From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754287Ab3KTQi4 (ORCPT ); Wed, 20 Nov 2013 11:38:56 -0500 Received: from mga02.intel.com ([134.134.136.20]:22714 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754159Ab3KTQix (ORCPT ); Wed, 20 Nov 2013 11:38:53 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.93,535,1378882800"; d="scan'208";a="438620390" Message-ID: <528CE59C.1040600@linux.intel.com> Date: Wed, 20 Nov 2013 08:38:52 -0800 From: Arjan van de Ven User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.1.0 MIME-Version: 1.0 To: Peter Zijlstra CC: Jacob Pan , lenb@kernel.org, rjw@rjwysocki.net, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, shaohua.li@intel.com, rui.zhang@intel.com, Mike Galbraith , Ingo Molnar , Thomas Gleixner , hpa@zytor.com Subject: Re: [PATCH] x86, acpi, idle: Restructure the mwait idle routines References: <20131119090019.GJ3866@twins.programming.kicks-ass.net> <20131119090859.GC3694@twins.programming.kicks-ass.net> <20131119113153.GD3694@twins.programming.kicks-ass.net> <528B7433.7020507@linux.intel.com> <20131119145143.GK10022@twins.programming.kicks-ass.net> <20131119151338.GF3694@twins.programming.kicks-ass.net> <20131119130630.487da962@ultegra> <20131120102803.GO10022@twins.programming.kicks-ass.net> <20131120105837.GH3694@twins.programming.kicks-ass.net> <528CE24F.5000604@linux.intel.com> <20131120163313.GR10022@twins.programming.kicks-ass.net> In-Reply-To: <20131120163313.GR10022@twins.programming.kicks-ass.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/20/2013 8:33 AM, Peter Zijlstra wrote: > On Wed, Nov 20, 2013 at 08:24:47AM -0800, Arjan van de Ven wrote: >> On 11/20/2013 2:58 AM, Peter Zijlstra wrote: >>> So pretty silly actually; you cannot do a store (any store) in between >>> monitor and mwait. >> >> you can >> just not to the cacheline you are watching (or things that alias with that) > > Ah indeed, the thread_info::status is in the same cacheline. > you told it to wake on any write to that cacheline and then you write to it ;-)