From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: Re: [PATCH 01/14] Introduce cpu_enabled_map and friends Date: Tue, 15 Jul 2008 12:16:32 -0600 Message-ID: <20080715181632.GG14894@parisc-linux.org> References: <20080715023344.2528.1836.stgit@blender.achiang> <20080715023349.2528.9423.stgit@blender.achiang> <20080715031512.GF14894@parisc-linux.org> <87wsjnxy4w.fsf@basil.nowhere.org> <20080715102130.GA22866@flint.arm.linux.org.uk> <20080715175740.GB10919@ldl.fc.hp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20080715175740.GB10919@ldl.fc.hp.com> Sender: linux-acpi-owner@vger.kernel.org To: Alex Chiang , Andi Kleen , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-acpi@vger.kernel.org List-Id: linux-arch.vger.kernel.org On Tue, Jul 15, 2008 at 11:57:40AM -0600, Alex Chiang wrote: > My thought was that big SMP systems like ia64, possibly sparc and > ppc, and increasingly, x86, might find something like this > useful, as systems get larger and larger, and vendors are going > to want to do RAS-ish features, like the ability to keep CPUs in > firmware across reboots until told otherwise by the sysadmin. > > Right now, a 'present' CPU strongly implies 'online' as well, > since we're calling cpu_up() for all 'present' CPUs in > smp_init(). But this hurts if: > > - you don't actually want to bring up all 'present' CPUs > - you still want to interact with these weirdo zombie > CPUs that are 'present' but not 'online' Have you considered simply failing __cpu_up() for CPUs that are deconfigured by firmware? -- Intel are signing my paycheques ... these opinions are still mine "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step." From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from palinux.external.hp.com ([192.25.206.14]:47925 "EHLO mail.parisc-linux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754138AbYGOSQs (ORCPT ); Tue, 15 Jul 2008 14:16:48 -0400 Date: Tue, 15 Jul 2008 12:16:32 -0600 From: Matthew Wilcox Subject: Re: [PATCH 01/14] Introduce cpu_enabled_map and friends Message-ID: <20080715181632.GG14894@parisc-linux.org> References: <20080715023344.2528.1836.stgit@blender.achiang> <20080715023349.2528.9423.stgit@blender.achiang> <20080715031512.GF14894@parisc-linux.org> <87wsjnxy4w.fsf@basil.nowhere.org> <20080715102130.GA22866@flint.arm.linux.org.uk> <20080715175740.GB10919@ldl.fc.hp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080715175740.GB10919@ldl.fc.hp.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Alex Chiang , Andi Kleen , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-acpi@vger.kernel.org Message-ID: <20080715181632.Q4UbVVRi5he8k5EWyGR1d9kT_U1dR1P3wIgcEwxiVCU@z> On Tue, Jul 15, 2008 at 11:57:40AM -0600, Alex Chiang wrote: > My thought was that big SMP systems like ia64, possibly sparc and > ppc, and increasingly, x86, might find something like this > useful, as systems get larger and larger, and vendors are going > to want to do RAS-ish features, like the ability to keep CPUs in > firmware across reboots until told otherwise by the sysadmin. > > Right now, a 'present' CPU strongly implies 'online' as well, > since we're calling cpu_up() for all 'present' CPUs in > smp_init(). But this hurts if: > > - you don't actually want to bring up all 'present' CPUs > - you still want to interact with these weirdo zombie > CPUs that are 'present' but not 'online' Have you considered simply failing __cpu_up() for CPUs that are deconfigured by firmware? -- Intel are signing my paycheques ... these opinions are still mine "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step."