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 X-Spam-Level: X-Spam-Status: No, score=0.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,URIBL_DBL_ABUSE_MALW,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 59FCCC2D0DB for ; Fri, 31 Jan 2020 17:31:11 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DB3782063A for ; Fri, 31 Jan 2020 17:31:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="CpIhyL1U" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DB3782063A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=cQqr48CgXArjLU35iz/+G6vUhc3tbLHmfXRygaoFSow=; b=CpIhyL1U2pM0elgEgvUZ0CY83 QanpJpk/7+azgyNaesCDV5f5tMKDrGyhauqt2GdGdz8PXj5xvICU8yklqaKEIQcuvDJtomnO9wKQD 3WV295ZhhVPyvAUhfBYdqYl/rKrqGVpUQxxun/+xKlHskmUcZd1LCpeuU0wodl8QgX1/bsu0tFiT3 cY/iRMlyecsEtjSAuCpIHUmhFTMhVeWYJMpKd9r5+jj3gfv7+TqQuGb0BypIHA9BFIx12CjgcdsRH HpaYbYWYHNNf3L8j/gYI/I08m7n/aEpeNXZJxP1Tm/GGQjN8Zny4qQrh5s0Qnu5QEyecyhMsqQSJp 5oBkoK2UA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1ixa8J-0002Jz-Ed; Fri, 31 Jan 2020 17:31:07 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1ixa8H-0002J2-1A for linux-arm-kernel@lists.infradead.org; Fri, 31 Jan 2020 17:31:06 +0000 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 003FCFEC; Fri, 31 Jan 2020 09:31:01 -0800 (PST) Received: from [10.37.12.54] (unknown [10.37.12.54]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0E9723F68E; Fri, 31 Jan 2020 09:30:49 -0800 (PST) Subject: Re: [PATCH 3/3] ARM: exynos_defconfig: Enable Energy Model framework To: Krzysztof Kozlowski References: <20200127215453.15144-1-lukasz.luba@arm.com> <20200127215453.15144-4-lukasz.luba@arm.com> From: Lukasz Luba Message-ID: Date: Fri, 31 Jan 2020 17:30:46 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200131_093105_166822_8735931F X-CRM114-Status: GOOD ( 22.03 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, devicetree@vger.kernel.org, "linux-samsung-soc@vger.kernel.org" , linux-pm@vger.kernel.org, =?UTF-8?Q?Bart=c5=82omiej_=c5=bbo=c5=82nierkiewicz?= , "linux-kernel@vger.kernel.org" , robh+dt@kernel.org, Chanwoo Choi , kyungmin.park@samsung.com, kgene@kernel.org, myungjoo.ham@samsung.com, dietmar.eggemann@arm.com, linux-arm-kernel@lists.infradead.org Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Krzysztof, On 1/31/20 1:16 PM, Krzysztof Kozlowski wrote: > On Mon, 27 Jan 2020 at 22:55, wrote: >> >> From: Lukasz Luba >> >> Enable the Energy Model (EM) brings possibility to use Energy Aware >> Scheduler (EAS). This compiles the EM but does not enable to run EAS in >> default. The EAS only works with SchedUtil - a CPUFreq governor which >> handles direct requests from the scheduler for the frequency change. Thus, >> to make EAS working in default, the SchedUtil governor should be >> configured as default CPUFreq governor. > > Full stop. That's enough of needed explanation of schedutil. OK > >> Although, the EAS might be enabled >> in runtime, when the EM is present for CPUs, the SchedUtil is compiled and >> then set as CPUFreq governor, i.e.: >> >> echo schedutil > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor >> echo schedutil > /sys/devices/system/cpu/cpu4/cpufreq/scaling_governor >> >> To check if EAS is ready to work, the read output from the command below >> should show '1': >> cat /proc/sys/kernel/sched_energy_aware >> >> To disable EAS in runtime simply 'echo 0' to the file above. > > Not related to this commit. If you were implemeting here > schedutil/EAS, then it makes sense to post all this. However what's > the point to describe it in every defconfig change? I will drop it. > >> Some test results, which stress the scheduler on Odroid-XU3: >> hackbench -l 500 -s 4096 >> With mainline code and with this patch set. > > Skip the last sentence - duplicated information. OK > >> >> The tests have been made with and without CONFIG_PROVE_LOCKING (PL) >> (which is set to =y in default exynos_defconfig) >> >> | this patch set | mainline > > The commit will be applied on its own branch so the meaning of "this > patch set" will be lost. Maybe just "before/after"? OK > >> |-----------------------------------------------|--------------- >> | performance | SchedUtil | SchedUtil | performance >> | governor | governor | governor | governor >> | | w/o EAS | w/ EAS | >> ----------------|---------------|---------------|---------------|--------------- >> hackbench w/ PL | 12.7s | 11.7s | 12.0s | 13.0s - 12.2s >> hackbench w/o PL| 9.2s | 8.1s | 8.2s | 9.2s - 8.4s > > Why does the performance different before and after this patch? Probably due to better locality and cache utilization. I can see that there is ~700k context switches vs ~450k and ~160k migrations vs ~50k. If you need to communicate two threads in different clusters, it will go through CCI. > > Mention - lower better (?). Space between number and unit... or better > mention [s] in column title. OK > > And last but not least: > Why this patch is separate from 1/3? I don't get the need of splitting them. As mentioned in response to patch 1/3. The fist patch would create MC domain, something different than Energy Model or EAS. The decisions in the scheduler would be different. I can merge 1/3 and 3/3 if you like, though. Regards, Lukasz > > Best regards, > Krzysztof > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel