From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964961AbWD0GYi (ORCPT ); Thu, 27 Apr 2006 02:24:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964960AbWD0GYi (ORCPT ); Thu, 27 Apr 2006 02:24:38 -0400 Received: from smtp104.mail.mud.yahoo.com ([209.191.85.214]:60014 "HELO smtp104.mail.mud.yahoo.com") by vger.kernel.org with SMTP id S964961AbWD0GYi (ORCPT ); Thu, 27 Apr 2006 02:24:38 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Received:Message-ID:Date:From:User-Agent:X-Accept-Language:MIME-Version:To:CC:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=tTvk9Y55E9tzBHpUqDqy5VDCwuV2jlbsTgQsHDWFziQc2EPDdlzLQkRvk9/XIb5uKBUQASV9Jm3wqOl4377QBNdyAmOzIoNynjrU72+DTyrrsfoH+YIxCOOp4euRZ8biuDh2hYOae/N6xBmxhyOa73+itsqgUHFwL/+E9waEn+U= ; Message-ID: <445061DC.5030008@yahoo.com.au> Date: Thu, 27 Apr 2006 16:17:00 +1000 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12) Gecko/20051007 Debian/1.7.12-1 X-Accept-Language: en MIME-Version: 1.0 To: Pekka J Enberg CC: =?ISO-8859-1?Q?J=F6rn_Engel?= , Arjan van de Ven , Hua Zhong , linux-kernel@vger.kernel.org, akpm@osdl.org Subject: Re: [PATCH] likely cleanup: remove unlikely for kfree(NULL) References: <84144f020604260030v26f42b0bke639053928d5e471@mail.gmail.com> <1146038324.5956.0.camel@laptopd505.fenrus.org> <1146040038.7016.0.camel@laptopd505.fenrus.org> <20060426100559.GC29108@wohnheim.fh-wedel.de> <1146046118.7016.5.camel@laptopd505.fenrus.org> <1146049414.7016.9.camel@laptopd505.fenrus.org> <20060426110656.GD29108@wohnheim.fh-wedel.de> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Pekka J Enberg wrote: > On Wed, 26 Apr 2006, Jörn Engel wrote: > >>Still, if you could respin this with gcc 4.1 and post the numbers, >>Pekka, that would be quite interesting. > > > Inlining kfree the way I did doesn't pay off in 4.1 either. Not to dispute your conclusions or method, but I think doing a defconfig or your personal config might be more representative of % size increase of text that will actually be executed. And that is the expensive type of text. eg. core code may contain many more instances of checks that cannot be optimised away, meaning it may be a more significant cache footprint increase than the 0.05% increase in your test. Of course, it is equally possible that the instances in core code do not represent often-executed code, so it is a bit of a fudge either way. > text data bss dec hex filename > 24910301 6946478 2092332 33949111 20605b7 vmlinux-gcc-3.4.5 > 24934157 6946530 2092332 33973019 206631b vmlinux-inline-kfree-gcc-3.4.5 > 24171004 6484710 2090188 32745902 1f3a9ae vmlinux-gcc-4.1.0 > 24185925 6484722 2090188 32760835 1f3e403 vmlinux-inline-kfree-gcc-4.1.0 -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com