CPUPOWER-IDLE-SET(1) cpupower Manual CPUPOWER-IDLE-SET(1)
NAME
cpupower idle-set - Utility to set cpu idle state specific kernel
options
SYNTAX
cpupower [ -c cpulist ] idle-info [options]
DESCRIPTION
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 tun-
ing.
OPTIONS
-d --disable <STATE_NO>
Disable a specific processor sleep state.
-e --enable <STATE_NO>
Enable a specific processor sleep state.
-D --disable-by-latency <LATENCY>
Disable all idle states with a equal or higher latency than
<LATENCY>.
Enable all idle states with a latency lower than <LATENCY>.
-E --enable-all
Enable all idle states if not enabled already.
REMARKS
Cpuidle Governors Policy on Disabling Sleep States
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.
Disabling the Lightest Sleep State may not have any Affect
If criteria are not met to enter deeper sleep states and the light-
est 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.
Selecting specific CPU Cores
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.
FILES
/sys/devices/system/cpu/cpu*/cpuidle/state*
/sys/devices/system/cpu/cpuidle/*
AUTHORS
Thomas Renninger <trenn AT suse.de>
SEE ALSO
cpupower(1), cpupower-monitor(1), cpupower-info(1), cpupower-set(1),
cpupower-idle-info(1)
0.1 CPUPOWER-IDLE-SET(1)