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author | Ingo Molnar <mingo@kernel.org> | 2013-12-17 15:22:35 +0100 |
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committer | Ingo Molnar <mingo@kernel.org> | 2013-12-17 15:22:35 +0100 |
commit | ffe732c2430c55074bebb172d33d909c662cd0e3 (patch) | |
tree | d39087d7b5d8caa505b23b6ea2abc2e33efa5be5 /tools/power/cpupower/man/cpupower-idle-set.1 | |
parent | 40ea2b42d7c44386cf81d5636d574193da2c8df2 (diff) | |
parent | 757dfcaa41844595964f1220f1d33182dae49976 (diff) | |
download | blackbird-op-linux-ffe732c2430c55074bebb172d33d909c662cd0e3.tar.gz blackbird-op-linux-ffe732c2430c55074bebb172d33d909c662cd0e3.zip |
Merge branch 'sched/urgent' into sched/core
Merge the latest batch of fixes before applying development patches.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'tools/power/cpupower/man/cpupower-idle-set.1')
-rw-r--r-- | tools/power/cpupower/man/cpupower-idle-set.1 | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/tools/power/cpupower/man/cpupower-idle-set.1 b/tools/power/cpupower/man/cpupower-idle-set.1 new file mode 100644 index 000000000000..6b1607272a5b --- /dev/null +++ b/tools/power/cpupower/man/cpupower-idle-set.1 @@ -0,0 +1,71 @@ +.TH "CPUPOWER-IDLE-SET" "1" "0.1" "" "cpupower Manual" +.SH "NAME" +.LP +cpupower idle\-set \- Utility to set cpu idle state specific kernel options +.SH "SYNTAX" +.LP +cpupower [ \-c cpulist ] idle\-info [\fIoptions\fP] +.SH "DESCRIPTION" +.LP +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. +.SH "OPTIONS" +.LP +.TP +\fB\-d\fR \fB\-\-disable\fR +Disable a specific processor sleep state. +.TP +\fB\-e\fR \fB\-\-enable\fR +Enable a specific processor sleep state. + +.SH "REMARKS" +.LP +Cpuidle Governors Policy on Disabling Sleep States + +.RS 4 +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. +.RE +.LP +Disabling the Lightest Sleep State may not have any Affect + +.RS 4 +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. +.RE +.LP +Selecting specific CPU Cores + +.RS 4 +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. +.RE +.SH "FILES" +.nf +\fI/sys/devices/system/cpu/cpu*/cpuidle/state*\fP +\fI/sys/devices/system/cpu/cpuidle/*\fP +.fi +.SH "AUTHORS" +.nf +Thomas Renninger <trenn@suse.de> +.fi +.SH "SEE ALSO" +.LP +cpupower(1), cpupower\-monitor(1), cpupower\-info(1), cpupower\-set(1), +cpupower\-idle\-info(1) |