSD uses doesn't > > support multiple lines of developement. > > AFAIK, you can have multiple branches in cvs. You probably meant, it > doesn't support multiple lines of developement _well_ ? Or am I > overlooking some obvious shortcoming of cvs ? > > At work, we use perforce. The nice thing (which cvs doesn't have) > about it is that it has a concept of a changeset. This is equivalent to what Larry McVoy calls "an LOD" or "Line Of Developement". The problem with CVS is reconciliation of lines of developement with the HEAD branch. To make this work, you have to consider each LOD as a container for historical LODs, and the winning code for any given problem would propagate up to the "HEAD" -- the top level in a hierarchy. The CVS model is HEAD-centric, which means that there is always "One True FreeBSD". From a Physics standpoint, you could see multiple LODs as an uncertainty wave that only collapses to particular code when an observer named "-RELEASE" looks at it. 8-). > Any extended discussion is off topic here, I think. I don't mind > offline email though :) It's actually appropriate for -arch, I think. Our tools constrain what we can implement more than our thinking does. For example, the linker set code in FreeBSD wasn't possible until it was supported by our tools; now we could not imagine going through the contortions not having them would require. I would even posit that some of the problems that are solved today using linker sets would not have been permitted to be solved, if it meant adding convoluted and difficult for a layman to understand code to accomplish the same ends. Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message