From owner-freebsd-current Mon Apr 24 8:57:42 2000 Delivered-To: freebsd-current@freebsd.org Received: from tinker.exit.com (exit-gw.power.net [207.151.46.196]) by hub.freebsd.org (Postfix) with ESMTP id A107737BB08 for ; Mon, 24 Apr 2000 08:57:36 -0700 (PDT) (envelope-from frank@exit.com) Received: from realtime.exit.com (realtime.exit.com [206.223.0.5]) by tinker.exit.com (8.9.3/8.9.3) with ESMTP id IAA80392; Mon, 24 Apr 2000 08:57:31 -0700 (PDT) (envelope-from frank@exit.com) Received: (from frank@localhost) by realtime.exit.com (8.9.3/8.9.3) id IAA13657; Mon, 24 Apr 2000 08:57:30 -0700 (PDT) (envelope-from frank) From: Frank Mayhar Message-Id: <200004241557.IAA13657@realtime.exit.com> Subject: Re: SMP changes and breaking kld object module compatibility In-Reply-To: <00042409270400.09338@nomad.dataplex.net> from Richard Wackerbarth at "Apr 24, 2000 09:27:04 am" To: Richard Wackerbarth Date: Mon, 24 Apr 2000 08:57:30 -0700 (PDT) Cc: Kenneth Wayne Culver , freebsd-current@FreeBSD.ORG Reply-To: frank@exit.com Organization: Exit Consulting X-Copyright0: Copyright 2000 Frank Mayhar. All Rights Reserved. X-Copyright1: Permission granted for electronic reproduction as Usenet News or email only. X-Mailer: ELM [version 2.4ME+ PL68 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Richard Wackerbarth wrote: > On a released system, I may not have the sources to recompile the module. > It might be a proprietary module that I got with the hardware, for example. > That is why STABLE INTERFACES are so IMPORTANT to USERS. > > "Current" is a sandbox. Lower expectations are part of that game. > But released systems are stone houses, not sandcastles. On the _other_ hand: 1. 4.0 hasn't been out long enough for there to be any significant support for it in proprietary systems. It takes more lead time than this. 2. Significant enhancements are often worth the price in needing to rebuild modules. The SMP fixes are quite significant and, IMHO, are very worth the possible short-term instability induced by them. (Although it looks like they're quite stable.) Consider me a customer that is very interested in these fixes even though my bread-and-butter system will need to be rebuilt. 3. Any proprietary module that depends so heavily upon kernel internals is, IMNSHO, broken by definition. If one is writing a proprietary module, particularly for an open-source system, one should write to the lowest common denominator and _not_ to internal interfaces that could change out from under you at any moment. 4. No system, released or otherwise, is a "stone house." At best it's a wooden house (to use your terminology), since defect fixes might require changes to internal interfaces. I know, I do this for a living. 5. The SMP stuff is about _internal_ interfaces, not external ones. External interfaces are the ones that are fixed in any OS, not the internal ones. Otherwise, how do we make progress? The Linux ABI, btw (to refer to your previous message on the subject), is a set of _external_ interfaces, not internal ones. Number six is probably better unsaid. -- Frank Mayhar frank@exit.com http://www.exit.com/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message