From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754704AbYIWSvE (ORCPT ); Tue, 23 Sep 2008 14:51:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753563AbYIWSuv (ORCPT ); Tue, 23 Sep 2008 14:50:51 -0400 Received: from mail.suse.de ([195.135.220.2]:51876 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751510AbYIWSuv (ORCPT ); Tue, 23 Sep 2008 14:50:51 -0400 Date: Tue, 23 Sep 2008 20:50:48 +0200 Message-ID: From: Takashi Iwai To: "Chris Li" Cc: "Giacomo A. Catenazzi" , "Mauro Carvalho Chehab" , "Steven Rostedt" , linux-kernel@vger.kernel.org Subject: Re: diet-kconfig: a script to trim unneeded kconfigs In-Reply-To: <70318cbf0809231115r506db98etd87b67a590ba6eae@mail.gmail.com> References: <20080918122541.2c3c7b39@areia.chehab.org> <48D27734.3040600@cateee.net> <48D36D02.4090003@cateee.net> <70318cbf0809191655m89e4b4fo68c3693487afed98@mail.gmail.com> <70318cbf0809221225i5be0ce6eh3ac09d8bf61cc2d7@mail.gmail.com> <70318cbf0809231115r506db98etd87b67a590ba6eae@mail.gmail.com> User-Agent: Wanderlust/2.12.0 (Your Wildest Dreams) SEMI/1.14.6 (Maruoka) FLIM/1.14.7 (=?ISO-8859-4?Q?Sanj=F2?=) APEL/10.6 Emacs/22.2 (x86_64-suse-linux-gnu) MULE/5.0 (SAKAKI) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org At Tue, 23 Sep 2008 11:15:19 -0700, Chris Li wrote: > > On Tue, Sep 23, 2008 at 4:31 AM, Takashi Iwai wrote: > > That is true. Enabling arbitrary kernel config item is hard to > > achieve right now. I think this feature should be implemented in > > kbuild parser itself. The current reverse-select is way limited and > > known to be problematic in many kernel configs. > > I was looking at the kbuild system. BTW, I really like the Makefile > in kbuild. For the reverse select, here is what I have in mind. > > The reverse select needs to maintain the define-user chain for > each kernel option. And each kernel option has a list of the kernel > option and value pare to enable an option. Once we produce such > an list for "all config". We can know exactly what kernel option > needs to set in order to get to so module. It is kind of doing > the data flow analyze on the config options. > > It is not trivial, but it shouldn't be too hard either. Well, it is not so easy, too. The good-working reverse selection with dependency checks is a feature we've long for in Kconfig, but it hasn't been implemented because it could easily introduce a messy dependency loop, or some cases are not easily resolvable. Anyway, the development of reverse-selection should involve with Sam and other Kbuild maintainer/developers. Takashi