From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965030AbVHZOBm (ORCPT ); Fri, 26 Aug 2005 10:01:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965053AbVHZOBm (ORCPT ); Fri, 26 Aug 2005 10:01:42 -0400 Received: from dgate2.fujitsu-siemens.com ([217.115.66.36]:12632 "EHLO dgate2.fujitsu-siemens.com") by vger.kernel.org with ESMTP id S965030AbVHZOBm (ORCPT ); Fri, 26 Aug 2005 10:01:42 -0400 X-SBRSScore: None Message-ID: <430F20BF.1080703@fujitsu-siemens.com> Date: Fri, 26 Aug 2005 16:01:35 +0200 From: Martin Wilck Organization: Fujitsu Siemens Computers User-Agent: Mozilla Thunderbird 0.5 (X11/20040208) X-Accept-Language: de, en-us, en MIME-Version: 1.0 To: "Maciej W. Rozycki" Cc: yhlu , linux-kernel@vger.kernel.org Subject: Re: APIC version and 8-bit APIC IDs References: <42FC8461.2040102@fujitsu-siemens.com.suse.lists.linux.kernel> <42FCA23C.7040601@fujitsu-siemens.com> <20050812133248.GN8974@wotan.suse.de> <42FCA97E.5010907@fujitsu-siemens.com> <42FCB86C.5040509@fujitsu-siemens.com> <20050812145725.GD922@wotan.suse.de> <86802c44050812093774bf4816@mail.gmail.com> <20050812164244.GC22901@wotan.suse.de> <86802c4405081210442b1bb840@mail.gmail.com> <43099FDF.6030504@fujitsu-siemens.com> In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Maciej W. Rozycki wrote: > Well, Intel's "Multiprocessor Specification" mandates that (see section > 3.6.1 and also the compliance list in Appendix C). I does not mandate > local APIC IDs to be consecutive though. Unless I am mistaken, the MP spec does not say that _CPUs_ must start from 0. We had an IO-APIC at 0. The MP spec says that the IDs must be unique (I am told this isn't true any more because an IO APIC and a CPU may have the same ID) and _need not_ be consecutive. We tried different setups; one had IO APICs at 0,1,2 and CPUs starting at 16. I can't see that this is forbidden (the reason is that the IO-APICs have only 4-bit APIC ID registers). Anyway we changed it now to have both IO-APICs and CPUs start at 0. Regards Martin -- Martin Wilck Phone: +49 5251 8 15113 Fujitsu Siemens Computers Fax: +49 5251 8 20409 Heinz-Nixdorf-Ring 1 mailto:Martin.Wilck@Fujitsu-Siemens.com D-33106 Paderborn http://www.fujitsu-siemens.com/primergy