From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755757Ab2FESHq (ORCPT ); Tue, 5 Jun 2012 14:07:46 -0400 Received: from casper.infradead.org ([85.118.1.10]:50232 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753513Ab2FESHo convert rfc822-to-8bit (ORCPT ); Tue, 5 Jun 2012 14:07:44 -0400 Message-ID: <1338919647.2749.30.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 20:07:27 +0200 In-Reply-To: <3908561D78D1C84285E8C5FCA982C28F19300965@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> 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 On Tue, 2012-06-05 at 17:44 +0000, Luck, Tony wrote: > The scheduler may assign a process to run on it, which will wake it up > to use power. But given that you care about how fast a cpu can come up again, this seems to be exactly what you want. You want to adapt to load fast, so why bother going through userspace and wrecking bits in between?