diff options
Diffstat (limited to 'tools/power/cpupower/man/cpupower-set.1')
-rw-r--r-- | tools/power/cpupower/man/cpupower-set.1 | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/tools/power/cpupower/man/cpupower-set.1 b/tools/power/cpupower/man/cpupower-set.1 new file mode 100644 index 0000000000..2bcc696f44 --- /dev/null +++ b/tools/power/cpupower/man/cpupower-set.1 @@ -0,0 +1,65 @@ +.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> |