From patchwork Fri Dec 18 17:47:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Pearson X-Patchwork-Id: 11982703 X-Patchwork-Delegate: rjw@sisk.pl 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,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 BCD72C2D0E4 for ; Fri, 18 Dec 2020 17:54:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 87DF323B5D for ; Fri, 18 Dec 2020 17:54:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728213AbgLRRyd (ORCPT ); Fri, 18 Dec 2020 12:54:33 -0500 Received: from mail1.bemta24.messagelabs.com ([67.219.250.113]:12905 "EHLO mail1.bemta24.messagelabs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725800AbgLRRyc (ORCPT ); Fri, 18 Dec 2020 12:54:32 -0500 Received: from [100.112.132.72] (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256 bits)) by server-2.bemta.az-b.us-west-2.aws.symcld.net id 42/98-28581-F8BECDF5; Fri, 18 Dec 2020 17:49:03 +0000 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprFKsWRWlGSWpSXmKPExsWSLveKTbf/9Z1 4gzmTJC32X5ew6FpoYLHw/ilWi6/fbrNbvDk+ncli+b5+RoumziY2i88dk1ksVu95wWyx9ss8 Noszpy+xOnB7TJo5g9lj56y77B6/tq1h8di8Qstj3slAj562TUwe7/ddZfPYcrWdxePzJrkAz ijWzLyk/IoE1ozJ97UKnutUXJ2zla2B8aZaFyMXh5DAf0aJy5+uskA4DxklNsxrY+pi5ORgE9 CW2LLlF1sXIweHiICMxIe1niBhZoFtTBK9+4JAbGGBRInOG9NYQWwWAVWJC70LwWxeARuJna3 72UFsCQF5iae9y5lBbE6gmjNdj1lAbCEBFYn7D5awQdQLSpyc+YQFYr68RPPW2cwQtoTEwRcv mCHmKEgsevafDcJOkFj28g7zBEaBWUjaZyFpn4WkfQEj8ypG86SizPSMktzEzBxdQwMDXUNDI 11DYyNdM2O9xCrdJL3SYt3y1OISXSO9xPJiveLK3OScFL281JJNjMAoSylosd/BOOPNB71DjJ IcTEqivFoP7sQL8SXlp1RmJBZnxBeV5qQWH2KU4eBQkuAtfwWUEyxKTU+tSMvMAUY8TFqCg0d JhDfoJVCat7ggMbc4Mx0idYpRUUqcd9NDoIQASCKjNA+uDZZkLjHKSgnzMjIwMAjxFKQW5WaW oMq/YhTnYFQS5g0EGc+TmVcCN/0V0GImoMV8M26DLC5JREhJNTD1FOjo1MjtdHkup2Y9J6yA5 5CG3kYrtZtH+g6zFZ/xWxt1wPnpAk/tn+vrhLPn3XjBesda5+UW2S2s/2ILHASTV+4I379ZiK lVeAHvpH9l67VnT/xyxdn94z0PzkvzvAJatrTcKD9Saxv0fOvq4/VOgZtjXiROKGOR3y7Hs27 eU1aRqqqsRKeGG0eKdl/tXsbfX/xMzKYtp3rW2RVNc77KbGvNrAuq/qbTckb0jtvmncGhDScj 2+ccvadqLr07V2Nr6sx1DS+/hjSed3fjecoVZnql45i09rl1m66dsTxxdkdT6UpNtZP/9r7Ym Ohh5hC+TFr7QfDHKa8vRS15yZYz05nRzYGta9kdhTM/VE8psRRnJBpqMRcVJwIA7u0oQa0DAA A= X-Env-Sender: markpearson@lenovo.com X-Msg-Ref: server-23.tower-355.messagelabs.com!1608313741!2698!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 17089 invoked from network); 18 Dec 2020 17:49:03 -0000 Received: from unknown (HELO lenovo.com) (103.30.234.6) by server-23.tower-355.messagelabs.com with ECDHE-RSA-AES256-GCM-SHA384 encrypted SMTP; 18 Dec 2020 17:49:03 -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 DE37AB9277B14558C298; Sat, 19 Dec 2020 01:48:58 +0800 (CST) Received: from localhost.home (10.64.89.183) 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; Fri, 18 Dec 2020 09:48:53 -0800 From: Mark Pearson To: CC: , , , , , , , , , , , Subject: [PATCH v7 1/3] Documentation: Add documentation for new platform_profile sysfs attribute Date: Fri, 18 Dec 2020 12:47:57 -0500 Message-ID: <20201218174759.667457-1-markpearson@lenovo.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: References: MIME-Version: 1.0 X-Originating-IP: [10.64.89.183] 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, v5 - version bump along with rest of patch series Changes in v6: - Split sysfs-platform_profile.rs into ABI text and then admin guide in userspace-api section. Hope this is correct - I'm guessing a bit. Changes in v7: - Correct available_choices to platform_profile_choices - Improve phrasing as recommended by review .../ABI/testing/sysfs-platform_profile | 24 ++++++++++ Documentation/userspace-api/index.rst | 1 + .../userspace-api/sysfs-platform_profile.rst | 44 +++++++++++++++++++ 3 files changed, 69 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-platform_profile create mode 100644 Documentation/userspace-api/sysfs-platform_profile.rst diff --git a/Documentation/ABI/testing/sysfs-platform_profile b/Documentation/ABI/testing/sysfs-platform_profile new file mode 100644 index 000000000000..9d6b89b66cca --- /dev/null +++ b/Documentation/ABI/testing/sysfs-platform_profile @@ -0,0 +1,24 @@ +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 + platform_profile_choices changes the profile to the new value. diff --git a/Documentation/userspace-api/index.rst b/Documentation/userspace-api/index.rst index acd2cc2a538d..d29b020e5622 100644 --- a/Documentation/userspace-api/index.rst +++ b/Documentation/userspace-api/index.rst @@ -24,6 +24,7 @@ place where this information is gathered. ioctl/index iommu media/index + sysfs-platform_profile .. only:: subproject and html diff --git a/Documentation/userspace-api/sysfs-platform_profile.rst b/Documentation/userspace-api/sysfs-platform_profile.rst new file mode 100644 index 000000000000..046bf2f3ffd0 --- /dev/null +++ b/Documentation/userspace-api/sysfs-platform_profile.rst @@ -0,0 +1,44 @@ +===================================================================== +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 +platform configuration is often automatically adjusted to the current +conditions 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 the sysfs-platform_profile ABI 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 sysfs-platform_profile ABI documentation. + +