From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266564AbUHBPvC (ORCPT ); Mon, 2 Aug 2004 11:51:02 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266565AbUHBPvC (ORCPT ); Mon, 2 Aug 2004 11:51:02 -0400 Received: from jade.spiritone.com ([216.99.193.136]:15515 "EHLO jade.spiritone.com") by vger.kernel.org with ESMTP id S266564AbUHBPvA (ORCPT ); Mon, 2 Aug 2004 11:51:00 -0400 Date: Mon, 02 Aug 2004 08:50:53 -0700 From: "Martin J. Bligh" To: Arjan van de Ven , linux-kernel@vger.kernel.org Subject: Re: finding out the boot cpu number from userspace Message-ID: <12690000.1091461852@[10.10.2.4]> In-Reply-To: <20040802121635.GE14477@devserv.devel.redhat.com> References: <20040802121635.GE14477@devserv.devel.redhat.com> X-Mailer: Mulberry/2.2.1 (Linux/x86) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > assuming cpu 0 is the boot cpu sounds fragile/incorrect, but for irqbalanced > I'd like to find out which cpu is the boot cpu, is there a good way of doing > so ? > > The reason for needing this is that some firmware only likes running on the > boot cpu so I need to bind firmware-related irq's to that cpu ideally. On any sane arch, cpu 0 *IS* always the boot CPU, as we dynamically number CPUs that way ... that doesn't mean that it's apicid 0. I believe that PPC64 screwed this up, but AFAIK, everyone else gets it correct ... ;-) M.