From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S933426AbcBBR4j (ORCPT <rfc822;w@1wt.eu>);
	Tue, 2 Feb 2016 12:56:39 -0500
Received: from er-systems.de ([148.251.68.21]:51660 "EHLO er-systems.de"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S932097AbcBBR4i (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
	Tue, 2 Feb 2016 12:56:38 -0500
Date: Tue, 2 Feb 2016 18:56:33 +0100 (CET)
From: Thomas Voegtle <tv@lio96.de>
X-X-Sender: thomas@er-systems.de
To: "Longepe, Philippe" <philippe.longepe@intel.com>
cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "Gasparini, Stephane" <stephane.gasparini@intel.com>,
        "Wysocki, Rafael J" <rafael.j.wysocki@intel.com>
Subject: RE: Performance drop on Baytrail with 4.5-rc2
In-Reply-To: <8B729BF8A98FF048A53185F813A469D935B19D03@HASMSX105.ger.corp.intel.com>
Message-ID: <alpine.LSU.2.11.1602021854230.30638@er-systems.de>
References: <alpine.LSU.2.11.1602012122530.9114@er-systems.de> <8B729BF8A98FF048A53185F813A469D935B19D03@HASMSX105.ger.corp.intel.com>
User-Agent: Alpine 2.11 (LSU 23 2013-08-11)
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII; format=flowed
X-Virus-Checker-Version: clamassassin 1.2.4 with clamdscan / ClamAV 0.99/21336/Tue Feb  2 14:36:13 2016 signatures 55.
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Tue, 2 Feb 2016, Longepe, Philippe wrote:

> Hi Thomas,
>
> Yes, this new algorithm is intented to improve the performance versus power efficiency.
>
> Can you please provide us the exact instructions to reproduce your test ?


Hi,

my benchmark which I used is a little bit weird, so I tried to strip it
down a little.

The sample I used: https://32h.de/tv/test.vdr

I downloaded a static built version from
http://johnvansickle.com/ffmpeg/

I used the 64bit v2.8.6 binary.
   (md5 of ffmpeg binary: 2989d50b4b13cb1e549955522fd7d311)

And then I did:
time -p ./ffmpeg -v 0 -y -i test.vdr -preset veryfast -vf scale=320:208
-strict -2  -f mp4 /dev/null


Very interesting: you only get a difference between 4.5-rc2-with-revert 
and 4.5-rc2 with the downscaling. When you remove "-vf scale=320:208", you 
get the same times on 4.5-rc2-with-revert and the unmodified 4.5-rc2. See 
below:


with downscale
==============
4.5-rc2-with-revert
real 93.16
real 92.96
real 93.24

4.5-rc2
real 100.00
real 99.31
real 99.12


without "-vf scale=320:208"
===========================
4.5-rc2-with-revert
real 157.59
real 157.27
real 157.58

4.5-rc2
real 157.49
real 157.68
real 157.53


I'm confused, but I hope this helps? Do you need anything else?

Thanks in advance.


    Thomas