set CPU frequency in Linux

• ls /sys/devices/system/cpu/cpu0/
• cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_driver etc.

scaling_available_governors: ondemand userspace performance
scaling_available_frequencies

• modprobe acpi-cpufreq
• cat /proc/cpuinfo | grep 'cpu MHz'
• cpufreq-selector
  -c, --cpu CPU Number
  -g, --governor Governor
  -f, --frequency Frequency in KHz
  
• /usr/sbin/cpuspeed -m 2000000 -M 2000000 -s 7

/etc/sysconfig/cpuspeed, configuration file
/etc/init.d/cpuspeed, initialzation script
/usr/sbin/cpuspeed, cpuspeed program

• cpufreq-set

cpufreq-set -d 2667000 -u 2667000 -c 0

• cpufreq-info