From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752010Ab0KZQ0p (ORCPT ); Fri, 26 Nov 2010 11:26:45 -0500 Received: from hera.kernel.org ([140.211.167.34]:51898 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752204Ab0KZQ0n (ORCPT ); Fri, 26 Nov 2010 11:26:43 -0500 Message-ID: <4CEFDF89.3000500@kernel.org> Date: Fri, 26 Nov 2010 17:25:45 +0100 From: Tejun Heo User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); en-US; rv:1.9.2.12) Gecko/20101027 Lightning/1.0b2 Thunderbird/3.1.6 MIME-Version: 1.0 To: Christoph Lameter CC: akpm@linux-foundation.org, Pekka Enberg , linux-kernel@vger.kernel.org, Eric Dumazet , Mathieu Desnoyers , Namhyung Kim Subject: Re: [thiscpuops upgrade 02/10] vmstat: Optimize zone counter modifications through the use of this cpu operations References: <20101123235139.908255844@linux.com> <20101123235157.062638491@linux.com> In-Reply-To: <20101123235157.062638491@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]); Fri, 26 Nov 2010 16:25:47 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/24/2010 12:51 AM, Christoph Lameter wrote: > this cpu operations can be used to slightly optimize the function. The > changes will avoid some address calculations and replace them with the > use of the percpu segment register. > > If one would have this_cpu_inc_return and this_cpu_dec_return then it > would be possible to optimize inc_zone_page_state and dec_zone_page_state even > more. > > Signed-off-by: Christoph Lameter Looks correct to me but it would be nice to run this through sparse. Thanks. -- tejun