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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
   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)



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