From aadfa206e9bb6fcee0b9fcd2fc39804026cdefcc Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Tue, 3 Mar 2020 14:52:06 +0100 Subject: docs: cpu-freq: convert cpufreq-stats.txt to ReST - Add a SPDX header; - Add a document title, based on the original contents of cpu-freq/index.txt; - Use lists where needed; - Comment out the existing text-only index; - Adjust some title marks; - Use bold on some places; - Mark literal blocks as such; - Some whitespace fixes and new line breaks; - Add it to cpu-freq/index.rst. Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Rafael J. Wysocki --- Documentation/cpu-freq/cpufreq-stats.rst | 136 +++++++++++++++++++++++++++++++ Documentation/cpu-freq/cpufreq-stats.txt | 127 ----------------------------- Documentation/cpu-freq/index.rst | 1 + 3 files changed, 137 insertions(+), 127 deletions(-) create mode 100644 Documentation/cpu-freq/cpufreq-stats.rst delete mode 100644 Documentation/cpu-freq/cpufreq-stats.txt (limited to 'Documentation') diff --git a/Documentation/cpu-freq/cpufreq-stats.rst b/Documentation/cpu-freq/cpufreq-stats.rst new file mode 100644 index 000000000000..9ad695b1c7db --- /dev/null +++ b/Documentation/cpu-freq/cpufreq-stats.rst @@ -0,0 +1,136 @@ +.. SPDX-License-Identifier: GPL-2.0 + +========================================== +General Description of sysfs CPUFreq Stats +========================================== + +information for users + + +Author: Venkatesh Pallipadi + +.. Contents + + 1. Introduction + 2. Statistics Provided (with example) + 3. Configuring cpufreq-stats + + +1. Introduction +=============== + +cpufreq-stats is a driver that provides CPU frequency statistics for each CPU. +These statistics are provided in /sysfs as a bunch of read_only interfaces. This +interface (when configured) will appear in a separate directory under cpufreq +in /sysfs (/devices/system/cpu/cpuX/cpufreq/stats/) for each CPU. +Various statistics will form read_only files under this directory. + +This driver is designed to be independent of any particular cpufreq_driver +that may be running on your CPU. So, it will work with any cpufreq_driver. + + +2. Statistics Provided (with example) +===================================== + +cpufreq stats provides following statistics (explained in detail below). + +- time_in_state +- total_trans +- trans_table + +All the statistics will be from the time the stats driver has been inserted +(or the time the stats were reset) to the time when a read of a particular +statistic is done. Obviously, stats driver will not have any information +about the frequency transitions before the stats driver insertion. + +:: + + :/sys/devices/system/cpu/cpu0/cpufreq/stats # ls -l + total 0 + drwxr-xr-x 2 root root 0 May 14 16:06 . + drwxr-xr-x 3 root root 0 May 14 15:58 .. + --w------- 1 root root 4096 May 14 16:06 reset + -r--r--r-- 1 root root 4096 May 14 16:06 time_in_state + -r--r--r-- 1 root root 4096 May 14 16:06 total_trans + -r--r--r-- 1 root root 4096 May 14 16:06 trans_table + +- **reset** + +Write-only attribute that can be used to reset the stat counters. This can be +useful for evaluating system behaviour under different governors without the +need for a reboot. + +- **time_in_state** + +This gives the amount of time spent in each of the frequencies supported by +this CPU. The cat output will have "