NAME

       cpupower-idle-set - Utility to set cpu idle state specific kernel options

SYNTAX

       cpupower [ -c cpulist ] idle-set [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)