Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760480AbXE1QER (ORCPT ); Mon, 28 May 2007 12:04:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751327AbXE1QEB (ORCPT ); Mon, 28 May 2007 12:04:01 -0400 Received: from an-out-0708.google.com ([209.85.132.241]:65211 "EHLO an-out-0708.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751211AbXE1QEA (ORCPT ); Mon, 28 May 2007 12:04:00 -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=uZVNhOiJTIc1Knn8boFLPVE/h/kPWJ2SZsfkcYKYIZLEe6CUELN4ElWTjrOmN1+/3fG9i7ncN+I0fVkTafevU5wDIL41YTwEIYy4x5ujyjjMJ7s6ApdfRBqfmy18jbaKaSia3D8MXhn0DzKeLYYn9GLBaIU67Zp8GOoCtVidgJk= Message-ID: <4cefeab80705280903t6b2bb687g4eb1d9de2717f6ec@mail.gmail.com> Date: Mon, 28 May 2007 21:33:32 +0530 From: "Nitin Gupta" To: "Adrian Bunk" Subject: Re: [RFC] LZO de/compression support - take 6 Cc: "Daniel Hazelton" , lkml , linux-mm-cc@laptop.org, linuxcompressed-devel@lists.sourceforge.net, "Andrew Morton" , "Richard Purdie" , "Bret Towe" , "Satyam Sharma" In-Reply-To: <20070528154346.GO3899@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> <20070528154346.GO3899@stusta.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1895 Lines: 48 On 5/28/07, Adrian Bunk wrote: > On Mon, May 28, 2007 at 08:36:44PM +0530, Nitin Gupta wrote: > >... > > So, before this change, it will be good if it gets merged in mainline > > and tested, at least for correctness, on all supported achs. All the > > while, we will have a good feeling that there is still a good scope > > for perf improvement :) > > The correct order is: > - create one version with all the optimizations you have in mind Already done. One more optimization is regarding use of memcpy() in place of COPY4() macros and open byte-by-byte copying. There are some places where it's very hard to get it correct without adding additional checks on various values which casues futher overhead by iteslf - even then I could not get them correct so I decided not to go with this particular optimization by myself. > - then ensure that it works correctly on all architectures and Already tested on x86, amd64, ppc (by Bret). I do not have machines from other archs available. Bret tested 'take 3' version but no changes were introduced in further revisions that could affect correctness - but still it will be good to have this version tested too. Only with inclusion in -mm and testing by much wider user base can make it to mainline (I suppose nobody uses -mm for production use anyway). > document why your version is that much faster than the original > version and why you know your optimizations have no side effects Replied in earlier mail regarding this. > - then get it tested in -mm > This is what I am looking for :) > After these steps, you can start considering getting it into mainline. > - 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/