From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from xsmtp1.ethz.ch ([82.130.70.13]:25844 "EHLO xsmtp1.ethz.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756465AbYCTPiV (ORCPT ); Thu, 20 Mar 2008 11:38:21 -0400 Message-ID: <47E2811B.9000100@debian.org> Date: Thu, 20 Mar 2008 16:22:03 +0100 From: "Giacomo A. Catenazzi" MIME-Version: 1.0 Subject: Re: The evolution of the Linux kernel build system References: <9048849A-9578-40E7-BD0E-FF2CD34F9372@ugent.be> In-Reply-To: <9048849A-9578-40E7-BD0E-FF2CD34F9372@ugent.be> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kbuild-owner@vger.kernel.org List-ID: To: Bram Adams Cc: linux-kbuild@vger.kernel.org Bram Adams wrote: > We would like to thank Sam Ravnborg and Kai Germaschewski for their > constructive comments on an earlier version of the report. Any feedback > on the published report or suggestions for further analysis are gladly > appreciated. Now I've done only a quick look. I think you missed a point about dependencies. Also in the old method, the .h dependencies were calculated on build time (with the gcc -MM option IIRC). But big problem is the dependencies of configuration. Instead of having the dependency of config.h, the kbuild checks about changes on every single configuration item. So "make dep" read the sources looking for CONFIG_ options. IIRC it was a separate step, not to check file for CONFIG_ string at every modification. "make dep" was not so mandatory after every patch, and anyway before big releases a "make mrproper" was still recommended. There was a lot of active development on this program, to increment speed, and AFAIK no other project split header dependencies in a more precise way. This weekend I'll read carefully the paper and I'll give you more comments. ciao cate