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=-8.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 371B8C43219 for ; Thu, 25 Apr 2019 15:33:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 56AD8206C0 for ; Thu, 25 Apr 2019 15:33:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="qqkAHy3q" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730304AbfDYPdm (ORCPT ); Thu, 25 Apr 2019 11:33:42 -0400 Received: from mail-pl1-f194.google.com ([209.85.214.194]:43138 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726181AbfDYPdk (ORCPT ); Thu, 25 Apr 2019 11:33:40 -0400 Received: by mail-pl1-f194.google.com with SMTP id n8so11269336plp.10; Thu, 25 Apr 2019 08:33:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=0U3DN21jJSHjryo32FyL3BVOe7dtJ75E6Tjlu2mOfww=; b=qqkAHy3qqfSAFBFz92IC52pWFnSIUoOnNwhcSJVlhgTyaZkxF7GhYcWIDHdiYcNsfM 9d3dMTrX4++p9jNFObtVmqJUCbbqPE3WnChz1oBbtMJvW7962ETZG7HG/QWTWPvA77Vl B96YxyBXV8v6pd8KLFq/KVei4dTgOdH7D0MHQOWZ+IoZz/hyuwRmKoMe/CfsimhQk6G8 NmqrzWTqQoh9hjWJhOKgtvDhMAj2SwkY5v55D8Yk6mVTWl7RHf+DAEcPw/kytJvwovM3 Oj5UI3HpBhB2AYh7dHj8A5pK/cdmZoCGiDvGDmI0PImQkWz358MrR09U7i3mwA+1T9Xq 5cJg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=0U3DN21jJSHjryo32FyL3BVOe7dtJ75E6Tjlu2mOfww=; b=ofP0KcW4O9uE+CYv2R7jfmmxurlIkioGlimgwmF6GOuVoaIWsnMwikveMyF6sva/fl a99IPcQR/a9vhz5Qy9Ja0yRxBxueTQu8kk77hHJa9V8vzqq8QvS8eX8n/8MWYeVYtrcH /mwphXo9y1DjMnnRWaCUa/w7TEJZFeb3nTmU1zYXH8qFfRkGvBNBdsMAx1/sfpHxhuKp ojGuFWIJ+Crm5yr8GMVVp3SOJhYEb5nqefMxmBfmE0tDPkQEB5QQIfsoqvOlIQZbCnG0 gh1m5twT+nBmdjo4vp+0fqfMXtz9HytyUrFHxUq/tn0uefRinzsQ7dP2pSn0HFk1WwxP piUA== X-Gm-Message-State: APjAAAWQLmTxtrvDxXyBpT/s/6Nv2k9M1j6dgeLUgutbe0LLpzRhW/B3 bJxqxGPb9fOI5oAjsYZRYvA= X-Google-Smtp-Source: APXvYqzi00q2dqHNPbmod0vP3ihHgKlboHkHO/woa6rLQB6YgrpOuAj2RovkltDSUbDAaep9sWFp1Q== X-Received: by 2002:a17:902:525:: with SMTP id 34mr40408528plf.138.1556206418963; Thu, 25 Apr 2019 08:33:38 -0700 (PDT) Received: from localhost.localdomain ([104.238.181.70]) by smtp.gmail.com with ESMTPSA id c14sm2643363pgj.94.2019.04.25.08.33.33 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 25 Apr 2019 08:33:38 -0700 (PDT) From: Changbin Du To: rjw@rjwysocki.net, Jonathan Corbet Cc: Bjorn Helgaas , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, fenghua.yu@intel.com, linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org, linux-gpio@vger.kernel.org, mchehab+samsung@kernel.org, Changbin Du Subject: [PATCH v6 21/24] Documentation: ACPI: move cppc_sysfs.txt to admin-guide/acpi and convert to reST Date: Thu, 25 Apr 2019 23:31:14 +0800 Message-Id: <20190425153117.16057-22-changbin.du@gmail.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190425153117.16057-1-changbin.du@gmail.com> References: <20190425153117.16057-1-changbin.du@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This converts the plain text documentation to reStructuredText format and add it to Sphinx TOC tree. No essential content change. Signed-off-by: Changbin Du --- .../acpi/cppc_sysfs.rst} | 71 ++++++++++--------- Documentation/admin-guide/acpi/index.rst | 1 + 2 files changed, 40 insertions(+), 32 deletions(-) rename Documentation/{acpi/cppc_sysfs.txt => admin-guide/acpi/cppc_sysfs.rst} (51%) diff --git a/Documentation/acpi/cppc_sysfs.txt b/Documentation/admin-guide/acpi/cppc_sysfs.rst similarity index 51% rename from Documentation/acpi/cppc_sysfs.txt rename to Documentation/admin-guide/acpi/cppc_sysfs.rst index f20fb445135d..a4b99afbe331 100644 --- a/Documentation/acpi/cppc_sysfs.txt +++ b/Documentation/admin-guide/acpi/cppc_sysfs.rst @@ -1,5 +1,11 @@ +.. SPDX-License-Identifier: GPL-2.0 - Collaborative Processor Performance Control (CPPC) +================================================== +Collaborative Processor Performance Control (CPPC) +================================================== + +CPPC +==== CPPC defined in the ACPI spec describes a mechanism for the OS to manage the performance of a logical processor on a contigious and abstract performance @@ -10,31 +16,28 @@ For more details on CPPC please refer to the ACPI specification at: http://uefi.org/specifications -Some of the CPPC registers are exposed via sysfs under: - -/sys/devices/system/cpu/cpuX/acpi_cppc/ - -for each cpu X +Some of the CPPC registers are exposed via sysfs under:: --------------------------------------------------------------------------------- + /sys/devices/system/cpu/cpuX/acpi_cppc/ -$ ls -lR /sys/devices/system/cpu/cpu0/acpi_cppc/ -/sys/devices/system/cpu/cpu0/acpi_cppc/: -total 0 --r--r--r-- 1 root root 65536 Mar 5 19:38 feedback_ctrs --r--r--r-- 1 root root 65536 Mar 5 19:38 highest_perf --r--r--r-- 1 root root 65536 Mar 5 19:38 lowest_freq --r--r--r-- 1 root root 65536 Mar 5 19:38 lowest_nonlinear_perf --r--r--r-- 1 root root 65536 Mar 5 19:38 lowest_perf --r--r--r-- 1 root root 65536 Mar 5 19:38 nominal_freq --r--r--r-- 1 root root 65536 Mar 5 19:38 nominal_perf --r--r--r-- 1 root root 65536 Mar 5 19:38 reference_perf --r--r--r-- 1 root root 65536 Mar 5 19:38 wraparound_time +for each cpu X:: --------------------------------------------------------------------------------- + $ ls -lR /sys/devices/system/cpu/cpu0/acpi_cppc/ + /sys/devices/system/cpu/cpu0/acpi_cppc/: + total 0 + -r--r--r-- 1 root root 65536 Mar 5 19:38 feedback_ctrs + -r--r--r-- 1 root root 65536 Mar 5 19:38 highest_perf + -r--r--r-- 1 root root 65536 Mar 5 19:38 lowest_freq + -r--r--r-- 1 root root 65536 Mar 5 19:38 lowest_nonlinear_perf + -r--r--r-- 1 root root 65536 Mar 5 19:38 lowest_perf + -r--r--r-- 1 root root 65536 Mar 5 19:38 nominal_freq + -r--r--r-- 1 root root 65536 Mar 5 19:38 nominal_perf + -r--r--r-- 1 root root 65536 Mar 5 19:38 reference_perf + -r--r--r-- 1 root root 65536 Mar 5 19:38 wraparound_time * highest_perf : Highest performance of this processor (abstract scale). -* nominal_perf : Highest sustained performance of this processor (abstract scale). +* nominal_perf : Highest sustained performance of this processor + (abstract scale). * lowest_nonlinear_perf : Lowest performance of this processor with nonlinear power savings (abstract scale). * lowest_perf : Lowest performance of this processor (abstract scale). @@ -48,22 +51,26 @@ total 0 * feedback_ctrs : Includes both Reference and delivered performance counter. Reference counter ticks up proportional to processor's reference performance. Delivered counter ticks up proportional to processor's delivered performance. -* wraparound_time: Minimum time for the feedback counters to wraparound (seconds). +* wraparound_time: Minimum time for the feedback counters to wraparound + (seconds). * reference_perf : Performance level at which reference performance counter accumulates (abstract scale). --------------------------------------------------------------------------------- - Computing Average Delivered Performance +Computing Average Delivered Performance +======================================= + +Below describes the steps to compute the average performance delivered by +taking two different snapshots of feedback counters at time T1 and T2. + + T1: Read feedback_ctrs as fbc_t1 + Wait or run some workload -Below describes the steps to compute the average performance delivered by taking -two different snapshots of feedback counters at time T1 and T2. + T2: Read feedback_ctrs as fbc_t2 -T1: Read feedback_ctrs as fbc_t1 - Wait or run some workload -T2: Read feedback_ctrs as fbc_t2 +:: -delivered_counter_delta = fbc_t2[del] - fbc_t1[del] -reference_counter_delta = fbc_t2[ref] - fbc_t1[ref] + delivered_counter_delta = fbc_t2[del] - fbc_t1[del] + reference_counter_delta = fbc_t2[ref] - fbc_t1[ref] -delivered_perf = (refernce_perf x delivered_counter_delta) / reference_counter_delta + delivered_perf = (refernce_perf x delivered_counter_delta) / reference_counter_delta diff --git a/Documentation/admin-guide/acpi/index.rst b/Documentation/admin-guide/acpi/index.rst index d68e9914c5ff..9049a7b9f065 100644 --- a/Documentation/admin-guide/acpi/index.rst +++ b/Documentation/admin-guide/acpi/index.rst @@ -10,3 +10,4 @@ the Linux ACPI support. initrd_table_override dsdt-override + cppc_sysfs -- 2.20.1