From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 42B43C04A95 for ; Wed, 28 Sep 2022 17:10:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234326AbiI1RKG (ORCPT ); Wed, 28 Sep 2022 13:10:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55804 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230431AbiI1RKD (ORCPT ); Wed, 28 Sep 2022 13:10:03 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 33950915E4 for ; Wed, 28 Sep 2022 10:10:02 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9EB0A143D; Wed, 28 Sep 2022 10:10:08 -0700 (PDT) Received: from [192.168.178.6] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 170793F792; Wed, 28 Sep 2022 10:09:59 -0700 (PDT) Message-ID: Date: Wed, 28 Sep 2022 19:09:40 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [RFC PATCH 0/1] sched/pelt: Change PELT halflife at runtime Content-Language: en-US To: Jian-Min Liu , Ingo Molnar , Peter Zijlstra , Vincent Guittot , Morten Rasmussen , Vincent Donnefort Cc: Quentin Perret , Patrick Bellasi , Abhijeet Dharmapurikar , Qais Yousef , linux-kernel@vger.kernel.org, Jonathan JMChen , Kajetan Puchalski References: <20220829055450.1703092-1-dietmar.eggemann@arm.com> <0f82011994be68502fd9833e499749866539c3df.camel@mediatek.com> From: Dietmar Eggemann In-Reply-To: <0f82011994be68502fd9833e499749866539c3df.camel@mediatek.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org + Kajetan Puchalski On 20/09/2022 16:07, Jian-Min Liu wrote: > > Update some test data in android phone to support switching PELT HL > is helpful functionality. > > We switch runtime PELT HL during runtime by difference scenario e.g. > pelt8 in playing game, pelt32 in camera video. Support runntime > switching PELT HL is flexible for different workloads. > > the below table show performance & power data points: > > --------------------------------------------------------------------- > --| | PELT > halflife | > | |----------------------------------------------| > | | 32 | 16 | 8 | > | |----------------------------------------------| > | | avg min avg | avg min avg | avg min avg| > | Scenarios | fps fps pwr | fps fps pwr | fps fps pwr| > |---------------------------------------------------------------------| > | HOK game 60fps | 100 100 100 | 105 *134* 102 | 104 *152* 106| > | HOK game 90fps | 100 100 100 | 101 *114* 101 | 103 *129* 105| > | HOK game 120fps | 100 100 100 | 102 *124* 102 | 105 *134* 105| > | FHD video rec. 60fps | 100 100 100 | n/a n/a n/a | 100 100 103| > | Camera snapshot | 100 100 100 | n/a n/a n/a | 100 100 102| > ----------------------------------------------------------------------- > > HOK ... Honour Of Kings, Video game > FHD ... Full High Definition > fps ... frame per second > pwr ... power consumption > > table values are in % I assume that you are specifically interested in those higher min fps numbers which can be achieved with a tolerable energy consumption increase when running the game with 16ms or even 8ms PELT halflife. We see a similar effect when running the UI performance benchmark Jankbench. So you need this runtime-switchable PELT multiplier. Would this sched feature interface: https://lkml.kernel.org/r/YwyOzgbbUbB+JmSH@hirez.programming.kicks-ass.net be sufficient for you? People don't like to support `changing PELT halflife` via an official sysctl. [...]