Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965200AbWBHEk6 (ORCPT ); Tue, 7 Feb 2006 23:40:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965202AbWBHEk6 (ORCPT ); Tue, 7 Feb 2006 23:40:58 -0500 Received: from mtagate1.de.ibm.com ([195.212.29.150]:20314 "EHLO mtagate1.de.ibm.com") by vger.kernel.org with ESMTP id S965200AbWBHEk5 (ORCPT ); Tue, 7 Feb 2006 23:40:57 -0500 Date: Wed, 8 Feb 2006 05:40:41 +0100 From: Heiko Carstens To: Linus Torvalds Cc: Dipankar Sarma , Richard Henderson , Ivan Kokshaysky , Andrew Morton , dada1@cosmosbay.com, Linux Kernel Mailing List , "David S. Miller" , James.Bottomley@steeleye.com, Ingo Molnar , axboe@suse.de, anton@samba.org, wli@holomorphy.com, ak@muc.de Subject: Re: [PATCH] percpu data: only iterate over possible CPUs Message-ID: <20060208044041.GA9357@osiris.boeblingen.de.ibm.com> References: <200602051959.k15JxoHK001630@hera.kernel.org> <20060207151541.GA32139@osiris.boeblingen.de.ibm.com> <43E8CA10.5070501@cosmosbay.com> <20060207093458.176ac271.akpm@osdl.org> <20060207183018.GA29056@in.ibm.com> <20060207185355.GC5771@in.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: mutt-ng/devel (Linux) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1197 Lines: 29 > > I am looking at 2.6.16-rc1 and I don't see cpu_possible_map > > being set in setup_smp() > > You're right, my bad. I looked at setup_smp() and how it walked through > every CPU in the firmware, but it doesn't actually ever set the possible > map, it fills in just hwrpb_cpu_present_mask (which is then then only used > _later_ to set cpu_possible_map for some silly reason). > > As far as I can tell, "hwrpb_cpu_present_mask" is just wrong, and the code > _should_ be using cpu_possible_map. We still have this one in init/main.c: /* Sets up cpus_possible() */ smp_prepare_cpus(max_cpus); That is actually why s390 is doing this in smp_prepare_cpus. We also use the passed value of max_cpus to set the number of bits in cpu_possible_map accordingly. This isn't possible anymore if this should be done in setup_arch. So it looks like we have to switch to setup_arch and set NR_CPUS bits in cpu_possible_map on s390. Heiko - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/