Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756206Ab2JVUjY (ORCPT ); Mon, 22 Oct 2012 16:39:24 -0400 Received: from terminus.zytor.com ([198.137.202.10]:36070 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754195Ab2JVUjX (ORCPT ); Mon, 22 Oct 2012 16:39:23 -0400 Message-ID: <5085AEDE.1060806@zytor.com> Date: Mon, 22 Oct 2012 13:38:54 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:13.0) Gecko/20120605 Thunderbird/13.0 MIME-Version: 1.0 To: "Eric W. Biederman" CC: HATAYAMA Daisuke , linux-kernel@vger.kernel.org, kexec@lists.infradead.org, x86@kernel.org, mingo@elte.hu, tglx@linutronix.de, len.brown@intel.com, fenghua.yu@intel.com, vgoyal@redhat.com, grant.likely@secretlab.ca, rob.herring@calxeda.com Subject: Re: [PATCH v1 2/2] x86, apic: Disable BSP if boot cpu is AP References: <20121016043357.20003.5885.stgit@localhost6.localdomain6> <20121016043528.20003.601.stgit@localhost6.localdomain6> <873916i88t.fsf@xmission.com> <5085A9A8.5020004@zytor.com> <87fw56fduo.fsf@xmission.com> <5085AD7D.106@zytor.com> In-Reply-To: <5085AD7D.106@zytor.com> X-Enigmail-Version: 1.4.3 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1198 Lines: 34 On 10/22/2012 01:33 PM, H. Peter Anvin wrote: > On 10/22/2012 01:31 PM, Eric W. Biederman wrote: >>> >>> IIRC Fenghua experimented with that and it didn't work. Not all BIOSes >>> use that bit to determine BSP-ness. >> >> What does a BIOS have to do with anything? >> >> The practical issue here is does an INIT IPI cause the cpu to go into >> startup-ipi-wait or to start booting at 4G-16 bytes. >> >> For dealing with BIOSen we may still need to use the bootstrap processor >> for firmware calls, cpu suspend, and other firmware weirdness, but that >> should all be completely orthogonal to the behavior to what happens >> when an INIT IPI is sent to the cpu. >> >> The only firmware problem I can imagine having is cpu virtualization >> bug. >> > > The whole problem is that some BIOSes go wonky after receiving an INIT > (as in INIT-SIPI-SIPI) to the BSP. > (I presume the failure is SMM-related, but Fenghua might have more details...) -hpa -- 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/