From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1754427Ab1LFND4 (ORCPT <rfc822;w@1wt.eu>);
	Tue, 6 Dec 2011 08:03:56 -0500
Received: from s15228384.onlinehome-server.info ([87.106.30.177]:55448 "EHLO
	mail.x86-64.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1753717Ab1LFNDz (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Tue, 6 Dec 2011 08:03:55 -0500
Date: Tue, 6 Dec 2011 14:03:51 +0100
From: Borislav Petkov <bp@amd64.org>
To: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>, Fenghua Yu <fenghua.yu@intel.com>,
        "Rafael J. Wysocki" <rjw@sisk.pl>,
        Thomas Gleixner <tglx@linutronix.de>, H Peter Anvin <hpa@zytor.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Tony Luck <tony.luck@intel.com>,
        Arjan van de Ven <arjan.van.de.ven@intel.com>,
        Suresh B Siddha <suresh.b.siddha@intel.com>,
        Len Brown <len.brown@intel.com>, Randy Dunlap <rdunlap@xenotime.net>,
        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
        Peter Zijlstra <peterz@infradead.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        linux-pm <linux-pm@vger.kernel.org>, x86 <x86@kernel.org>,
        Tejun Heo <tj@kernel.org>, Borislav Petkov <bp@amd64.org>,
        "Herrmann3, Andreas" <Andreas.Herrmann3@amd.com>
Subject: Re: [PATCH v4 0/7] x86: BSP or CPU0 online/offline
Message-ID: <20111206130351.GC28735@gere.osrc.amd.com>
References: <1321075592-31600-1-git-send-email-fenghua.yu@intel.com>
 <20111206084230.GC30062@elte.hu>
 <20111206085816.GA11116@elte.hu>
 <4EDDE5D0.7030906@linux.vnet.ibm.com>
 <20111206103500.GD15966@elte.hu>
 <4EDDF2DE.7020701@linux.vnet.ibm.com>
 <4EDDFB8E.10801@linux.vnet.ibm.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <4EDDFB8E.10801@linux.vnet.ibm.com>
User-Agent: Mutt/1.5.21 (2010-09-15)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Tue, Dec 06, 2011 at 04:55:02PM +0530, Srivatsa S. Bhat wrote:
> By the way, this problem is not tied to CPU0 alone, it exists for any
> CPU! (as long as we are talking about plugging in/out CPUs physically).

Just a reminder: before you guys go and wander off into the woods of
hypothetical with this, please make sure this use case is relevant
enough for the trouble. The only real reason given so far AFAICT was RAS
and to be able to offline BSP in order to prolong system life before
maintenance.

When you take it down for maintenance eventually, you don't need to
suspend but simply poweroff.

Or...

-- 
Regards/Gruss,
Boris.

Advanced Micro Devices GmbH
Einsteinring 24, 85609 Dornach
GM: Alberto Bozzo
Reg: Dornach, Landkreis Muenchen
HRB Nr. 43632 WEEE Registernr: 129 19551