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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 754DDC433F5 for ; Thu, 6 Sep 2018 06:57:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 26F8D2075E for ; Thu, 6 Sep 2018 06:57:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 26F8D2075E 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-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726575AbeIFLbC (ORCPT ); Thu, 6 Sep 2018 07:31:02 -0400 Received: from foss.arm.com ([217.140.101.70]:39478 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725919AbeIFLbB (ORCPT ); Thu, 6 Sep 2018 07:31:01 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 46E387A9; Wed, 5 Sep 2018 23:57:04 -0700 (PDT) Received: from [0.0.0.0] (e107985-lin.Emea.Arm.com [10.4.12.239]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 2B11C3F557; Wed, 5 Sep 2018 23:56:47 -0700 (PDT) Subject: Re: [PATCH v6 04/14] PM / EM: Expose the Energy Model in sysfs To: Quentin Perret , peterz@infradead.org, rjw@rjwysocki.net, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org Cc: gregkh@linuxfoundation.org, mingo@redhat.com, morten.rasmussen@arm.com, chris.redpath@arm.com, patrick.bellasi@arm.com, valentin.schneider@arm.com, vincent.guittot@linaro.org, thara.gopinath@linaro.org, viresh.kumar@linaro.org, tkjos@google.com, joel@joelfernandes.org, smuckle@google.com, adharmap@codeaurora.org, skannan@codeaurora.org, pkondeti@codeaurora.org, juri.lelli@redhat.com, edubezval@gmail.com, srinivas.pandruvada@linux.intel.com, currojerez@riseup.net, javi.merino@kernel.org References: <20180820094420.26590-1-quentin.perret@arm.com> <20180820094420.26590-5-quentin.perret@arm.com> From: Dietmar Eggemann Message-ID: Date: Wed, 5 Sep 2018 23:56:43 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20180820094420.26590-5-quentin.perret@arm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/20/2018 02:44 AM, Quentin Perret wrote: > Expose the Energy Model (read-only) of all performance domains in sysfs > for convenience. To do so, add a kobject to the CPU subsystem under the > umbrella of which a kobject for each performance domain is attached. > > The resulting hierarchy is as follows for a platform with two > performance domains for example: > > /sys/devices/system/cpu/energy_model > ├── pd0 > │   ├── cost > │   ├── cpus > │   ├── frequency > │   └── power cpus (cpumask of the perf domain), frequency (OPP's of the perf domain) and power (values at those OPP's) are somehow easy to grasp, cost is definitely not. You have this nice description in em_pd_energy() what cost actually is. IMHO, might be worth repeating this at least in the patch header here. [...]