CPU Idle - 2020.2 English

Example 1

The following code example is the sysfs interface for cpuidle.

$ ls -lR /sys/devices/system/cpu/cpu0/cpuidle/
/sys/devices/system/cpu/cpu0/cpuidle/:
drwxr-xr-x 2 root root 0 Jun 10 21:55 state0
drwxr-xr-x 2 root root 0 Jun 10 21:55 state1
/sys/devices/system/cpu/cpu0/cpuidle/state0:
-r--r--r-- 1 root root 4096 Jun 10 21:55 desc
-rw-r--r-- 1 root root 4096 Jun 10 21:55 disable
-r--r--r-- 1 root root 4096 Jun 10 21:55 latency
-r--r--r-- 1 root root 4096 Jun 10 21:55 name
-r--r--r-- 1 root root 4096 Jun 10 21:55 power
-r--r--r-- 1 root root 4096 Jun 10 21:55 residency
-r--r--r-- 1 root root 4096 Jun 10 21:55 time
-r--r--r-- 1 root root 4096 Jun 10 21:55 usage
/sys/devices/system/cpu/cpu0/cpuidle/state1:
-r--r--r-- 1 root root 4096 Jun 10 21:55 desc
-rw-r--r-- 1 root root 4096 Jun 10 21:55 disable
-r--r--r-- 1 root root 4096 Jun 10 21:55 latency
-r--r--r-- 1 root root 4096 Jun 10 21:55 name
-r--r--r-- 1 root root 4096 Jun 10 21:55 power
-r--r--r-- 1 root root 4096 Jun 10 21:55 residency
-r--r--r-- 1 root root 4096 Jun 10 21:55 time
-r--r--r-- 1 root root 4096 Jun 10 21:55 usage

where:

desc

Small description about the idle state (string)

disable

Option to disable this idle state (bool)

latency

Latency to exit out of this idle state (in microseconds)

name

Name of the idle state (string)

power

Power consumed while in this idle state (in milliwatts)

time

Total time spent in this idle state (in microseconds)

usage

Number of times this state was entered (count)

Example 2

The following code example is the sysfs interface for cpuidle governors.

$ ls -lR /sys/devices/system/cpu/cpuidle/
/sys/devices/system/cpu/cpuidle/:
-r--r--r-- 1 root root 4096 Jun 10 21:55 current_driver
-r--r--r-- 1 root root 4096 Jun 10 21:55 current_governor_ro */

For more information, refer to the following resources:

• https://www.kernel.org/doc/Documentation/cpuidle/core.txt
• https://www.kernel.org/doc/Documentation/cpuidle/driver.txt
• https://www.kernel.org/doc/Documentation/cpuidle/governor.txt
• https://www.kernel.org/doc/Documentation/cpuidle/sysfs.txt