Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758288AbXE2MEI (ORCPT ); Tue, 29 May 2007 08:04:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751252AbXE2MD5 (ORCPT ); Tue, 29 May 2007 08:03:57 -0400 Received: from an-out-0708.google.com ([209.85.132.250]:25571 "EHLO an-out-0708.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750976AbXE2MD4 (ORCPT ); Tue, 29 May 2007 08:03:56 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=D74IGbccuOUxria+WgbpKWwjqzcha7e5mrmlc2j7SxAxbqPmiHgDaQFxZWB0Zl9TdO9N25TIKnZXu7zXLNj1+mi2G6Ld5mxR8uhs7dlkHiRL02nptRIobIs98/+vHY+B7ygKzwZDnIFC2KXK7Sld6P0AVj2Pa55CVCdPsIhwG9I= Message-ID: <4cefeab80705290503k70572e9bmc76e466c7967871b@mail.gmail.com> Date: Tue, 29 May 2007 17:33:55 +0530 From: "Nitin Gupta" To: "Adrian Bunk" Subject: Re: [RFC] LZO de/compression support - take 6 Cc: "Michael-Luke Jones" , "Daniel Hazelton" , lkml , linux-mm-cc@laptop.org, linuxcompressed-devel@lists.sourceforge.net, "Andrew Morton" , "Richard Purdie" , "Bret Towe" In-Reply-To: <20070529114043.GR3899@stusta.de> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <4cefeab80705280734i37df1742k6738cd4200813684@mail.gmail.com> <4cefeab80705280740l36c00bf8t4a6f5b426a7a380a@mail.gmail.com> <200705281049.48679.dhazelton@enter.net> <4cefeab80705280806m39fbcfd6v93a1c847c25e381c@mail.gmail.com> <20070528171115.GQ3899@stusta.de> <7A4314A3-24D8-49E2-BEEF-D760595255A2@cam.ac.uk> <20070529114043.GR3899@stusta.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1650 Lines: 42 On 5/29/07, Adrian Bunk wrote: > On Tue, May 29, 2007 at 09:08:27AM +0100, Michael-Luke Jones wrote: > > On 28 May 2007, at 18:11, Adrian Bunk wrote: > > > >> I have not seen any explanations: > >> - Why did the upstream author write the code that way? > > > > Apparently due to his requirement for extreme portability. The original > > code was designed to work on everything from 16-bit DOS through CRAY > > supercomputers through Windows, Unices and Linux. > > Sure, this could be the reason in some or all cases. > > The upstream author knows the code best, and discussing such issues with > him will in many cases be a win: > > It could be that there was in some cases no good reason, and the > upstream code that gets used by many other projects could become faster. > > Or there was a good reason that applies also to the in-kernel version > and a change breaks some corner case. > I have mailed the author with detailed changelog - waiting for reply. > > The author has stated on the thread that it's a good idea to remove > > unnecessary ifdefs when porting the code into the kernel, given that the > > portability requirements are obviously no longer needed. > > "remove unnecessary ifdefs" implies "generated code is identical". > > That's quite different from "code is 10% faster". > Daniel made some changes to his testing code and now the perf gain is just 1.6%. - Nitin - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/