From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934170AbXLMWdd (ORCPT ); Thu, 13 Dec 2007 17:33:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932702AbXLMWct (ORCPT ); Thu, 13 Dec 2007 17:32:49 -0500 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:50638 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S932421AbXLMWcs (ORCPT ); Thu, 13 Dec 2007 17:32:48 -0500 Date: Thu, 13 Dec 2007 14:32:46 -0800 (PST) Message-Id: <20071213.143246.175833292.davem@davemloft.net> To: bunk@kernel.org Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org Subject: Re: RFC: remove __read_mostly From: David Miller In-Reply-To: <20071213222044.GH21616@stusta.de> References: <20071213222044.GH21616@stusta.de> X-Mailer: Mew version 5.2 on Emacs 22.1 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Adrian Bunk Date: Thu, 13 Dec 2007 23:20:44 +0100 > My question is: > Is there anywhere in the kernel a case where __read_mostly brings a > measurable improvement or can it be removed? Yes, on SMP when read-mostly objects share cache lines with other objects which are frequently written to. That is the whole reason we created __read_mostly