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→Q: How can I limit the number of active CPU cores?
For further details, please refer to the linux-am33x/Documentation/kernel-parameters.txt file of the kernel source tree provided with the XELK.
=== Q: How can I change the CPU clock frequency? ===
'''A''': The frequency of the CPU can be changed on the run using the Cpufreq framework (please refer to the documentation included into the Documentation/cpu-freq directory of the kernel source tree). The cpufreq framework works in conjunction with the related driver & governor.
Cpufreq implementation controls the Linux OPP (Operating Performance Points) adjusting the CPU core voltages and frequencies. CPUFreq is enabled by default in the AXEL kernel configuration.
To view the available governors:
<pre class="board-terminal">
root@axel-lite:~# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors
interactive conservative ondemand userspace powersave performance
</pre>
To view the supported OPP's (frequency in KHz):
<pre class="board-terminal">
root@axel-lite:~# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
396000 792000 996000
</pre>
To change the OPP:
<pre class="board-terminal">
root@axel-lite:~# echo 396000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed
</pre>
Please note that OPP can be changed only using the '''userspace''' governor. If governors like ondemand is used, OPP change happens automatically based on the system load.
