Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754301Ab0BRBdk (ORCPT ); Wed, 17 Feb 2010 20:33:40 -0500 Received: from terminus.zytor.com ([198.137.202.10]:41848 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751385Ab0BRBdj (ORCPT ); Wed, 17 Feb 2010 20:33:39 -0500 Message-ID: <4B7C98B9.1090903@zytor.com> Date: Wed, 17 Feb 2010 17:32:41 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.7) Gecko/20100120 Fedora/3.0.1-1.fc12 Thunderbird/3.0.1 MIME-Version: 1.0 To: Yinghai Lu CC: Ingo Molnar , Thomas Gleixner , Andrew Morton , Linus Torvalds , Jesse Barnes , Christoph Lameter , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org Subject: Re: [PATCH 34/35] x86: use num_processors for possible cpus References: <1265793639-15071-1-git-send-email-yinghai@kernel.org> <1265793639-15071-35-git-send-email-yinghai@kernel.org> In-Reply-To: <1265793639-15071-35-git-send-email-yinghai@kernel.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1169 Lines: 30 On 02/10/2010 01:20 AM, Yinghai Lu wrote: > some systems that have disable cpus entries because same > BIOS will support 2 sockets and 4 sockets and more at > same time, BIOS just leave some disable entries, but > those system do not support cpu hotplug. we don't need > treat disabled_cpus as hotplug cpus. > so we can make nr_cpu_ids smaller and save more space > (pcpu data allocations), and could make some systems run > with logical flat instead of physical flat apic mode > > -v2: change to black list instead > -v3: just remove that, and the one use possible_cpus= directly. > > Signed-off-by: Yinghai Lu I'm confused by this one. This would seem to mean that unless you're specifying possible_cpus= then you are not treating anything as hotpluggable. This is clearly wrong, and it would appear to go the wrong direction in terms of what is safe. What am I missing here? -hpa -- 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/