Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757935Ab3DSIcp (ORCPT ); Fri, 19 Apr 2013 04:32:45 -0400 Received: from e23smtp01.au.ibm.com ([202.81.31.143]:43671 "EHLO e23smtp01.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751844Ab3DSIcm (ORCPT ); Fri, 19 Apr 2013 04:32:42 -0400 Message-ID: <5171006D.40600@linux.vnet.ibm.com> Date: Fri, 19 Apr 2013 13:59:33 +0530 From: "Srivatsa S. Bhat" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:15.0) Gecko/20120828 Thunderbird/15.0 MIME-Version: 1.0 To: Ingo Molnar CC: Borislav Petkov , Robin Holt , Ingo Molnar , Russ Anderson , Shawn Guo , Oleg Nesterov , Andrew Morton , "H. Peter Anvin" , Joe Perches , Lai Jiangshan , Linus Torvalds , Linux Kernel Mailing List , Michel Lespinasse , "Paul E. McKenney" , Paul Mackerras , Peter Zijlstra , "rusty@rustcorp.com.au" , Tejun Heo , the arch/x86 maintainers , Thomas Gleixner , Fenghua Yu Subject: Re: [Patch -v4 1/4] Migrate shutdown/reboot to boot cpu. References: <20130416095827.GJ3672@sgi.com> <20130416113256.GA10452@gmail.com> <20130416120624.GO3658@sgi.com> <20130416140101.GS3658@sgi.com> <20130417074653.GA31607@gmail.com> <20130417092737.GA12402@pd.tnic> <20130419075629.GE20897@gmail.com> In-Reply-To: <20130419075629.GE20897@gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13041908-1618-0000-0000-000003B9CF12 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1859 Lines: 41 On 04/19/2013 01:26 PM, Ingo Molnar wrote: > > * Borislav Petkov wrote: > >> On Wed, Apr 17, 2013 at 09:46:53AM +0200, Ingo Molnar wrote: >> >>> What you mention here should indeed already be handled by the architecture >>> hotplug code (for example on x86 the boot CPU cannot be hot-removed). >> >> Supposedly, some new Intels (I think Ivybridge or so) can actually be >> hot-removed. > > There are WIP patches in existence that remove the limitations on the kernel side, > but they are not upstream yet, so currently the constraint exists upstream. > I thought Fenghua Yu's upstream commits were supposed to handle that. Don't they? a71c8bc x86, topology: Debug CPU0 hotplug 6f5298c x86/i387.c: Initialize thread xstate only on CPU0 only once 8d966a0 x86, hotplug: Handle retrigger irq by the first available CPU 30242aa x86, hotplug: The first online processor saves the MTRR state 27fd185 x86, hotplug: During CPU0 online, enable x2apic, set_numa_node. e1c467e x86, hotplug: Wake up CPU0 via NMI instead of INIT, SIPI, SIPI 3e2a0cc x86-32, hotplug: Add start_cpu0() entry point to head_32.S 42e78e9 x86-64, hotplug: Add start_cpu0() entry point to head_64.S 6e32d47 kernel/cpu.c: Add comment for priority in cpu_hotplug_pm_callback 209efae x86, hotplug, suspend: Online CPU0 for suspend or hibernate 30106c1 x86, hotplug: Support functions for CPU0 online/offline 4d25031 x86, topology: Don't offline CPU0 if any PIC irq can not be migrated out of it 80aa1df x86, Kconfig: Add config switch for CPU0 hotplug f78cff4 doc: Add x86 CPU0 online/offline feature Regards, Srivatsa S. Bhat -- 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/