From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753470Ab0LOQdU (ORCPT ); Wed, 15 Dec 2010 11:33:20 -0500 Received: from hera.kernel.org ([140.211.167.34]:33878 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751187Ab0LOQdS (ORCPT ); Wed, 15 Dec 2010 11:33:18 -0500 Message-ID: <4D08EDA9.3090801@kernel.org> Date: Wed, 15 Dec 2010 17:32:41 +0100 From: Tejun Heo User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); en-US; rv:1.9.2.13) Gecko/20101207 Lightning/1.0b2 Thunderbird/3.1.7 MIME-Version: 1.0 To: Christoph Lameter CC: akpm@linux-foundation.org, Peter Zijlstra , Pekka Enberg , linux-kernel@vger.kernel.org, Eric Dumazet , "H. Peter Anvin" , Mathieu Desnoyers Subject: Re: [cpuops cmpxchg V2 3/5] irq_work: Use per cpu atomics instead of regular atomics References: <20101214162842.542421046@linux.com> <20101214162854.218751478@linux.com> In-Reply-To: <20101214162854.218751478@linux.com> X-Enigmail-Version: 1.1.1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Wed, 15 Dec 2010 16:32:43 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/14/2010 05:28 PM, Christoph Lameter wrote: > The irq work queue is a per cpu object and it is sufficient for > synchronization if per cpu atomics are used. Doing so simplifies > the code and reduces the overhead of the code. > > Before: > > christoph@linux-2.6$ size kernel/irq_work.o > text data bss dec hex filename > 451 8 1 460 1cc kernel/irq_work.o > > After: > > christoph@linux-2.6$ size kernel/irq_work.o > text data bss dec hex filename > 438 8 1 447 1bf kernel/irq_work.o > > Cc: Peter Zijlstra Peter, can you please ack this one? Thanks. -- tejun