7043a9f77c
The 'cpupower-set' tool has been enhanced with new features: commitf2ab555711("cpupower: Add EPP value change support") commitdf8776b036("cpupower: Add support for amd_pstate mode change") commiteb426fc6bd("cpupower: Add turbo-boost support in cpupower") However, the corresponding manpage was never updated. Add a basic description of these new options to the existing manpage. Commit description updated to fix checkpatch errors: Shuah Khan Signed-off-by: Tor Vic <torvic9@mailbox.org> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
100 lines
3.1 KiB
Groff
100 lines
3.1 KiB
Groff
.TH CPUPOWER\-SET "1" "22/02/2011" "" "cpupower Manual"
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.SH NAME
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cpupower\-set \- Set processor power related kernel or hardware configurations
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.SH SYNOPSIS
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.ft B
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.B cpupower set [ \-b VAL | \-e POLICY | \-m MODE | \-t BOOL ]
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.SH DESCRIPTION
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\fBcpupower set \fP sets kernel configurations or directly accesses hardware
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registers affecting processor power saving policies.
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Some options are platform wide, some affect single cores. By default values
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are applied on all cores. How to modify single core configurations is
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described in the cpupower(1) manpage in the \-\-cpu option section. Whether an
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option affects the whole system or can be applied to individual cores is
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described in the Options sections.
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Use \fBcpupower info \fP to read out current settings and whether they are
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supported on the system at all.
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.SH OPTIONS
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.PP
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\-\-perf-bias, \-b
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.RS 4
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Sets a register on supported Intel processore which allows software to convey
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its policy for the relative importance of performance versus energy savings to
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the processor.
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The range of valid numbers is 0-15, where 0 is maximum
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performance and 15 is maximum energy efficiency.
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The processor uses this information in model-specific ways
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when it must select trade-offs between performance and
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energy efficiency.
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This policy hint does not supersede Processor Performance states
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(P-states) or CPU Idle power states (C-states), but allows
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software to have influence where it would otherwise be unable
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to express a preference.
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For example, this setting may tell the hardware how
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aggressively or conservatively to control frequency
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in the "turbo range" above the explicitly OS-controlled
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P-state frequency range. It may also tell the hardware
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how aggressively it should enter the OS requested C-states.
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This option can be applied to individual cores only via the \-\-cpu option,
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cpupower(1).
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Setting the performance bias value on one CPU can modify the setting on
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related CPUs as well (for example all CPUs on one socket), because of
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hardware restrictions.
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Use \fBcpupower -c all info -b\fP to verify.
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This options needs the msr kernel driver (CONFIG_X86_MSR) loaded.
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.RE
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.PP
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\-\-epp, \-e
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.RS 4
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Sets the energy performance policy preference on supported Intel or AMD
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processors which use the Intel or AMD P-State cpufreq driver respectively.
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Available policies can be found with
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\fBcat /sys/devices/system/cpu/cpufreq/policy0/energy_performance_available_preferences\fP :
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.RS 4
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default performance balance_performance balance_power power
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.RE
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.RE
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.PP
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\-\-amd\-pstate\-mode, \-m
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.RS 4
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Sets the AMD P-State mode for supported AMD processors.
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Available modes are "active", "guided" or "passive".
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Refer to the AMD P-State kernel documentation for further information.
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.RE
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.PP
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\-\-turbo\-boost, \-t
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.RS 4
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This option is used to enable or disable the turbo boost feature on
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supported Intel and AMD processors.
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This option takes as parameter either \fB1\fP to enable, or \fB0\fP to disable the feature.
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.RE
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.SH "SEE ALSO"
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cpupower-info(1), cpupower-monitor(1), powertop(1)
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.PP
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.SH AUTHORS
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.nf
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\-\-perf\-bias parts written by Len Brown <len.brown@intel.com>
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Thomas Renninger <trenn@suse.de>
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