other versions
- jessie-backports 4.9.88-1+deb9u1~bpo8+1
- stretch 4.9.144-3
- testing 4.19.16-1
- stretch-backports 4.19.16-1~bpo9+1
- unstable 4.19.28-2
- experimental 5.0.2-1~exp1
CPUPOWER-IDLE-SET(1) | cpupower Manual | CPUPOWER-IDLE-SET(1) |
NAME¶
cpupower-idle-set - Utility to set cpu idle state specific kernel optionsSYNTAX¶
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 tuning.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 StatesDepending 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 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.
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@suse.de>
SEE ALSO¶
cpupower(1), cpupower-monitor(1), cpupower-info(1), cpupower-set(1), cpupower-idle-info(1)0.1 |