- Table of contents
- Setting SOM Clock Speed
Setting SOM Clock Speed¶
Objective¶
The AM62x Cortex A-53 processor complex can run at different frequencies. This provides a way to balance between performance and consumption of power and generation of heat.
The goal of this wiki page is to:
- List which core frequencies can be changed.
- Demonstrate how to view the current core frequencies.
- How to access the CPU governors to scale the CPU frequencies depending on the system load.
CPU Frequencies¶
The CPUs are configured with various governor options to scale the frequencies between 200 MHz to 1.4GHz depending on the system load and processor configuraiton. The settings for the frequencies / governors for the CPU complex can be found in the following directory:
/sys/devices/system/cpu/cpufreq/policy0
A list of available governors can be found by running the following:
root@mitysom-am62x:~# cat /sys/devices/system/cpu/cpufreq/policy0/scaling_available_governors ondemand userspace performance schedutil
Example below shows changing the CPU0 governor from ondemand to performance so that the CPU frequency will stay at the maximum allowed frequency.
root@mitysom-am62x:~# echo performance > /sys/devices/system/cpu/cpufreq/policy0/scaling_governor
A list of available CPU frequencies can be found by running the following:
root@mitysom-am57x:~# cat /sys/devices/system/cpu/cpufreq/policy0/scaling_available_frequencies 200000 400000 600000 800000 1000000 1250000 1400000
You can check the CPU frequency by running the following:
root@mitysom-am57x:~# cat /sys/devices/system/cpu/cpufreq/policy0/scaling_cur_freq 1400000
NOTE Remember to apply any changes to both CPUs (cpu0 or cpu1 / if applicable).
Conclusion¶
This wiki page has done the following:
- Demonstrated how to view the current CPU frequencies.
- Described how to access the CPU governors to scale the CPU frequencies depending on the system load.
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