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diff --git a/tools/power/cpupower/man/cpupower-set.1 b/tools/power/cpupower/man/cpupower-set.1 new file mode 100644 index 000000000000..c4954a9fe4e7 --- /dev/null +++ b/tools/power/cpupower/man/cpupower-set.1 @@ -0,0 +1,103 @@ +.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 ] [ \-s VAL ] [ \-m 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 +.PP +\-\-sched\-mc, \-m [ VAL ] +.RE +\-\-sched\-smt, \-s [ VAL ] +.RS 4 +\-\-sched\-mc utilizes cores in one processor package/socket first before +processes are scheduled to other processor packages/sockets. + +\-\-sched\-smt utilizes thread siblings of one processor core first before +processes are scheduled to other cores. + +The impact on power consumption and performance (positiv or negativ) heavily +depends on processor support for deep sleep states, frequency scaling and +frequency boost modes and their dependencies between other thread siblings +and processor cores. + +Taken over from kernel documentation: + +Adjust the kernel's multi-core scheduler support. + +Possible values are: +.RS 2 +0 - No power saving load balance (default value) + +1 - Fill one thread/core/package first for long running threads + +2 - Also bias task wakeups to semi-idle cpu package for power +savings +.RE + +sched_mc_power_savings is dependent upon SCHED_MC, which is +itself architecture dependent. + +sched_smt_power_savings is dependent upon SCHED_SMT, which +is itself architecture dependent. + +The two files are independent of each other. It is possible +that one file may be present without the other. + +.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> |