From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966339AbWKTWJw (ORCPT ); Mon, 20 Nov 2006 17:09:52 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S966381AbWKTWJv (ORCPT ); Mon, 20 Nov 2006 17:09:51 -0500 Received: from hancock.steeleye.com ([71.30.118.248]:39069 "EHLO hancock.sc.steeleye.com") by vger.kernel.org with ESMTP id S966339AbWKTWJu (ORCPT ); Mon, 20 Nov 2006 17:09:50 -0500 Subject: Re: how to handle indirect kconfig dependencies From: James Bottomley To: Randy Dunlap Cc: lkml , zippel@linux-m68k.org In-Reply-To: <20061116200741.fb607fe4.randy.dunlap@oracle.com> References: <20061116200741.fb607fe4.randy.dunlap@oracle.com> Content-Type: text/plain Date: Mon, 20 Nov 2006 16:09:31 -0600 Message-Id: <1164060571.2816.106.camel@mulgrave.il.steeleye.com> Mime-Version: 1.0 X-Mailer: Evolution 2.6.3 (2.6.3-1.fc5.5) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2006-11-16 at 20:07 -0800, Randy Dunlap wrote: > Hi, > > I have a (randconfig) build of 2.6.19-rc5-mm2 with: > > CONFIG_DEBUG_READAHEAD=y > > which selects DEBUG_FS, so DEBUG_FS=y, but DEBUG_FS depends on > SYSFS, and SYSFS is not set in the randconfig. > > This randconfig causes this build error: > > fs/built-in.o: In function `debugfs_init': > inode.c:(.init.text+0xdb2): undefined reference to `kernel_subsys' > > so the question is: > (How) can kconfig follow the dependency chain and either > - prevent this odd config combination or > - see that 'select DEBUG_FS' implies 'select SYSFS' and then enable SYSFS > ? > > I don't believe that the right answer is to add > depends on SYSFS > to DEBUG_READAHEAD. > > > .config is at http://oss.oracle.com/~rdunlap/configs/config-readahead-debugfs Actually, no, I don't think this is the right thing to do. If we can't persuade selected CONFIG options to give an inherited dependency to the selectee, then the only other option is to make sure that selectable config options have no dependencies (i.e. they select everything they need). James