Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757004AbXKZWcz (ORCPT ); Mon, 26 Nov 2007 17:32:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755865AbXKZWcs (ORCPT ); Mon, 26 Nov 2007 17:32:48 -0500 Received: from smtp-outbound-1.vmware.com ([65.113.40.141]:43444 "EHLO smtp-outbound-1.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755543AbXKZWcs (ORCPT ); Mon, 26 Nov 2007 17:32:48 -0500 Subject: Re: [PATCH] x86_64: not set boot cpu in cpu_online_map at smp_prepare_boot_cpu From: Zachary Amsden To: Yinghai.Lu@Sun.COM Cc: Andrew Morton , Thomas Gleixner , LKML In-Reply-To: <474B4373.9060802@sun.com> References: <200711260038.41710.yinghai.lu@sun.com> <1196110666.6352.309.camel@bodhitayantram.eng.vmware.com> <474B4373.9060802@sun.com> Content-Type: text/plain Date: Mon, 26 Nov 2007 14:36:24 -0800 Message-Id: <1196116584.6352.314.camel@bodhitayantram.eng.vmware.com> Mime-Version: 1.0 X-Mailer: Evolution 2.10.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1298 Lines: 36 On Mon, 2007-11-26 at 14:06 -0800, Yinghai Lu wrote: > >> diff --git a/arch/x86/kernel/smpboot_64.c b/arch/x86/kernel/smpboot_64.c > >> index 500670c..966d124 100644 > >> --- a/arch/x86/kernel/smpboot_64.c > >> +++ b/arch/x86/kernel/smpboot_64.c > >> @@ -912,7 +912,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus) > >> void __init smp_prepare_boot_cpu(void) > >> { > >> int me = smp_processor_id(); > >> - cpu_set(me, cpu_online_map); > >> + /* already set me in cpu_online_map in boot_cpu_init() */ > >> cpu_set(me, cpu_callout_map); > >> per_cpu(cpu_state, me) = CPU_ONLINE; > >> } > > > > > > This ordering can be tricky wrt CPU hotplug. Are you sure you are not > > breaking CPU hotplug? AFAIK, x86_64 has that right and the 32-bit code > > had it wrong. > > > CPU hot plug path will call smp_prepare_boot_cpu? > it is using __init instead of __cpuinit? No, but moving the place where cpu is moved into online map might break hotplug. In any case, I don't see anything wrong with your change now that I look closer. Zach - 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/