Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752335Ab2FET4f (ORCPT ); Tue, 5 Jun 2012 15:56:35 -0400 Received: from casper.infradead.org ([85.118.1.10]:51615 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752262Ab2FET43 convert rfc822-to-8bit (ORCPT ); Tue, 5 Jun 2012 15:56:29 -0400 Message-ID: <1338926175.2749.41.camel@twins> Subject: RE: [PATCH 0/6] x86/cpu hotplug: Wake up offline CPU via mwait or nmi From: Peter Zijlstra To: "Luck, Tony" Cc: "Yu, Fenghua" , Rusty Russell , Thomas Gleixner , Ingo Molnar , H Peter Anvin , "Siddha, Suresh B" , "Mallick, Asit K" , Arjan Dan De Ven , linux-kernel , x86 , linux-pm , "Srivatsa S. Bhat" Date: Tue, 05 Jun 2012 21:56:15 +0200 In-Reply-To: <3908561D78D1C84285E8C5FCA982C28F19301A16@ORSMSX104.amr.corp.intel.com> References: <1338833876-29721-1-git-send-email-fenghua.yu@intel.com> <1338842001.28282.135.camel@twins> <87zk8iioam.fsf@rustcorp.com.au> <1338881971.28282.150.camel@twins> <3E5A0FA7E9CA944F9D5414FEC6C7122007727023@ORSMSX105.amr.corp.intel.com> <1338912565.2749.9.camel@twins> <3E5A0FA7E9CA944F9D5414FEC6C7122007728081@ORSMSX105.amr.corp.intel.com> <1338913190.2749.10.camel@twins> <3908561D78D1C84285E8C5FCA982C28F19300965@ORSMSX104.amr.corp.intel.com> <1338919647.2749.30.camel@twins> <3908561D78D1C84285E8C5FCA982C28F19301A16@ORSMSX104.amr.corp.intel.com> Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-Mailer: Evolution 3.2.2- Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 987 Lines: 21 On Tue, 2012-06-05 at 19:54 +0000, Luck, Tony wrote: > My need is for RAS reasons to take a cpu offline - and since > it is broken, I'm not going to bring it back again (at least not anytime > soon - perhaps a service engineer will drive by in a few hours, pull out > the broken cpu, put in a new one, and then bring that online ... but > saving a few milli-seconds in this use case it pointless). Right, performance is completely irrelevant in this case. In fact, the current code should work perfectly fine for you -- except for the whole BSP nightmare x86 has. > Other people want to do this for power saving. They probably do care > how fast the processor can be brought back. They're bloody insane, or working with broken hardware. -- 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/