Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754168Ab2FEQTI (ORCPT ); Tue, 5 Jun 2012 12:19:08 -0400 Received: from mga14.intel.com ([143.182.124.37]:8764 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753941Ab2FEQTG convert rfc822-to-8bit (ORCPT ); Tue, 5 Jun 2012 12:19:06 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.71,315,1320652800"; d="scan'208";a="108114659" From: "Yu, Fenghua" To: Peter Zijlstra CC: Rusty Russell , Thomas Gleixner , Ingo Molnar , H Peter Anvin , "Siddha, Suresh B" , "Luck, Tony" , "Mallick, Asit K" , Arjan Dan De Ven , linux-kernel , x86 , linux-pm , "Srivatsa S. Bhat" Subject: RE: [PATCH 0/6] x86/cpu hotplug: Wake up offline CPU via mwait or nmi Thread-Topic: [PATCH 0/6] x86/cpu hotplug: Wake up offline CPU via mwait or nmi Thread-Index: AQHNQoAPrrSeWa27GkKpGKrFiBcRb5brDNOAgAAGFYCAAEURgIAAdQ+AgAAVOjCAAHk9gP//iyfg Date: Tue, 5 Jun 2012 16:18:35 +0000 Message-ID: <3E5A0FA7E9CA944F9D5414FEC6C7122007728081@ORSMSX105.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> In-Reply-To: <1338912565.2749.9.camel@twins> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.22.254.140] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1298 Lines: 30 > From: Peter Zijlstra [mailto:peterz@infradead.org] > Sent: Tuesday, June 05, 2012 9:09 AM > To: Yu, Fenghua > Cc: Rusty Russell; Thomas Gleixner; Ingo Molnar; H Peter Anvin; Siddha, > Suresh B; Luck, Tony; Mallick, Asit K; Arjan Dan De Ven; linux-kernel; > x86; linux-pm; Srivatsa S. Bhat > Subject: RE: [PATCH 0/6] x86/cpu hotplug: Wake up offline CPU via mwait > or nmi > > On Tue, 2012-06-05 at 16:02 +0000, Yu, Fenghua wrote: > > > > Users can consolidate processes on a few online CPU's and offline the > > rest when workload is light. > > No they can't, hotplug is a root only op. That's right. A root admin does this. Actually some Linux people are adjusting online/offline CPU's based on workload to save power in their business. There are some advantages for online/offline CPU's than idling CPU's. > > > This consolidation can save more power and have better performance > > than idling CPU's because hot cache in online CPU's and offline CPU's > > can be allocated in same package. > > Yeah, or you fix the load-balancer to do this. -- 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/