From patchwork Sat Nov 14 15:01:00 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Pearson X-Patchwork-Id: 11905649 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=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 C00F8C63697 for ; Sat, 14 Nov 2020 15:01:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8A343206D4 for ; Sat, 14 Nov 2020 15:01:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726884AbgKNPB2 (ORCPT ); Sat, 14 Nov 2020 10:01:28 -0500 Received: from mail1.bemta24.messagelabs.com ([67.219.250.116]:53539 "EHLO mail1.bemta24.messagelabs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726522AbgKNPB1 (ORCPT ); Sat, 14 Nov 2020 10:01:27 -0500 Received: from [100.112.133.178] (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256 bits)) by server-5.bemta.az-b.us-west-2.aws.symcld.net id D2/BF-18625-341FFAF5; Sat, 14 Nov 2020 15:01:23 +0000 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFupnleJIrShJLcpLzFFi42JJl3vFpuv8cX2 8wcMTkhb7r0tYdC00sFh4/xSrxddvt9kt3hyfzmSxfF8/o0VTZxObxeeOySwWq/e8YLY4c/oS qwOXx6SZM5g9ds66y+7xa9saFo/NK7Q85p0M9Hi/7yqbx5ar7SwenzfJBXBEsWbmJeVXJLBmv Fs5i7Vgt3LFxZ1/2BoYN8l2MXJxCAn8Z5S4MmE+O4Tzg1HixL1m1i5GTg42AW2JLVt+sXUxcn CICMhIfFjrCVLDLNDOJLH62GM2kBphgUSJ2+vus4DUsAioSmw/yQIS5hWwkVj/Yg3YGAkBeYm Zl76zg9icQCVnuh6D1QgJqEjcf7CEDaJeUOLkzCdgcWag+uats5khbAmJgy9eMIOMlxBQkLgz oxBiZILEspd3mCcwCsxC0j0LSfcsJN0LGJlXMZolFWWmZ5TkJmbm6BoaGOgaGhrpGhob6VroJ VbpJumVFuuWpxaX6BrpJZYX6xVX5ibnpOjlpZZsYgTGU0pBC8cOxsOvP+gdYpTkYFIS5f2wen 28EF9SfkplRmJxRnxRaU5q8SFGGQ4OJQneCR+AcoJFqempFWmZOcDYhklLcPAoifCygaR5iws Sc4sz0yFSpxgVpcR520ASAiCJjNI8uDZYOrnEKCslzMvIwMAgxFOQWpSbWYIq/4pRnINRSZhX BWQKT2ZeCdz0V0CLmYAWfzBbA7K4JBEhJdXAFFR55HqwQqSdwa7cLw3LinOLZ06+wX1/zXnfi RnXXVrtVufFsbDn7pFW+bvz68+InI3PZ3m8E68qkctfwhjJd63F/8wJJ7fjpfy1s+af0Gk1Nj vg514l2vBIuNG7LdUhYZKGv/jG/2UnHuYuCXgjKvW07ca0/j2bmf9rpV++5vRu+VGZ1XMt+Z1 e3Q7b/L0hkNmicVP21qmP7to6ti3zvJAr88WLoWxDgH8CI/9z92m3eDbN5XNTev2MxUZLb+mO /28eLb1mksTZfdg4uHv//4IXtXnpwVZrYmcqnFJYZXCkKMTz9xSDkPOWa68/mB/51p/nvZtAx /nVN4sUX7odlHQ8aTQv2Nr151ob/8llSizFGYmGWsxFxYkABPbfTqIDAAA= X-Env-Sender: markpearson@lenovo.com X-Msg-Ref: server-30.tower-346.messagelabs.com!1605366080!52312!1 X-Originating-IP: [103.30.234.6] X-SYMC-ESS-Client-Auth: outbound-route-from=pass X-StarScan-Received: X-StarScan-Version: 9.60.3; banners=-,-,- X-VirusChecked: Checked Received: (qmail 768 invoked from network); 14 Nov 2020 15:01:23 -0000 Received: from unknown (HELO lenovo.com) (103.30.234.6) by server-30.tower-346.messagelabs.com with ECDHE-RSA-AES256-GCM-SHA384 encrypted SMTP; 14 Nov 2020 15:01:23 -0000 Received: from reswpmail04.lenovo.com (unknown [10.62.32.23]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by Forcepoint Email with ESMTPS id 46EE988AE034C2D8B4FC; Sat, 14 Nov 2020 23:01:18 +0800 (CST) Received: from banther-ThinkPad-X1-Carbon-Gen-8.home (10.38.56.206) by reswpmail04.lenovo.com (10.62.32.23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2044.4; Sat, 14 Nov 2020 07:01:15 -0800 From: Mark Pearson To: CC: , , , , , , , , , Subject: [PATCH v2 1/3] Documentation: Add documentation for new platform_profile sysfs attribute Date: Sat, 14 Nov 2020 10:01:00 -0500 Message-ID: <20201114150102.340618-1-markpearson@lenovo.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 X-Originating-IP: [10.38.56.206] X-ClientProxiedBy: reswpmail04.lenovo.com (10.62.32.23) To reswpmail04.lenovo.com (10.62.32.23) Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org On modern systems the platform performance, temperature, fan and other hardware related characteristics are often dynamically configurable. The profile is often automatically adjusted to the load by somei automatic-mechanism (which may very well live outside the kernel). These auto platform-adjustment mechanisms often can be configured with one of several 'platform-profiles', with either a bias towards low-power consumption or towards performance (and higher power consumption and thermals). Introduce a new platform_profile sysfs API which offers a generic API for selecting the performance-profile of these automatic-mechanisms. Co-developed-by: Mark Pearson Signed-off-by: Mark Pearson Signed-off-by: Hans de Goede --- Changes in v2: - updated to rst format .../ABI/testing/sysfs-platform_profile.rst | 66 +++++++++++++++++++ 1 file changed, 66 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-platform_profile.rst diff --git a/Documentation/ABI/testing/sysfs-platform_profile.rst b/Documentation/ABI/testing/sysfs-platform_profile.rst new file mode 100644 index 000000000000..5f7b2a94409b --- /dev/null +++ b/Documentation/ABI/testing/sysfs-platform_profile.rst @@ -0,0 +1,66 @@ +======================================================================= + Platform Profile Selection (e.g. /sys/firmware/acpi/platform_profile) +======================================================================= + + +On modern systems the platform performance, temperature, fan and other +hardware related characteristics are often dynamically configurable. The +profile is often automatically adjusted to the load by some +automatic mechanism (which may very well live outside the kernel). + +These auto platform adjustment mechanisms often can be configured with +one of several platform profiles, with either a bias towards low power +operation or towards performance. + +The purpose of the platform_profile attribute is to offer a generic sysfs +API for selecting the platform profile of these automatic mechanisms. + +Note that this API is only for selecting the platform profile, it is +NOT a goal of this API to allow monitoring the resulting performance +characteristics. Monitoring performance is best done with device/vendor +specific tools such as e.g. turbostat. + +Specifically when selecting a high performance profile the actual achieved +performance may be limited by various factors such as: the heat generated +by other components, room temperature, free air flow at the bottom of a +laptop, etc. It is explicitly NOT a goal of this API to let userspace know +about any sub-optimal conditions which are impeding reaching the requested +performance level. + +Since numbers on their own cannot represent the multiple variables that a +profile will adjust (power consumption, heat generation, etc) this API +uses strings to describe the various profiles. To make sure that userspace +gets a consistent experience this API document defines a fixed set of +profile names. Drivers *must* map their internal profile representation +onto this fixed set. + + +If there is no good match when mapping then a new profile name may be +added. Drivers which wish to introduce new profile names must: + + 1. Explain why the existing profile names canot be used. + 2. Add the new profile name, along with a clear description of the + expected behaviour, to the documentation. + +:What: /sys/firmware/acpi/platform_profile_choices +:Date: October 2020 +:Contact: Hans de Goede +:Description: This file contains a space-separated list of profiles supported for this device. + + Drivers must use the following standard profile-names:: + + low-power: Low power consumption + cool: Cooler operation + quiet: Quieter operation + balanced: Balance between low power consumption and performance + performance: High performance operation + + Userspace may expect drivers to offer more than one of these + standard profile names. + +:What: /sys/firmware/acpi/platform_profile +:Date: October 2020 +:Contact: Hans de Goede +:Description: Reading this file gives the current selected profile for this + device. Writing this file with one of the strings from + available_profiles changes the profile to the new value.