cpupower-set man page on Oracle

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CPUPOWER-SET(1)			cpupower Manual		       CPUPOWER-SET(1)

       cpupower-set  - Set processor power related kernel or hardware configu‐

       cpupower set [ -b VAL ] [ -s VAL ] [ -m VAL ]

       cpupower set  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  configura‐
       tions  is described in the cpupower(1) manpage in the --cpu option sec‐
       tion. Whether an option affects the whole system or can be  applied  to
       individual cores is described in the Options sections.

       Use  cpupower  info   to read out current settings and whether they are
       supported on the system at all.

       --perf-bias, -b
	   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

	   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-

	   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  set‐
	   ting	 on related CPUs as well (for example all CPUs on one socket),
	   because of hardware restrictions.  Use cpupower -c all info	-b  to

	   This options needs the msr kernel driver (CONFIG_X86_MSR) loaded.

       --sched-mc,  -m [ VAL ]
       --sched-smt, -s [ VAL ]
	   --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 nega‐
	   tiv) 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:
	     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

       cpupower-info(1), cpupower-monitor(1), powertop(1)

       --perf-bias parts written by Len Brown <len.brown@intel.com>
       Thomas Renninger <trenn@suse.de>

				  22/02/2011		       CPUPOWER-SET(1)

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