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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 2407BC33CAA for ; Mon, 20 Jan 2020 14:53:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 048A422527 for ; Mon, 20 Jan 2020 14:53:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728928AbgATOxo (ORCPT ); Mon, 20 Jan 2020 09:53:44 -0500 Received: from foss.arm.com ([217.140.110.172]:33146 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727289AbgATOxn (ORCPT ); Mon, 20 Jan 2020 09:53:43 -0500 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 BAFF530E; Mon, 20 Jan 2020 06:53:42 -0800 (PST) Received: from [192.168.0.7] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5FF8C3F52E; Mon, 20 Jan 2020 06:53:36 -0800 (PST) Subject: Re: [PATCH 1/4] PM / EM: and devices to Energy Model To: lukasz.luba@arm.com, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, dri-devel@lists.freedesktop.org, linux-omap@vger.kernel.org, linux-mediatek@lists.infradead.org, linux-arm-msm@vger.kernel.org, linux-imx@nxp.com Cc: Morten.Rasmussen@arm.com, Chris.Redpath@arm.com, ionela.voinescu@arm.com, javi.merino@arm.com, cw00.choi@samsung.com, b.zolnierkie@samsung.com, rjw@rjwysocki.net, sudeep.holla@arm.com, viresh.kumar@linaro.org, nm@ti.com, sboyd@kernel.org, rui.zhang@intel.com, amit.kucheria@verdurent.com, daniel.lezcano@linaro.org, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, rostedt@goodmis.org, qperret@google.com, bsegall@google.com, mgorman@suse.de, shawnguo@kernel.org, s.hauer@pengutronix.de, festevam@gmail.com, kernel@pengutronix.de, khilman@kernel.org, agross@kernel.org, bjorn.andersson@linaro.org, robh@kernel.org, matthias.bgg@gmail.com, steven.price@arm.com, tomeu.vizoso@collabora.com, alyssa.rosenzweig@collabora.com, airlied@linux.ie, daniel@ffwll.ch, patrick.bellasi@matbug.net References: <20200116152032.11301-1-lukasz.luba@arm.com> <20200116152032.11301-2-lukasz.luba@arm.com> From: Dietmar Eggemann Message-ID: <17b77e0c-9455-0479-d37b-c57717c784c7@arm.com> Date: Mon, 20 Jan 2020 15:53:35 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <20200116152032.11301-2-lukasz.luba@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 16/01/2020 16:20, lukasz.luba@arm.com wrote: > From: Lukasz Luba > > Add support of other devices into the Energy Model framework not only the > CPUs. Change the interface to be more unified which can handle other > devices as well. [...] > -The source of the information about the power consumed by CPUs can vary greatly > +The source of the information about the power consumed by devices can vary greatly > from one platform to another. These power costs can be estimated using > devicetree data in some cases. In others, the firmware will know better. > Alternatively, userspace might be best positioned. And so on. In order to avoid > @@ -26,7 +28,7 @@ framework, and interested clients reading the data from it:: > | Thermal (IPA) | | Scheduler (EAS) | | Other | > +---------------+ +-----------------+ +---------------+ > | | em_pd_energy() | > - | | em_cpu_get() | > + | em_dev_get() | em_cpu_get() | Looked really hard but can't find a em_dev_get() in the code? You mean em_get_pd() ? And why em_get_pd() and not em_pd_get()? > +---------+ | +---------+ > | | | > v v v > @@ -47,12 +49,12 @@ framework, and interested clients reading the data from it:: > | Device Tree | | Firmware | | ? | > +--------------+ +---------------+ +--------------+ [...] > +There is two API functions which provide the access to the energy model: > +em_cpu_get() which takes CPU id as an argument and em_dev_get() with device > +pointer as an argument. It depends on the subsystem which interface it is > +going to use. Would be really nice if this wouldn't be required. We should really aim for 1 framework == 1 set of interfaces. What happens if someone calls em_get_pd() on a CPU EM? E.g: static struct perf_domain *pd_init(int cpu) { - struct em_perf_domain *obj = em_cpu_get(cpu); + struct device *dev = get_cpu_device(cpu); + struct em_perf_domain *obj = em_pd_get(dev); struct perf_domain *pd; Two versions of one functionality will confuse API user from the beginning ... [...] > +enum em_type { > + EM_SIMPLE, > + EM_CPU, > +}; s/EM_SIMPLE/EM_DEV ? Right now I only see energy models and _one_ specific type (the CPU EM). So a tag 'is a CPU EM' would suffice. No need for EM_SIMPE ... [...]