From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933175AbXH3Sid (ORCPT ); Thu, 30 Aug 2007 14:38:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932757AbXH3SiL (ORCPT ); Thu, 30 Aug 2007 14:38:11 -0400 Received: from ogre.sisk.pl ([217.79.144.158]:58437 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932662AbXH3SiJ (ORCPT ); Thu, 30 Aug 2007 14:38:09 -0400 From: "Rafael J. Wysocki" To: Hugh Dickins Subject: Re: CONFIG_HOTPLUG_CPU: kconfig bug? Date: Thu, 30 Aug 2007 20:48:55 +0200 User-Agent: KMail/1.9.5 Cc: Roman Zippel , Sam Ravnborg , Michal Piotrowski , linux-kernel@vger.kernel.org, kbuild-devel@lists.sourceforge.net References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200708302048.55793.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thursday, 30 August 2007 14:40, Hugh Dickins wrote: > On Thu, 30 Aug 2007, Roman Zippel wrote: > > > > > > > > I've noticed an oddity with CONFIG_HOTPLUG_CPU in 2.6.23-rc: > > > > > > make oldconfig seems to turn it on even when nothing wants it, > > > > > > increasing kernel size by about 10k; but if you then edit the > > > > > > line out of .config and make oldconfig again, it correctly > > > > > > offers the choice and lets it be turned off after all. > > > > It's somewhat a side effect of using select and defaults, the order of the > > config symbols becomes significant for oldconfig, if you look at the > > output you'll find: > > > > Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL) (HOTPLUG_CPU) [Y/?] y > > > > this sets it to 'y'. In this case one isn't asked about it, because there > > is only one choice. The patch below avoids the setting of the value here. > > Thanks for working that out: your patch certainly works for me, > and would be good to see in 2.6.23, to prevent lots of users getting > an unnecessary CONFIG_HOTPLUG_CPU forever after. I wonder what config > options this might have forced in the past. Probably CONFIG_SUSPEND, which was a new option, defaulted to 'y' and selected CONFIG_HOTPLUG_CPU indirectly, because CONFIG_SMP was set. Greetings, Rafael