Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758040AbZKDToW (ORCPT ); Wed, 4 Nov 2009 14:44:22 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758030AbZKDToV (ORCPT ); Wed, 4 Nov 2009 14:44:21 -0500 Received: from e5.ny.us.ibm.com ([32.97.182.145]:53549 "EHLO e5.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758031AbZKDToT (ORCPT ); Wed, 4 Nov 2009 14:44:19 -0500 Date: Wed, 4 Nov 2009 11:44:20 -0800 From: "Paul E. McKenney" To: Christoph Lameter Cc: Ingo Molnar , Ian Campbell , Tejun Heo , Linus Torvalds , Andrew Morton , Rusty Russell , linux-kernel Subject: Re: [PATCH] Correct nr_processes() when CPUs have been unplugged Message-ID: <20091104194420.GG6736@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <1257243074.23110.779.camel@zakaz.uk.xensource.com> <20091103160734.GA21362@elte.hu> <20091104060933.GB6830@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.15+20070412 (2007-04-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1082 Lines: 23 On Wed, Nov 04, 2009 at 02:37:06PM -0500, Christoph Lameter wrote: > On Tue, 3 Nov 2009, Paul E. McKenney wrote: > > > > Cpu hotplug is rarely used (what you listed are rare and unusual cases) > > > and therefore online cpus == possible cpus == present cpus. > > > > Though it is not unusual for "possible cpus" to be quite a bit larger > > than "online cpus"... > > The only reason for possible cpus to be larger than online cpus is if you > can actually plugin more processors while the system is running. Typically > the larger possible cpus seems to be some sort of Vendor BIOS screwup > where the vendor advertises how many processors the maximum configuration > of a certain type of hardware would suppport if one would buy that config. Or if you are running as a guest OS on top of some sort of hypervisor. Thanx, Paul -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/