From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754544Ab0CEHGc (ORCPT ); Fri, 5 Mar 2010 02:06:32 -0500 Received: from mail-fx0-f219.google.com ([209.85.220.219]:34379 "EHLO mail-fx0-f219.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753882Ab0CEHGa convert rfc822-to-8bit (ORCPT ); Fri, 5 Mar 2010 02:06:30 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; b=ifS9DlHbaGMODqORMmQOdfBlmZvvwLYEEnhrMaQ80dGOlEXQoXfOpTuRLB7CCHCPso EhZrWfSGTcBD2ZpbWw+hy0WW05qUGEUlz7MYGDS3+gf5ON4FGeRWiOmzFif5p0bzwjR8 zPggWyt7Ttu03LaoqhRCoqQnzg5hAsIpFooIo= MIME-Version: 1.0 In-Reply-To: <20100305064955.GA6453@elte.hu> References: <20100304103655.0b14343f@jbarnes-piketon> <20100304105624.70fe845e@jbarnes-piketon> <21d7e9971003041125x1aee3b3ew1e407ca6695e10fc@mail.gmail.com> <21d7e9971003041406n53d9cae0h53374abf3dca494e@mail.gmail.com> <1267748927.3496.6.camel@nisroch> <20100305064955.GA6453@elte.hu> Date: Fri, 5 Mar 2010 09:06:28 +0200 X-Google-Sender-Auth: ad748625d78e6cde Message-ID: <84144f021003042306w2e017efbva2be364c1c4980a7@mail.gmail.com> Subject: Re: [git pull] drm request 3 From: Pekka Enberg To: Ingo Molnar Cc: Ben Skeggs , Linus Torvalds , Dave Airlie , Dave Airlie , linux-kernel@vger.kernel.org, Jesse Barnes , dri-devel@lists.sf.net Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 5, 2010 at 8:49 AM, Ingo Molnar wrote: > The conclusion is crystal clear, breaking an ABI via a "flag day" > cleanup/feature/etc is: > >  - wrong > >  - harmful > >  - limits the developer base > >  - limits the tester base > >  - wastes time and effort. (fewer developers/testers means that while _this_ >   feature was easier to add, all your _future_ features will be a bit harder >   to do. It compounds up.) > >  - so it hurts even the very developer who is most convinced that this was the >   right thing to do > > It's a bad technical decision throughout. It's masochistic and often suicidal > to just about any project in essence. I've seen projects that did it once and > died just due to that single act of stupidity. I've seen projects that have > done it a few times and took the usage hit, limped along with the wounds and > never grew to the size they could have achieved. I've seen projects that did > it once, took the hit, learned from it and never did it again. Agreed. What bothers me in this discussion is that people keep bringing up the fact that nouveau is mostly developed by volunteers and thus it doesn't make sense to make sure it's backwards (or forwards) compatible. But the way I see it, it's the complete opposite. It's _more_ important to support ABIs for community-driven efforts because you're relying on people who by definition don't have time to waste. While the nouveau people might have good intentions, I'm afraid they might be severely limiting their developer and tester base because they're not focused on real world problems (like the ones Linus is seeing). Pekka