cpupower-idle-set.1 2.5 KB

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  1. .TH "CPUPOWER-IDLE-SET" "1" "0.1" "" "cpupower Manual"
  2. .SH "NAME"
  3. .LP
  4. cpupower idle\-set \- Utility to set cpu idle state specific kernel options
  5. .SH "SYNTAX"
  6. .LP
  7. cpupower [ \-c cpulist ] idle\-info [\fIoptions\fP]
  8. .SH "DESCRIPTION"
  9. .LP
  10. The cpupower idle\-set subcommand allows to set cpu idle, also called cpu
  11. sleep state, specific options offered by the kernel. One example is disabling
  12. sleep states. This can be handy for power vs performance tuning.
  13. .SH "OPTIONS"
  14. .LP
  15. .TP
  16. \fB\-d\fR \fB\-\-disable\fR <STATE_NO>
  17. Disable a specific processor sleep state.
  18. .TP
  19. \fB\-e\fR \fB\-\-enable\fR <STATE_NO>
  20. Enable a specific processor sleep state.
  21. .TP
  22. \fB\-D\fR \fB\-\-disable-by-latency\fR <LATENCY>
  23. Disable all idle states with a equal or higher latency than <LATENCY>.
  24. Enable all idle states with a latency lower than <LATENCY>.
  25. .TP
  26. \fB\-E\fR \fB\-\-enable-all\fR
  27. Enable all idle states if not enabled already.
  28. .SH "REMARKS"
  29. .LP
  30. Cpuidle Governors Policy on Disabling Sleep States
  31. .RS 4
  32. Depending on the used cpuidle governor, implementing the kernel policy
  33. how to choose sleep states, subsequent sleep states on this core, might get
  34. disabled as well.
  35. There are two cpuidle governors ladder and menu. While the ladder
  36. governor is always available, if CONFIG_CPU_IDLE is selected, the
  37. menu governor additionally requires CONFIG_NO_HZ.
  38. The behavior and the effect of the disable variable depends on the
  39. implementation of a particular governor. In the ladder governor, for
  40. example, it is not coherent, i.e. if one is disabling a light state,
  41. then all deeper states are disabled as well. Likewise, if one enables a
  42. deep state but a lighter state still is disabled, then this has no effect.
  43. .RE
  44. .LP
  45. Disabling the Lightest Sleep State may not have any Affect
  46. .RS 4
  47. If criteria are not met to enter deeper sleep states and the lightest sleep
  48. state is chosen when idle, the kernel may still enter this sleep state,
  49. irrespective of whether it is disabled or not. This is also reflected in
  50. the usage count of the disabled sleep state when using the cpupower idle-info
  51. command.
  52. .RE
  53. .LP
  54. Selecting specific CPU Cores
  55. .RS 4
  56. By default processor sleep states of all CPU cores are set. Please refer
  57. to the cpupower(1) manpage in the \-\-cpu option section how to disable
  58. C-states of specific cores.
  59. .RE
  60. .SH "FILES"
  61. .nf
  62. \fI/sys/devices/system/cpu/cpu*/cpuidle/state*\fP
  63. \fI/sys/devices/system/cpu/cpuidle/*\fP
  64. .fi
  65. .SH "AUTHORS"
  66. .nf
  67. Thomas Renninger <trenn@suse.de>
  68. .fi
  69. .SH "SEE ALSO"
  70. .LP
  71. cpupower(1), cpupower\-monitor(1), cpupower\-info(1), cpupower\-set(1),
  72. cpupower\-idle\-info(1)