Return-Path: <linux-kernel-owner+w=401wt.eu-S1763071AbXEYTf4@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1763071AbXEYTf4 (ORCPT <rfc822;w@1wt.eu>);
	Fri, 25 May 2007 15:35:56 -0400
Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753273AbXEYTft
	(ORCPT <rfc822;linux-kernel-outgoing>);
	Fri, 25 May 2007 15:35:49 -0400
Received: from an-out-0708.google.com ([209.85.132.242]:13869 "EHLO
	an-out-0708.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1753031AbXEYTfs (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Fri, 25 May 2007 15:35:48 -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=S1aaiyt+L2gp1hd/mhjZfmxmnbBasmtLKt/cyBg6+Qw90xWYA/a/5Kgc/ilZ8YOTEhYSc5fXxIOmM2FnNYIRTEvaQpNu4T234JLn2LtZUY16QQiwjQJzb7XuzM42BwGjLxCj9MT7A5wKiiXs0+5ZU6kbXhSXGtuipjPo+fXCiw8=
Message-ID: <a781481a0705251235q37084077r86bc166b145a0d8a@mail.gmail.com>
Date: Sat, 26 May 2007 01:05:41 +0530
From: "Satyam Sharma" <satyam.sharma@gmail.com>
To: "Daniel Hazelton" <dhazelton@enter.net>
Subject: Re: [RFC] LZO de/compression support - take 4
Cc: "Richard Purdie" <richard@openedhand.com>,
       "Nitin Gupta" <nitingupta910@gmail.com>, linux-kernel@vger.kernel.org,
       linux-mm-cc@laptop.org, "Andrew Morton" <akpm@linux-foundation.org>,
       "Andrey Panin" <pazke@donpac.ru>, "Bret Towe" <magnade@gmail.com>,
       "Michael-Luke Jones" <mlj28@cam.ac.uk>
In-Reply-To: <200705251445.18188.dhazelton@enter.net>
MIME-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
References: <4cefeab80705250445m51736a9aj8c89af893d8c242c@mail.gmail.com>
	 <1180100304.5864.60.camel@localhost.localdomain>
	 <200705251255.22600.dhazelton@enter.net>
	 <200705251445.18188.dhazelton@enter.net>
Sender: linux-kernel-owner@vger.kernel.org
X-Mailing-List: linux-kernel@vger.kernel.org
Content-Length: 2075
Lines: 42

Hi Daniel,

On 5/26/07, Daniel Hazelton <dhazelton@enter.net> wrote:
> On Friday 25 May 2007 12:55:21 Daniel Hazelton wrote:
> <snip>
> > As to the performance - I can see absolutely no reason why the minimal
> > version shouldn't perform the same (or better). The kernel codes memset and
> > memcpy routines have been heavily tested *and* optimized over the years and
> > moving from macro's to inline functions shouldn't have impacted performance
> > at all. I will be testing the two code bases myself in a little bit - I'm
> > more than a little paranoid and don't like the idea of trusting anyone with
> > a "competing project" for all testing.
>
>
> I'll have to better instrument my test code (a real quick (userspace) hack)
> using the minimized LZO1X implementation (take 4 :) and the complete LZOv2
> library (lzo1x_1_11_compress and the *unsafe* version of the decompressor
> used) but preliminary testing using just "time ./test" - the differences I've
> seen might be because I'm directly including one version of the code and the
> other is in a shared library. But even if I discount the system and user
> time - going *only* by the "real" time value I get results across 10 runs
> that differ by less than 0.001s - the average across 10 runs of the stripped
> down LZO code is about 0.00133s where the LZO library (liblzo2) returns about
> even performance - average is 0.001s.
>
> A total difference of *ONE* *THIRD* of *ONE* *THOUSANDTH* of a second. With
> the better performance being in-kernel should bring, I can see no reason for
> a "big" difference.
>
> If anyone's interested in the code I used for the test, let me know and I'll
> make it available.

Yes, please do. It'd be nice if numbers are compared across arch's (LE,
BE, 32-bit, 64-bit) by others who have access to such boxes too.

Thanks,
Satyam
-
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/