66 строки
2.2 KiB
Groff
66 строки
2.2 KiB
Groff
.TH CPUPOWER\-SET "1" "22/02/2011" "" "cpupower Manual"
|
|
.SH NAME
|
|
cpupower\-set \- Set processor power related kernel or hardware configurations
|
|
.SH SYNOPSIS
|
|
.ft B
|
|
.B cpupower set [ \-b VAL ]
|
|
|
|
|
|
.SH DESCRIPTION
|
|
\fBcpupower set \fP sets kernel configurations or directly accesses hardware
|
|
registers affecting processor power saving policies.
|
|
|
|
Some options are platform wide, some affect single cores. By default values
|
|
are applied on all cores. How to modify single core configurations is
|
|
described in the cpupower(1) manpage in the \-\-cpu option section. Whether an
|
|
option affects the whole system or can be applied to individual cores is
|
|
described in the Options sections.
|
|
|
|
Use \fBcpupower info \fP to read out current settings and whether they are
|
|
supported on the system at all.
|
|
|
|
.SH Options
|
|
.PP
|
|
\-\-perf-bias, \-b
|
|
.RS 4
|
|
Sets a register on supported Intel processore which allows software to convey
|
|
its policy for the relative importance of performance versus energy savings to
|
|
the processor.
|
|
|
|
The range of valid numbers is 0-15, where 0 is maximum
|
|
performance and 15 is maximum energy efficiency.
|
|
|
|
The processor uses this information in model-specific ways
|
|
when it must select trade-offs between performance and
|
|
energy efficiency.
|
|
|
|
This policy hint does not supersede Processor Performance states
|
|
(P-states) or CPU Idle power states (C-states), but allows
|
|
software to have influence where it would otherwise be unable
|
|
to express a preference.
|
|
|
|
For example, this setting may tell the hardware how
|
|
aggressively or conservatively to control frequency
|
|
in the "turbo range" above the explicitly OS-controlled
|
|
P-state frequency range. It may also tell the hardware
|
|
how aggressively it should enter the OS requested C-states.
|
|
|
|
This option can be applied to individual cores only via the \-\-cpu option,
|
|
cpupower(1).
|
|
|
|
Setting the performance bias value on one CPU can modify the setting on
|
|
related CPUs as well (for example all CPUs on one socket), because of
|
|
hardware restrictions.
|
|
Use \fBcpupower -c all info -b\fP to verify.
|
|
|
|
This options needs the msr kernel driver (CONFIG_X86_MSR) loaded.
|
|
.RE
|
|
|
|
.SH "SEE ALSO"
|
|
cpupower-info(1), cpupower-monitor(1), powertop(1)
|
|
.PP
|
|
.SH AUTHORS
|
|
.nf
|
|
\-\-perf\-bias parts written by Len Brown <len.brown@intel.com>
|
|
Thomas Renninger <trenn@suse.de>
|