80 lines
2.5 KiB
Groff
80 lines
2.5 KiB
Groff
.TH "CPUPOWER-IDLE-SET" "1" "0.1" "" "cpupower Manual"
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.SH "NAME"
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.LP
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cpupower\-idle\-set \- Utility to set cpu idle state specific kernel options
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.SH "SYNTAX"
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.LP
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cpupower [ \-c cpulist ] idle\-info [\fIoptions\fP]
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.SH "DESCRIPTION"
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.LP
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The cpupower idle\-set subcommand allows to set cpu idle, also called cpu
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sleep state, specific options offered by the kernel. One example is disabling
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sleep states. This can be handy for power vs performance tuning.
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.SH "OPTIONS"
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.LP
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.TP
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\fB\-d\fR \fB\-\-disable\fR <STATE_NO>
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Disable a specific processor sleep state.
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.TP
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\fB\-e\fR \fB\-\-enable\fR <STATE_NO>
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Enable a specific processor sleep state.
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.TP
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\fB\-D\fR \fB\-\-disable-by-latency\fR <LATENCY>
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Disable all idle states with a equal or higher latency than <LATENCY>.
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Enable all idle states with a latency lower than <LATENCY>.
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.TP
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\fB\-E\fR \fB\-\-enable-all\fR
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Enable all idle states if not enabled already.
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.SH "REMARKS"
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.LP
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Cpuidle Governors Policy on Disabling Sleep States
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.RS 4
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Depending on the used cpuidle governor, implementing the kernel policy
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how to choose sleep states, subsequent sleep states on this core, might get
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disabled as well.
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There are two cpuidle governors ladder and menu. While the ladder
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governor is always available, if CONFIG_CPU_IDLE is selected, the
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menu governor additionally requires CONFIG_NO_HZ.
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The behavior and the effect of the disable variable depends on the
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implementation of a particular governor. In the ladder governor, for
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example, it is not coherent, i.e. if one is disabling a light state,
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then all deeper states are disabled as well. Likewise, if one enables a
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deep state but a lighter state still is disabled, then this has no effect.
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.RE
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.LP
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Disabling the Lightest Sleep State may not have any Affect
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.RS 4
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If criteria are not met to enter deeper sleep states and the lightest sleep
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state is chosen when idle, the kernel may still enter this sleep state,
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irrespective of whether it is disabled or not. This is also reflected in
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the usage count of the disabled sleep state when using the cpupower idle-info
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command.
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.RE
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.LP
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Selecting specific CPU Cores
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.RS 4
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By default processor sleep states of all CPU cores are set. Please refer
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to the cpupower(1) manpage in the \-\-cpu option section how to disable
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C-states of specific cores.
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.RE
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.SH "FILES"
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.nf
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\fI/sys/devices/system/cpu/cpu*/cpuidle/state*\fP
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\fI/sys/devices/system/cpu/cpuidle/*\fP
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.fi
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.SH "AUTHORS"
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.nf
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Thomas Renninger <trenn@suse.de>
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.fi
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.SH "SEE ALSO"
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.LP
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cpupower(1), cpupower\-monitor(1), cpupower\-info(1), cpupower\-set(1),
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cpupower\-idle\-info(1)
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