From patchwork Thu Nov 26 16:51:41 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Pearson X-Patchwork-Id: 11934365 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 011E7C63697 for ; Thu, 26 Nov 2020 16:52:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A9A48221F7 for ; Thu, 26 Nov 2020 16:52:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391589AbgKZQwR (ORCPT ); Thu, 26 Nov 2020 11:52:17 -0500 Received: from mail1.bemta23.messagelabs.com ([67.219.246.4]:19790 "EHLO mail1.bemta23.messagelabs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391549AbgKZQwQ (ORCPT ); Thu, 26 Nov 2020 11:52:16 -0500 Received: from [100.112.1.102] (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256 bits)) by server-4.bemta.az-b.us-east-1.aws.symcld.net id 9D/00-42660-93DDFBF5; Thu, 26 Nov 2020 16:52:09 +0000 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprJKsWRWlGSWpSXmKPExsWS8eIhj67l3f3 xBvcuMFvsvy5h0bXQwGLh/VOsFl+/3Wa3eHN8OpPF8n39jBYfl3FYfO6YzGKxes8LZou1X+ax WZw5fYnVgdtj0swZzB47Z91l9/i1bQ2Lx+YVWh7zTgZ69LRtYvJ4v+8qm8eWq+0sHp83yQVwR rFm5iXlVySwZtw6/ICp4J9yRc/8VvYGxmeyXYxcHEIC/xklPjd0MUI4Dxklzl3+xt7FyMnBJq AtsWXLL7YuRg4OEQEZiQ9rPUFqmAUWMEl8ub6GFaRGWCBR4s+S94wgNouAqsSansVg9bwC1hJ bXouAhCUE5CWe9i5nBrE5gUrOdD1mAbGFBFQk7j9YwgZi8woISpyc+QQszgxU37x1NjOELSFx 8MULZog5ChKTF1xlgrATJJa9vMM8gVFgFpL2WUjaZyFpX8DIvIrRLKkoMz2jJDcxM0fX0MBA1 9DQSNcAxNJLrNJN0ist1k1NLC7RNdRLLC/WK67MTc5J0ctLLdnECIyxlAKGlB2Md19/0DvEKM nBpCTKu2TP/nghvqT8lMqMxOKM+KLSnNTiQ4wyHBxKErzH7wDlBItS01Mr0jJzgPEOk5bg4FE S4f19GyjNW1yQmFucmQ6ROsWoKCXOuw0kIQCSyCjNg2uDpZhLjLJSwryMDAwMQjwFqUW5mSWo 8q8YxTkYlYR5t4Ns58nMK4Gb/gpoMRPQ4umce0AWlyQipKQamJweGMyP49Js62Z6f16gabvND Dalww62c8Ujf+XdvT1tceGBPQcU/1g+va/h809ns5PWhUsWOmtuf3rfFH510+ZD1lwLz8/Y22 iis2a2+yfFu9y9uozvu+KX7/A19N8m+2pjZ8ZkLdWYq+fszjDGLhMWiS9ZOdGlzV4r+e9V56I pC0IXT63VO8/fx/rlpfvVmVLpj1fo/lTaG7OzoO6CHJMk7w1LtcYFyj9LHi6f5/04eU981R3B bQZSbL/nx5yO26GUNXOyfSZ3YHjRNdt1Tz3L8s/sFIyUm6rMaSX70COrWdJtf23Q2Y6e65NPL Hq4VKsuvmR/ZmHlfD/XDRpc0ia3Ek1F9avZbr5/mD2hXomlOCPRUIu5qDgRAGL6ThqsAwAA X-Env-Sender: markpearson@lenovo.com X-Msg-Ref: server-13.tower-395.messagelabs.com!1606409528!181385!1 X-Originating-IP: [104.232.225.12] X-SYMC-ESS-Client-Auth: outbound-route-from=pass X-StarScan-Received: X-StarScan-Version: 9.60.3; banners=-,-,- X-VirusChecked: Checked Received: (qmail 8530 invoked from network); 26 Nov 2020 16:52:09 -0000 Received: from unknown (HELO lenovo.com) (104.232.225.12) by server-13.tower-395.messagelabs.com with ECDHE-RSA-AES256-GCM-SHA384 encrypted SMTP; 26 Nov 2020 16:52:09 -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 C987F99A393690D97FF3; Thu, 26 Nov 2020 11:52:08 -0500 (EST) Received: from localhost.home (10.64.80.205) 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; Thu, 26 Nov 2020 08:52:05 -0800 From: Mark Pearson To: CC: , , , , , , , , , , Subject: [PATCH v4 1/3] Documentation: Add documentation for new platform_profile sysfs attribute Date: Thu, 26 Nov 2020 11:51:41 -0500 Message-ID: <20201126165143.32776-1-markpearson@lenovo.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: References: MIME-Version: 1.0 X-Originating-IP: [10.64.80.205] 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 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 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 Changes in v3 & v4: - version bump along with rest of patch series .../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.