From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763223AbYHDVQZ (ORCPT ); Mon, 4 Aug 2008 17:16:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758632AbYHDVQO (ORCPT ); Mon, 4 Aug 2008 17:16:14 -0400 Received: from smtpout3.tre.se ([80.251.192.228]:25602 "EHLO smtpout3.tre.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758764AbYHDVQN (ORCPT ); Mon, 4 Aug 2008 17:16:13 -0400 Date: Mon, 4 Aug 2008 23:16:41 +0200 From: Sam Ravnborg To: Jan Beulich Cc: mingo@elte.hu, Harvey Harrison , tglx@linutronix.de, Roman Zippel , Nick Piggin , linux-kernel@vger.kernel.org Subject: Re: def_bool n Message-ID: <20080804211640.GC29902@uranus.ravnborg.org> References: <48971232.76E4.0078.0@novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <48971232.76E4.0078.0@novell.com> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 04, 2008 at 01:29:06PM +0100, Jan Beulich wrote: > Could either of you clarify what the significance of such a construct > (encountered several times in arch/x86/Kconfig alone) is? > > At first, I noticed it only with GENERIC_LOCKBREAK (it is my > understanding that this block can go away entirely), but then realized > that with the bool->def_bool conversion this was introduced in various > other places (where "default n" was used before, which seems as > pointless a statement). Am I missing something? No. arch/x86/Kconfig: config GENERIC_LOCKBREAK def_bool n I assume this is solely to document that x86 does NOT use GENERIC_LOCKBREAK as it serves no other purpose. Notice that we may see: init/Kconfig: config FOO def_bool y arch/$ARCH/Kconfig: config FOO def_bool n And this will result in setting FOO to the last seen value. All the HAVE_* stuff is btw to avoid such double definition of a config symbol. GENERIC_LOCKBREAK is another candidate. Sam