Linux Kernel in a Nutshell

Name

CPU_FREQ — CPU frequency scaling

CPU frequency scaling allows you to change the clock speed of CPUs on the fly. This can save power, because the lower the CPU clock speed, the less power the CPU consumes.

Note that this driver doesn't automatically change the CPU clock speed; you need to either enable a dynamic CPUFreq policy governor (described later) after booting or use a userspace tool.

For details, take a look at Documentation/cpu-freq.