From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933125AbXGVMxK (ORCPT ); Sun, 22 Jul 2007 08:53:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761593AbXGVMwe (ORCPT ); Sun, 22 Jul 2007 08:52:34 -0400 Received: from ns2.suse.de ([195.135.220.15]:41358 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932694AbXGVMwc (ORCPT ); Sun, 22 Jul 2007 08:52:32 -0400 From: Andi Kleen Organization: SUSE Linux Products GmbH, Nuernberg, GF: Markus Rex, HRB 16746 (AG Nuernberg) To: "Yinghai Lu" Subject: Re: [PATCH 3/3] x86_64: offset apicid_to_node before use it before init_cpu_to_node Date: Sun, 22 Jul 2007 14:52:26 +0200 User-Agent: KMail/1.9.6 Cc: "Andrew Morton" , linux-kernel@vger.kernel.org, joachim.deguara@amd.com References: <86802c440707211749x3258891fhbb72a155dc484e86@mail.gmail.com> In-Reply-To: <86802c440707211749x3258891fhbb72a155dc484e86@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200707221452.27002.ak@suse.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sunday 22 July 2007 02:49:41 Yinghai Lu wrote: > [PATCH 3/3] x86_64: offset apicid_to_node before use it before init_cpu_to_node > > When acpi=off or there is no SRAT defined, apicid_to_node is got from K8 > Northbridge PCI configuration space in k8_scan_nodes() in > arch/x86_64/mm/k8toplogy.c. > The problem is that it assumes bsp apic id is 0 at that point. > For four socket system with Quad core cpus installed, all cpus apic id > is offset by 4, and bsp apic id is 4. > For eight socket system with dual core cpus installed, all cpus apic id > is offset by 2, and bsp apic id is 2. > We need offset apicid_to_node array according to boot_cpu_id.--- bsp apic id. > before we use apicid_to_node array. > boot_cpu_id is only valid init_apic_mappings. This thing is getting more and more messy. If it gets any more complicated I promise I'll rip out the non ACPI support for quad core NUMA completely and let it require ACPI. Even the people who have a religious problem with ACPI will need to eventually get over it and LinuxBIOS just has to create proper tables, not pile hacks over hacks. It probably was a mistake in the first place to add it. I don't think you can mess with apicid_to_node[] unconditionally here. e.g. for the ACPI case or for the Intel NUMA case you'll just break everything. What you should do is split init_apic_mappings() up and do a early call that just checks if the CPU has an APIC and maps it using the fixmap and reads boot_cpu_id. Then you can use that information in k8topology.c to create correct tables. -Andi