From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765578AbYDYXe4 (ORCPT ); Fri, 25 Apr 2008 19:34:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756931AbYDYXeq (ORCPT ); Fri, 25 Apr 2008 19:34:46 -0400 Received: from agminet01.oracle.com ([141.146.126.228]:15999 "EHLO agminet01.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756525AbYDYXep (ORCPT ); Fri, 25 Apr 2008 19:34:45 -0400 Date: Fri, 25 Apr 2008 16:33:48 -0700 From: Randy Dunlap To: lkml Cc: samr , akpm , torvalds Subject: [PATCH] documentation: remove smart-config.txt Message-Id: <20080425163348.a030dc7a.randy.dunlap@oracle.com> Organization: Oracle Linux Eng. X-Mailer: Sylpheed 2.4.7 (GTK+ 2.8.10; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Brightmail-Tracker: AAAAAQAAAAI= X-Brightmail-Tracker: AAAAAQAAAAI= X-Whitelist: TRUE X-Whitelist: TRUE Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Randy Dunlap As requested by Sam Ravnborg: Remove Documentation/smart-config.txt. It is outdated and has been (functionally) replaced by Documentation/kbuild/*.txt. Signed-off-by: Randy Dunlap --- Documentation/smart-config.txt | 98 ------------------------------- 1 file changed, 98 deletions(-) --- linux-2.6.25-git7.orig/Documentation/smart-config.txt +++ /dev/null @@ -1,98 +0,0 @@ -Smart CONFIG_* Dependencies -1 August 1999 - -Michael Chastain -Werner Almesberger -Martin von Loewis - -Here is the problem: - - Suppose that drivers/net/foo.c has the following lines: - - #include - - ... - - #ifdef CONFIG_FOO_AUTOFROB - /* Code for auto-frobbing */ - #else - /* Manual frobbing only */ - #endif - - ... - - #ifdef CONFIG_FOO_MODEL_TWO - /* Code for model two */ - #endif - - Now suppose the user (the person building kernels) reconfigures the - kernel to change some unrelated setting. This will regenerate the - file include/linux/autoconf.h, which will cause include/linux/config.h - to be out of date, which will cause drivers/net/foo.c to be recompiled. - - Most kernel sources, perhaps 80% of them, have at least one CONFIG_* - dependency somewhere. So changing _any_ CONFIG_* setting requires - almost _all_ of the kernel to be recompiled. - -Here is the solution: - - We've made the dependency generator, mkdep.c, smarter. Instead of - generating this dependency: - - drivers/net/foo.c: include/linux/config.h - - It now generates these dependencies: - - drivers/net/foo.c: \ - include/config/foo/autofrob.h \ - include/config/foo/model/two.h - - So drivers/net/foo.c depends only on the CONFIG_* lines that - it actually uses. - - A new program, split-include.c, runs at the beginning of - compilation (make bzImage or make zImage). split-include reads - include/linux/autoconf.h and updates the include/config/ tree, - writing one file per option. It updates only the files for options - that have changed. - -Flag Dependencies - - Martin Von Loewis contributed another feature to this patch: - 'flag dependencies'. The idea is that a .o file depends on - the compilation flags used to build it. The file foo.o has - its flags stored in .flags.foo.o. - - Suppose the user changes the foo driver from resident to modular. - 'make' will notice that the current foo.o was not compiled with - -DMODULE and will recompile foo.c. - - All .o files made from C source have flag dependencies. So do .o - files made with ld, and .a files made with ar. However, .o files - made from assembly source do not have flag dependencies (nobody - needs this yet, but it would be good to fix). - -Per-source-file Flags - - Flag dependencies also work with per-source-file flags. - You can specify compilation flags for individual source files - like this: - - CFLAGS_foo.o = -DSPECIAL_FOO_DEFINE - - This helps clean up drivers/net/Makefile, drivers/scsi/Makefile, - and several other Makefiles. - -Credit - - Werner Almesberger had the original idea and wrote the first - version of this patch. - - Michael Chastain picked it up and continued development. He is - now the principal author and maintainer. Please report any bugs - to him. - - Martin von Loewis wrote flag dependencies, with some modifications - by Michael Chastain. - - Thanks to all of the beta testers.