From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754623Ab0ALQ1u (ORCPT ); Tue, 12 Jan 2010 11:27:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754566Ab0ALQ1b (ORCPT ); Tue, 12 Jan 2010 11:27:31 -0500 Received: from smtp1.linux-foundation.org ([140.211.169.13]:52068 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754544Ab0ALQ11 (ORCPT ); Tue, 12 Jan 2010 11:27:27 -0500 Date: Tue, 12 Jan 2010 08:26:22 -0800 (PST) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: Valdis.Kletnieks@vt.edu cc: Yinghai Lu , Suresh Siddha , "ananth@in.ibm.com" , Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH 2/4] x86: use dmi check to treat disabled cpus as hotplug cpus. In-Reply-To: <6686.1263312874@localhost> Message-ID: References: <1263264483-3959-1-git-send-email-yinghai@kernel.org> <1263264483-3959-4-git-send-email-yinghai@kernel.org> <6686.1263312874@localhost> User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 12 Jan 2010, Valdis.Kletnieks@vt.edu wrote: > > OK, I'll bite - how do you build an X86-64 kernel that doesn't have > CONFIG_HOTPLUG_CPU selected? Try as I might, even if I have PM_SLEEP=n, > PM_SLEEP_SMP insists on being set, and then selecting HOTPLUG_SMP. If that is true, then there is some bug in the kconfig parser. PM_SLEEP_SMP depends on PM_SLEEP, so with PM_SLEEP=n it should never be set. That said, regardless of any such problems, I do think that we should think about splitting up HOTPLUG_CPU into two config options: one that allows CPU's to be put to sleep (which is common, and needed for any suspend/hibernate support), and one that actually has support for actual physical hotplugging. Linus