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
       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 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 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                                  CPUPOWER-IDLE-SET(1)