From: Changbin Du <changbin.du@gmail.com>
To: rjw@rjwysocki.net, Jonathan Corbet <corbet@lwn.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>,
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 <changbin.du@gmail.com>
Subject: [PATCH v5 20/23] Documentation: ACPI: move cppc_sysfs.txt to admin-guide/acpi and convert to reST
Date: Thu, 25 Apr 2019 01:53:03 +0800 [thread overview]
Message-ID: <20190424175306.25880-21-changbin.du@gmail.com> (raw)
In-Reply-To: <20190424175306.25880-1-changbin.du@gmail.com>
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 <changbin.du@gmail.com>
---
.../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
next prev parent reply other threads:[~2019-04-24 17:53 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-24 17:52 [PATCH v5 00/23] Include linux ACPI docs into Sphinx TOC tree Changbin Du
2019-04-24 17:52 ` [PATCH v5 01/23] Documentation: ACPI: move namespace.txt to firmware-guide/acpi and convert to reST Changbin Du
2019-04-24 17:52 ` [PATCH v5 02/23] Documentation: ACPI: move enumeration.txt " Changbin Du
2019-04-24 17:52 ` [PATCH v5 03/23] Documentation: ACPI: move osi.txt " Changbin Du
2019-04-24 17:52 ` [PATCH v5 04/23] Documentation: ACPI: move linuxized-acpica.txt to driver-api/acpi " Changbin Du
2019-04-24 17:52 ` [PATCH v5 05/23] Documentation: ACPI: move scan_handlers.txt " Changbin Du
2019-04-24 17:52 ` [PATCH v5 06/23] Documentation: ACPI: move DSD-properties-rules.txt to firmware-guide/acpi and covert " Changbin Du
2019-04-24 17:52 ` [PATCH v5 07/23] Documentation: ACPI: move gpio-properties.txt to firmware-guide/acpi and convert " Changbin Du
2019-04-24 17:52 ` [PATCH v5 08/23] Documentation: ACPI: move method-customizing.txt " Changbin Du
2019-04-24 18:08 ` Mauro Carvalho Chehab
2019-04-24 17:52 ` [PATCH v5 09/23] Documentation: ACPI: move initrd_table_override.txt to admin-guide/acpi " Changbin Du
2019-04-24 17:52 ` [PATCH v5 10/23] Documentation: ACPI: move dsdt-override.txt " Changbin Du
2019-04-24 17:52 ` [PATCH v5 11/23] Documentation: ACPI: move i2c-muxes.txt to firmware-guide/acpi " Changbin Du
2019-04-24 17:52 ` [PATCH v5 12/23] Documentation: ACPI: move acpi-lid.txt " Changbin Du
2019-04-24 17:52 ` [PATCH v5 13/23] Documentation: ACPI: move dsd/graph.txt " Changbin Du
2019-04-24 17:52 ` [PATCH v5 14/23] Documentation: ACPI: move dsd/data-node-references.txt " Changbin Du
2019-04-24 18:10 ` Mauro Carvalho Chehab
2019-04-24 17:52 ` [PATCH v5 15/23] Documentation: ACPI: move debug.txt " Changbin Du
2019-04-24 17:52 ` [PATCH v5 16/23] Documentation: ACPI: move method-tracing.txt to firmware-guide/acpi and convert to rsST Changbin Du
2019-04-24 17:53 ` [PATCH v5 17/23] Documentation: ACPI: move aml-debugger.txt to firmware-guide/acpi and convert to reST Changbin Du
2019-04-24 17:53 ` [PATCH v5 18/23] Documentation: ACPI: move apei/output_format.txt " Changbin Du
2019-04-24 17:53 ` [PATCH v5 19/23] Documentation: ACPI: move apei/einj.txt " Changbin Du
2019-04-24 17:53 ` Changbin Du [this message]
2019-04-24 18:12 ` [PATCH v5 20/23] Documentation: ACPI: move cppc_sysfs.txt to admin-guide/acpi " Mauro Carvalho Chehab
2019-04-25 0:44 ` Changbin Du
2019-04-24 17:53 ` [PATCH v5 21/23] Documentation: ACPI: move lpit.txt to firmware-guide/acpi " Changbin Du
2019-04-24 17:53 ` [PATCH v5 22/23] Documentation: ACPI: move ssdt-overlays.txt to admin-guide/acpi " Changbin Du
2019-04-24 17:53 ` [PATCH v5 23/23] Documentation: ACPI: move video_extension.txt to firmware-guide/acpi " Changbin Du
2019-04-24 18:26 ` Mauro Carvalho Chehab
2019-04-25 8:44 ` [PATCH v5 00/23] Include linux ACPI docs into Sphinx TOC tree Rafael J. Wysocki
2019-04-25 15:20 ` Changbin Du
2019-05-01 10:15 ` Rafael J. Wysocki
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