| .TH "CPUPOWER-IDLE-SET" "1" "0.1" "" "cpupower Manual" |
| .SH "NAME" |
| .LP |
| cpupower idle\-set \- Utility to set cpu idle state specific kernel options |
| .SH "SYNTAX" |
| .LP |
| cpupower [ \-c cpulist ] idle\-info [\fIoptions\fP] |
| .SH "DESCRIPTION" |
| .LP |
| The cpupower idle\-set subcommand allows to set cpu idle, also called cpu |
| sleep state, specific options offered by the kernel. One example is disabling |
| sleep states. This can be handy for power vs performance tuning. |
| .SH "OPTIONS" |
| .LP |
| .TP |
| \fB\-d\fR \fB\-\-disable\fR <STATE_NO> |
| Disable a specific processor sleep state. |
| .TP |
| \fB\-e\fR \fB\-\-enable\fR <STATE_NO> |
| Enable a specific processor sleep state. |
| .TP |
| \fB\-D\fR \fB\-\-disable-by-latency\fR <LATENCY> |
| Disable all idle states with a equal or higher latency than <LATENCY> |
| .TP |
| \fB\-E\fR \fB\-\-enable-all\fR |
| Enable all idle states if not enabled already. |
| |
| .SH "REMARKS" |
| .LP |
| Cpuidle Governors Policy on Disabling Sleep States |
| |
| .RS 4 |
| Depending on the used cpuidle governor, implementing the kernel policy |
| how to choose sleep states, subsequent sleep states on this core, might get |
| disabled as well. |
| |
| There are two cpuidle governors ladder and menu. While the ladder |
| governor is always available, if CONFIG_CPU_IDLE is selected, the |
| menu governor additionally requires CONFIG_NO_HZ. |
| |
| The behavior and the effect of the disable variable depends on the |
| implementation of a particular governor. In the ladder governor, for |
| example, it is not coherent, i.e. if one is disabling a light state, |
| then all deeper states are disabled as well. Likewise, if one enables a |
| deep state but a lighter state still is disabled, then this has no effect. |
| .RE |
| .LP |
| Disabling the Lightest Sleep State may not have any Affect |
| |
| .RS 4 |
| If criteria are not met to enter deeper sleep states and the lightest sleep |
| state is chosen when idle, the kernel may still enter this sleep state, |
| irrespective of whether it is disabled or not. This is also reflected in |
| the usage count of the disabled sleep state when using the cpupower idle-info |
| command. |
| .RE |
| .LP |
| Selecting specific CPU Cores |
| |
| .RS 4 |
| By default processor sleep states of all CPU cores are set. Please refer |
| to the cpupower(1) manpage in the \-\-cpu option section how to disable |
| C-states of specific cores. |
| .RE |
| .SH "FILES" |
| .nf |
| \fI/sys/devices/system/cpu/cpu*/cpuidle/state*\fP |
| \fI/sys/devices/system/cpu/cpuidle/*\fP |
| .fi |
| .SH "AUTHORS" |
| .nf |
| Thomas Renninger <trenn@suse.de> |
| .fi |
| .SH "SEE ALSO" |
| .LP |
| cpupower(1), cpupower\-monitor(1), cpupower\-info(1), cpupower\-set(1), |
| cpupower\-idle\-info(1) |
