From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: 2.6.16rc5 'found' an extra CPU. Date: Thu, 2 Mar 2006 20:33:04 +0100 Message-ID: <200603022033.05173.ak@suse.de> References: Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from mail.suse.de ([195.135.220.2]:9900 "EHLO mx1.suse.de") by vger.kernel.org with ESMTP id S1751676AbWCBTdN (ORCPT ); Thu, 2 Mar 2006 14:33:13 -0500 In-Reply-To: Content-Disposition: inline Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: "Brown, Len" Cc: Dave Jones , Chuck Ebbert <76306.1226@compuserve.com>, linux-kernel , linux-acpi On Thursday 02 March 2006 20:26, Brown, Len wrote: > Dave, > Your DSDT looks fine. > I was wrong assuming there were 3 Processor entries there. > > > > Did you really build a 256-CPU SMP kernel or is ACPI > > > ignoring CONFIG_NR_CPUS or something? > > > >Yes, it's =256. > > I expect this is the root problem. It's useless anyways because the x86 apics cannot handle more than 255. Best fix is probably just the appended one. Does that fix the issue? i386 already had it correct BTW. -Andi Limit max number of CPUs to 255 Because 256 causes overflows in some code that stores them in 8 bit fields and the x86 APIC architecture cannot handle more than 255 anyways. Signed-off-by: Andi Kleen Index: linux/arch/x86_64/Kconfig =================================================================== --- linux.orig/arch/x86_64/Kconfig +++ linux/arch/x86_64/Kconfig @@ -323,7 +323,7 @@ config HAVE_ARCH_EARLY_PFN_TO_NID config NR_CPUS int "Maximum number of CPUs (2-256)" - range 2 256 + range 2 255 depends on SMP default "8" help