From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757861Ab1KQQGs (ORCPT ); Thu, 17 Nov 2011 11:06:48 -0500 Received: from terminus.zytor.com ([198.137.202.10]:40161 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754394Ab1KQQGr (ORCPT ); Thu, 17 Nov 2011 11:06:47 -0500 Message-ID: <4EC53105.4050301@zytor.com> Date: Thu, 17 Nov 2011 08:06:29 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:7.0.1) Gecko/20110930 Thunderbird/7.0.1 MIME-Version: 1.0 To: Konrad Rzeszutek Wilk CC: HAYASAKA Mitsuo , Thomas Gleixner , Ingo Molnar , Randy Dunlap , x86@kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, yrl.pp-manager.tt@hitachi.com Subject: Re: [RFC PATCH 3/5] x86: add a sysctl parameter to panic on stack overflow References: <20111107055108.7928.89454.stgit@ltc219.sdl.hitachi.co.jp> <20111107055301.7928.91628.stgit@ltc219.sdl.hitachi.co.jp> <20111110195538.GB22646@phenom.dumpdata.com> <4EC4B38B.2010301@hitachi.com> <20111117160021.GC6008@phenom.dumpdata.com> In-Reply-To: <20111117160021.GC6008@phenom.dumpdata.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/17/2011 08:00 AM, Konrad Rzeszutek Wilk wrote: >> >> I don't mind if I add __read_mostly here, but I think it's not >> necessary because this variable is seldom read as well. > > The definition of __read_mostly is that it moves this variable to a cold cache area. > Which is what you want. > Not really. __read_mostly moves a variable to an area that is expected to spent most its time in the cache-shared state and rarely be invalidated. It does NOT mean that it is cold. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.