cpu_freq_throttle is a CPU throttle and frequency
controller. It uses files in
/sys/devices/system/cpu/cpu0/cpufreq/ to set or
throttle the CPU speed. It requires the
acpi-cpufreq Linux kernel module to be loaded and
requires "governor" to be in userspace mode. If it
is not in userspace mode, cpu_freq_throttle will
change it.