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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 9E93FC433EF for ; Tue, 29 Mar 2022 13:41:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To:Subject: MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=5mypG29dMAJWCrspq+ZHXggzM/H9U6N99t/yjKfFehE=; b=J41t5OMtb1mpIQ xgR59mO2n6McVnE8R7w19yc9jBYiAk088odmw+j4B+eH6KIUKZFFRuLT7oy3Xp5Fjb8CHVPJcSZI2 Om+BqExsbAZ+AWTVg/j7G541ibXiTGNwfl1bKmh8KL4iyHsbLR/QvEtWFOW9Awa2giuELXFT5arE4 FYHJL8fqQQXnaUDNL6XkyD974a+pVqUGIaw5dQOaI3D+f10V1cstRUUesxh95YTeRcLt3s/68e2N3 eF/gKUr1fO5qPllMniQ23/6oWvwrSDlVfhyvXAFcfqjSj1gEPOJ1XnKkE1CMIBwsFv95hLQJyBVc2 hTpGcr8NCdbqWbtbwkCw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nZC4k-00COVx-Gm; Tue, 29 Mar 2022 13:39:58 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nZC4g-00COUj-8c; Tue, 29 Mar 2022 13:39:55 +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 7055D23A; Tue, 29 Mar 2022 06:39:53 -0700 (PDT) Received: from [10.57.7.161] (unknown [10.57.7.161]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8AC333F73B; Tue, 29 Mar 2022 06:39:50 -0700 (PDT) Message-ID: <85f6a95e-24c3-0119-d43f-e57a3996280d@arm.com> Date: Tue, 29 Mar 2022 14:39:48 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [0/8] Introduce support for artificial Energy Model Content-Language: en-US To: Cristian Marussi Cc: linux-kernel@vger.kernel.org, dietmar.eggemann@arm.com, Pierre.Gondois@arm.com, ionela.voinescu@arm.com, viresh.kumar@linaro.org, rafael@kernel.org, daniel.lezcano@linaro.org, linux-pm@vger.kernel.org, mka@chromium.org, nm@ti.com, sboyd@kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, sudeep.holla@arm.com, matthias.bgg@gmail.com References: <20220316235211.29370-1-lukasz.luba@arm.com> From: Lukasz Luba In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220329_063954_435538_152864C7 X-CRM114-Status: GOOD ( 30.83 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Cristian, On 3/29/22 14:29, Cristian Marussi wrote: > On Wed, Mar 16, 2022 at 11:52:03PM +0000, Lukasz Luba wrote: >> Hi all, >> > > Hi Lukasz, > >> This patch set adds new callback and support for artificial Energy Model (EM). >> The new EMs have artificially generated performance states. >> Such EMs can be created from lean information sources, such >> as the relative energy efficiency between CPUs. The ACPI based >> platforms provide this information >> (ACPI 6.4, s5.2.12.14 'GIC CPU Interface (GICC) Structure' >> 'Processor Power efficiency Class' field). >> >> Artificial EMs might require to directly provide the 'cost' of >> the generated performance state. This patch set adds a new callback >> .get_cost() for this. The EM framework does not force any model >> or formula, it's up to the platform code. >> >> Artificial EMs aim to leverage the Energy Aware Scheduler >> (EAS). Other frameworks relying on performance states >> information (i.e. IPA/DTPM) must be informed of the >> EM type and might be prevented from using it. This patch >> sets also does this by introducing a new flag: >> EM_PERF_DOMAIN_ARTIFICIAL. >> >> The patch set is based on current linux-next, where some >> changes to OPP & EM are queuing. >> >> The patch set also contains (patch 7/8 and patch 8/8) logic which prevents >> two EM's client frameworks from using this new EM type. Some other approach, >> using 'milli-watts', has been proposed and discussed, but refused [1]. >> This new flag is more precised and should not leave space for >> wrong interpretation. >> >> Shortly after this patch set you will see a patch set implementing the >> platform code and registering this new EM. >> > > Just to let you know that in the few days I'm going to post the first > chunk of some SCMIv3.1 additions that includes also (as you probably > know) the SCMI Perf protocol support for reporting perf_domain costs in > micro-watts and not only in milli-watts. > > Given that it does not seem that as of now the em_ API used by the SCMI > cpufreq driver can make use of this new scale (and being not at all > familiar with EM/EAS for sure :P), the SCMIv3.1 'Perf micro-watts' patch > which I will post (I'll CC you) does NOT expose any new interface but only > takes care to store the new micro-watts capability internally in a flag > (if advertised by an SCMIv3.1 backend server), so that, basically, you'll > keep seeing from the SCMI cpufreq driver that the scale is milli-watt > (when milli-watts are used of course) or non-milli-watt (for abstract and > micro-watts scales). Sounds good! > > This is intended to be of course a first step, laying out just the bare > minimum commmon internal SCMI support, until we figure out how to properly > expose this from the SCMI Perf in order to make it usable for EM. > (if neeeded at all). > I had such a patch for the EM, to keep the power in micro-Watts. We can glue these two layers (high level EM and low layer SCMI perf). Let's sort it out. Regards, Lukasz _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel