From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751087AbWAYKY6 (ORCPT ); Wed, 25 Jan 2006 05:24:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751102AbWAYKY6 (ORCPT ); Wed, 25 Jan 2006 05:24:58 -0500 Received: from ebiederm.dsl.xmission.com ([166.70.28.69]:26276 "EHLO ebiederm.dsl.xmission.com") by vger.kernel.org with ESMTP id S1751087AbWAYKY5 (ORCPT ); Wed, 25 Jan 2006 05:24:57 -0500 To: Andrew Morton Cc: Fernando Luis Vazquez Cao , ak@suse.de, vgoyal@in.ibm.com, linux-kernel@vger.kernel.org, fastboot@lists.osdl.org Subject: Re: [PATCH 1/5] stack overflow safe kdump (2.6.16-rc1-i386) - safe_smp_processor_id References: <1138171868.2370.62.camel@localhost.localdomain> <20060124231052.7c9fcbec.akpm@osdl.org> From: ebiederm@xmission.com (Eric W. Biederman) Date: Wed, 25 Jan 2006 03:23:40 -0700 In-Reply-To: <20060124231052.7c9fcbec.akpm@osdl.org> (Andrew Morton's message of "Tue, 24 Jan 2006 23:10:52 -0800") Message-ID: User-Agent: Gnus/5.1007 (Gnus v5.10.7) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andrew Morton writes: > It assumes that all x86 SMP machines have APICs. That's untrue of Voyager. > I think we can probably live with this assumption - others would know > better than I. So looking at the code hard_smp_processor_id is fine. Voyager also implements that. If we are running UP with an SMP kernel we are fine. But I think x86_cpu_to_apicid will get us into trouble on Voyager, because I don't think we should compile smpboot.c as it has conflicting simples with voyager_smp.c Although reading the makefile I don't see how we can avoid compiling them both in SMP mode. Everything else has a local apic when running SMP so we should be good there. Eric