From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933282AbXC3F1u (ORCPT ); Fri, 30 Mar 2007 01:27:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933307AbXC3F1u (ORCPT ); Fri, 30 Mar 2007 01:27:50 -0400 Received: from canuck.infradead.org ([209.217.80.40]:40119 "EHLO canuck.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933282AbXC3F1t (ORCPT ); Fri, 30 Mar 2007 01:27:49 -0400 Date: Thu, 29 Mar 2007 22:26:07 -0700 From: Greg KH To: Kay Sievers , linux-kernel@vger.kernel.org Subject: Re: new sysfs layout and ethernet device names Message-ID: <20070330052607.GA26835@kroah.com> References: <20070320170102.GA16341@nostromo.devel.redhat.com> <3ae72650703220147j42db8f79s734d4755c2fa43fd@mail.gmail.com> <20070328031743.GA11819@nostromo.devel.redhat.com> <20070328041005.GA7550@kroah.com> <20070329004138.GA23562@nostromo.devel.redhat.com> <20070330023104.GA21771@kroah.com> <20070330032905.GA4384@nostromo.devel.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070330032905.GA4384@nostromo.devel.redhat.com> User-Agent: Mutt/1.5.14 (2007-02-12) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 29, 2007 at 11:29:05PM -0400, Bill Nottingham wrote: > Greg KH (greg@kroah.com) said: > > > If interfaces have to change, so be it. But changing the rules for > > > using them years after it's implemented and then claiming "you didn't > > > read the instructions" is pretty lame. > > > > That documentation has been in the kernel tree for almost a full year: > > It has a date on it. I'm not blind. That doesn't change the fact that > that documentation: > > > Date: Thu Apr 27 14:10:12 2006 -0700 > > postdates the interface it's describing by at *least* two years. Which > was the point of my mail that you conveniently ignored - retroactively > deciding which parts of the interface you export to userspace shouldn't be > used falls way short of best practices. I am not disagreeing with that, that is why the config option is present. > > Anyway, yes, older code should still "just work" if you enable the > > CONFIG_SYSFS_DEPRECATED config option in the kernel, that is what it is > > there for. > > It appears to... the point was that (as far as the code is concerned) > it's a silent break. Of course, code that expects the 'current' layout > will then break when this new change is made, unless you add > CONFIG_SYSFS_SLIGHTLY_LESS_DEPRECATED? Well, the idea is that over time, older things will move under this config option. If you disable it, you will have a "cleaner" sysfs tree, but if you enable it, it should all just look the same. Now some people have proposed versioning the sysfs interface (1, 2, 3, etc.) and have a config option for that. I don't know if that's really necessary just yet, but am considering it for future changes. thanks, greg k-h