From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758013Ab3DBWsU (ORCPT ); Tue, 2 Apr 2013 18:48:20 -0400 Received: from hydra.sisk.pl ([212.160.235.94]:50394 "EHLO hydra.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757983Ab3DBWsP (ORCPT ); Tue, 2 Apr 2013 18:48:15 -0400 From: "Rafael J. Wysocki" To: Stratos Karafotis Cc: Viresh Kumar , cpufreq@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 linux-next] cpufreq: ondemand: Calculate gradient of CPU load to early increase frequency Date: Wed, 03 Apr 2013 00:55:51 +0200 Message-ID: <31773720.6bVyeZQsYt@vostro.rjw.lan> User-Agent: KMail/4.9.5 (Linux/3.9.0-rc4+; KDE/4.9.5; x86_64; ; ) In-Reply-To: <515AFDFA.8090108@semaphore.gr> References: <51253715.7080600@semaphore.gr> <1544183.cq3KaqH8x3@vostro.rjw.lan> <515AFDFA.8090108@semaphore.gr> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday, April 02, 2013 06:49:14 PM Stratos Karafotis wrote: > On 04/02/2013 04:50 PM, Rafael J. Wysocki wrote: > > Do you have any numbers indicating that this actually makes things better? > > > > Rafael > > No, I don't. > The expected behaviour after this patch is to "force" max frequency few sampling periods earlier. > The idea was to increase system responsiveness especially on 'small' embedded systems (phones for example). > > Actually, I thought to provide some numbers but I had no idea how to measure this. > > Would it be enough to provide the number of times that the CPU increases frequency > because of early_demand versus the total number of increments? I think it would be better to check if your approach leads to a better behavior as far as energy savings are concerned. If it actually is worse, then I don't see a reason to apply it. Thanks, Rafael -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.