From patchwork Mon Jan 22 17:44:07 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Aishwarya Pant X-Patchwork-Id: 10178957 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id A47D3602B7 for ; Mon, 22 Jan 2018 17:44:18 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9061826E54 for ; Mon, 22 Jan 2018 17:44:18 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8407527F7F; Mon, 22 Jan 2018 17:44:18 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, FREEMAIL_FROM, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D2E7826E54 for ; Mon, 22 Jan 2018 17:44:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751121AbeAVRoQ (ORCPT ); Mon, 22 Jan 2018 12:44:16 -0500 Received: from mail-pf0-f196.google.com ([209.85.192.196]:46855 "EHLO mail-pf0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751040AbeAVRoP (ORCPT ); Mon, 22 Jan 2018 12:44:15 -0500 Received: by mail-pf0-f196.google.com with SMTP id y5so7616954pff.13; Mon, 22 Jan 2018 09:44:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:mime-version:content-disposition :user-agent; bh=jxZfBhSC8jyHgY3Gxws8ZLfr4XDT4gLY8SUvV/a9Y1I=; b=vMwFw63ye2uu7JLq4yVBnEs9UgZVJ0pdHZH5bph/P/GFS6guKCH7Aa/WFv8U27JXx1 /mqpsp3/ukfOPFo+XWc7OvrpQniAWIMaoJvUCGhnEFWwJDt9nwg6bh7kh+HTsdavqwFu QrY+ZUX74PeVNk+rwEZhn/HDbavlaYurctpAGDBiIUhx/lJ0+OzBlZo4dqQuQAuoXsaI g2RP9g5m8TPYwk7gnHz+jhnLB9tcPjXzRaASOSlUOaO+xZQSpxokQAYhnAjHpLAxa1+5 BkdhuY+pWvbCkWF13wJpidcVcMUtMiRCgm0dIGXJhypEHUitSvyLSZgp125jiV1XObEE YqcA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:mime-version :content-disposition:user-agent; bh=jxZfBhSC8jyHgY3Gxws8ZLfr4XDT4gLY8SUvV/a9Y1I=; b=sMeOAe/QH7aIqJW19PNg0lJFsSbOdVmyi3ughBbggeYMa0t7GS0OHuOFDklIc1IwAw a80WCkno/F0ZkGQIPCnYeUSm/yCr6HfiyCfnUMgXbSELcaqjAyp9u/jju9VOwlNIDZkq lVmg2tfMRfFFkMlcnSbJsDCWCrQ1OvlGtw6DFMOmUQCLCfaZTtWLdtr+17oDkRe9YHTk Vz2OeKY1/tHNqD3b1xiJ7lfkRsAh2YZIbJkpeJgiC4Llx0IJXAZa5A/+pJ0h6rPvVYxL jA+2dILoN5GuGQzJ1iZ+go4VJW9V9yWq6ExLvz9wyhawHhJUkcBm/j83ikxy8yCG0tSF zsFg== X-Gm-Message-State: AKwxytdCdiO/BNB7jdnkTEA/5uun/dR/n5Mv9mBUzT1PrgfJHlwXoenZ 7//JpNuSpZjUA8iMbcTA1ec= X-Google-Smtp-Source: AH8x226OR/WlaocNqSFQxYw7vXUrwcCiais/hLawkTVBwM+I2o5P34UDJKNRgrJdme9AGn7fNFSPjw== X-Received: by 2002:a17:902:bf41:: with SMTP id u1-v6mr3883596pls.92.1516643054572; Mon, 22 Jan 2018 09:44:14 -0800 (PST) Received: from mordor.localdomain ([49.205.216.57]) by smtp.gmail.com with ESMTPSA id u135sm26890717pgc.84.2018.01.22.09.44.10 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 22 Jan 2018 09:44:14 -0800 (PST) Date: Mon, 22 Jan 2018 23:14:07 +0530 From: Aishwarya Pant To: "Rafael J. Wysocki" , Daniel Lezcano , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Jonathan Corbet , Greg KH , linux-doc@vger.kernel.org Cc: Julia Lawall Subject: [PATCH v2] Documentation/ABI: update cpuidle sysfs documentationDaniel Lezcano , Message-ID: <20180122174407.GA21985@mordor.localdomain> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Update cpuidle documentation using git logs and existing documentation in Documentation/cpuidle/sysfs.txt. This might be useful for scripting and tracking changes in the ABI. Signed-off-by: Aishwarya Pant --- Change in v2: - Merge cpuidle_sysfs_switch attributes' description with the previous entry. Documentation/ABI/testing/sysfs-devices-system-cpu | 80 +++++++++++++++++++++- 1 file changed, 78 insertions(+), 2 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index bfd29bc8d37a..113402ca9397 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -108,6 +108,8 @@ Description: CPU topology files that describe a logical CPU's relationship What: /sys/devices/system/cpu/cpuidle/current_driver /sys/devices/system/cpu/cpuidle/current_governor_ro + /sys/devices/system/cpu/cpuidle/available_governors + /sys/devices/system/cpu/cpuidle/current_governor Date: September 2007 Contact: Linux kernel mailing list Description: Discover cpuidle policy and mechanism @@ -119,13 +121,87 @@ Description: Discover cpuidle policy and mechanism Idle policy (governor) is differentiated from idle mechanism (driver) - current_driver: displays current idle mechanism + System global cpuidle related information and tunables are under + /sys/devices/system/cpu/cpuidle. Briefly, the attributes are: - current_governor_ro: displays current idle policy + current_driver: (RO) displays current idle mechanism + + current_governor_ro: (RO) displays current idle policy + + With the cpuidle_sysfs_switch boot option enabled (meant for + developer testing), the following three attributes are visible + instead: + + current_driver: same as described above + + available_governors: (RO) displays a space separated list of + available governors + + current_governor: (RW) displays current idle policy. Users can + switch the governor at runtime by writing to this file. See files in Documentation/cpuidle/ for more information. +What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/name + /sys/devices/system/cpu/cpuX/cpuidle/stateN/latency + /sys/devices/system/cpu/cpuX/cpuidle/stateN/power + /sys/devices/system/cpu/cpuX/cpuidle/stateN/time + /sys/devices/system/cpu/cpuX/cpuidle/stateN/usage +Date: September 2007 +KernelVersion: v2.6.24 +Contact: Linux kernel mailing list +Description: + The directory /sys/devices/system/cpu/cpuX/cpuidle contains per + logical CPU specific cpuidle information for each online cpu X. + The processor idle states which are available for use have the + following attributes: + + name: (RO) Name of the idle state (string). + + latency: (RO) The latency to exit out of this idle state (in + microseconds). + + power: (RO) The power consumed while in this idle state (in + milliwatts). + + time: (RO) The total time spent in this idle state (in microseconds). + + usage: (RO) Number of times this state was entered (a count). + + +What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/desc +Date: February 2008 +KernelVersion: v2.6.25 +Contact: Linux kernel mailing list +Description: + (RO) A small description about the idle state (string). + + +What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/disable +Date: March 2012 +KernelVersion: v3.10 +Contact: Linux kernel mailing list +Description: + (RW) Option to disable this idle state (bool). The behavior and + the effect of the disable variable depends on the implementation + of a particular governor. In the ladder governor, for example, + it is not coherent, i.e. if one is disabling a light state, then + all deeper states are disabled as well, but the disable variable + does not reflect it. Likewise, if one enables a deep state but a + lighter state still is disabled, then this has no effect. + + +What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/residency +Date: March 2014 +KernelVersion: v3.15 +Contact: Linux kernel mailing list +Description: + (RO) Display the target residency i.e. the minimum amount of + time (in microseconds) this cpu should spend in this idle state + to make the transition worth the effort. + + What: /sys/devices/system/cpu/cpu#/cpufreq/* Date: pre-git history Contact: linux-pm@vger.kernel.org