MAN page from CentOS 7 kernel-plus-tools-3.10.0-1160.21.1.el7.centos.plus.x86_64.rpm
Section: cpupower Manual (1)
cpupower-set - Set processor power related kernel or hardware configurations
SYNOPSIScpupower set [ -b VAL ]
sets kernel configurations or directly accesses hardwareregisters affecting processor power saving policies.
Some options are platform wide, some affect single cores. By default valuesare applied on all cores. How to modify single core configurations isdescribed in the cpupower(1) manpage in the --cpu option section. Whether anoption affects the whole system or can be applied to individual cores isdescribed in the Options sections.
Use cpupower info to read out current settings and whether they aresupported on the system at all.
- Sets a register on supported Intel processore which allows software to conveyits policy for the relative importance of performance versus energy savings tothe processor.
The range of valid numbers is 0-15, where 0 is maximumperformance and 15 is maximum energy efficiency.
The processor uses this information in model-specific wayswhen it must select trade-offs between performance andenergy efficiency.
This policy hint does not supersede Processor Performance states(P-states) or CPU Idle power states (C-states), but allowssoftware to have influence where it would otherwise be unableto express a preference.
For example, this setting may tell the hardware howaggressively or conservatively to control frequencyin the "turbo range" above the explicitly OS-controlledP-state frequency range. It may also tell the hardwarehow 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 onrelated CPUs as well (for example all CPUs on one socket), because ofhardware restrictions.Use cpupower -c all info -b to verify.
This options needs the msr kernel driver (CONFIG_X86_MSR) loaded.
--perf-bias parts written by Len Brown <len.brownAATTintel.com>Thomas Renninger <trennAATTsuse.de>
- SEE ALSO
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