Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758609AbYHNJLq (ORCPT ); Thu, 14 Aug 2008 05:11:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753793AbYHNJLi (ORCPT ); Thu, 14 Aug 2008 05:11:38 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:37852 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752450AbYHNJLi (ORCPT ); Thu, 14 Aug 2008 05:11:38 -0400 Date: Thu, 14 Aug 2008 11:11:20 +0200 From: Ingo Molnar To: Max Krasnyansky Cc: linux-kernel@vger.kernel.org, Max Krasnyansky , lizf@cn.fujitsu.com, jeff.chua.linux@gmail.com, "H. Peter Anvin" , Thomas Gleixner Subject: Re: [PATCH] Resurect proper handling of maxcpus= kernel option (take 2) Message-ID: <20080814091120.GA18771@elte.hu> References: <1218491731-10673-1-git-send-email-maxk@qualcomm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1218491731-10673-1-git-send-email-maxk@qualcomm.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1381 Lines: 32 * Max Krasnyansky wrote: > From: Max Krasnyansky > > For some reason we had two parsers registered for maxcpus=. One in init/main.c > and another in arch/x86/smpboot.c. So I nuked the one in arch/x86. > > Also 64-bit kernels used to handle maxcpus= as documented in > Documentation/cpu-hotplug.txt. CPUs with 'id > maxcpus' are initialized > but not booted. 32-bit version for some reason ignored them even though > all the infrastructure for booting them later is there. > > In the current mainline both 64 and 32 bit versions are broken. > This patch restores the correct behaviour. I've tested x86_64 version on > 4- and 8- way Core2 and 2-way Opteron based machines. Various config > combinations SMP, !SMP, CPU_HOTPLUG, !CPU_HOTPLUG. > Booted with maxcpus=1 and maxcpus=4, etc. Everything is working as expected. > > So far we've received two reports from different people confirming that 32-bit > version also works fine, both on dual core laptops and 16way server machines. > > This version fixes visws breakage pointed out by Ingo. applied to tip/x86/urgent, thanks Max. Ingo -- 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/