From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751953Ab0CIHjC (ORCPT ); Tue, 9 Mar 2010 02:39:02 -0500 Received: from hera.kernel.org ([140.211.167.34]:37765 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751027Ab0CIHjA (ORCPT ); Tue, 9 Mar 2010 02:39:00 -0500 Message-ID: <4B95FB06.6070906@kernel.org> Date: Tue, 09 Mar 2010 16:38:46 +0900 From: Tejun Heo User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.5) Gecko/20091130 SUSE/3.0.0-1.1.1 Thunderbird/3.0 MIME-Version: 1.0 To: =?UTF-8?B?QW5kcsOpIEdvZGRhcmQgUm9zYQ==?= CC: Greg Kroah-Hartman , Alex Chiang , Kenji Kaneshige , Serge Hallyn , linux-kernel@vger.kernel.org Subject: Re: [PATCH] sysfs/file: move NULL checks to where they make sense and can occur References: <2fcd155e7b67ba2d41de0a5a0751b3091bf849d8.1267785770.git.andre.goddard@gmail.com> In-Reply-To: <2fcd155e7b67ba2d41de0a5a0751b3091bf849d8.1267785770.git.andre.goddard@gmail.com> X-Enigmail-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Tue, 09 Mar 2010 07:38:48 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On 03/05/2010 07:46 PM, André Goddard Rosa wrote: > ... avoiding checking for NULL 2 times in a row when we already have a page. > > It decreases code size: > text data bss dec hex filename > 4246 48 4136 8430 20ee fs/sysfs/file-BEFORE.o > 4214 48 4136 8398 20ce fs/sysfs/file-AFTER.o > > Signed-off-by: André Goddard Rosa Nacked-by: Tejun Heo For this level of micro optimization to be meaningful, the code path should be *really* *really* hot, which none of sysfs code pats are. Whatever is easier to the eyes wins. Thanks. -- tejun