4.4. CPU Frequency Governors
cpufreqgovernors determine the frequency of a CPU at any given time based on a set of rules about the kind of behavior that prompts a change to a higher or lower frequency.
cpufreq_ondemandgovernor for most situations, as this governor provides better performance through a higher CPU frequency when the system is under load, and power savings through a lower CPU frequency when the system is not being heavily used.
io_is_busy. If this is set to
1, Input/Output (I/O) activity is included in CPU activity calculations, and if set to
0it is excluded. The default setting is
1. If I/O activity is excluded, the
ondemandgovernor may reduce the CPU frequency to reduce power usage, resulting in slower I/O operations.
cpufreq_performancegovernor. This governor uses the highest possible CPU frequency to ensure that tasks execute as quickly as possible. This governor does not make use of power saving mechanisms such as sleep or idle, and is therefore not recommended for data centers or similar large deployments.
Procedure 4.1. Enabling and configuring a governor
- Ensure that cpupowerutils is installed:
# yum install cpupowerutils
- Check that the driver you want to use is available.
# cpupower frequency-info --governors
- If the driver you want is not available, use the
modprobecommand to add it to your system. For example, to add the
# modprobe cpufreq_ondemand
- Set the governor temporarily by using the cpupower command line tool. For example, to set the
# cpupower frequency-set --governor ondemand