Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756908AbXKZWBl (ORCPT ); Mon, 26 Nov 2007 17:01:41 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755505AbXKZWBd (ORCPT ); Mon, 26 Nov 2007 17:01:33 -0500 Received: from sca-es-mail-2.Sun.COM ([192.18.43.133]:37297 "EHLO sca-es-mail-2.sun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755052AbXKZWBc (ORCPT ); Mon, 26 Nov 2007 17:01:32 -0500 Date: Mon, 26 Nov 2007 14:06:43 -0800 From: Yinghai Lu Subject: Re: [PATCH] x86_64: not set boot cpu in cpu_online_map at smp_prepare_boot_cpu In-reply-to: <1196110666.6352.309.camel@bodhitayantram.eng.vmware.com> To: Zachary Amsden Cc: Andrew Morton , Thomas Gleixner , LKML Reply-to: Yinghai.Lu@Sun.COM Message-id: <474B4373.9060802@sun.com> MIME-version: 1.0 Content-type: text/plain; format=flowed; charset=ISO-8859-1 Content-transfer-encoding: 7BIT References: <200711260038.41710.yinghai.lu@sun.com> <1196110666.6352.309.camel@bodhitayantram.eng.vmware.com> User-Agent: Thunderbird 2.0.0.9 (X11/20071031) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1298 Lines: 37 Zachary Amsden wrote: > On Mon, 2007-11-26 at 00:38 -0800, Yinghai Lu wrote: >> [PATCH] x86_64: not set boot cpu in cpu_online_map at smp_prepare_boot_cpu >> >> in init/main.c boot_cpu_init() does that before >> >> Signed-off-by: Yinghai Lu >> >> 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? YH - 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/