NAME

       rapl-set - set RAPL configurations

SYNPOSIS

       rapl-set [OPTION]...

DESCRIPTION

       Sets Intel Running Average Power Limit (RAPL) configurations.

       Note that the -p and -z options are different from powercap-set(1).

       This  software  requires  an Intel processor (Sandy Bridge or newer), Linux kernel 3.13 or
       newer compiled with CONFIG_POWERCAP and  CONFIG_INTEL_RAPL  enabled,  and  the  intel_rapl
       kernel module to be loaded.

OPTIONS

       -h, --help
              Prints out the help screen

       -p, --zone=ZONE
              The zone number (0 by default)

       -p, --package=PACKAGE
              Deprecated, use --zone instead

       -z, --subzone=SUBZONE
              The subzone number (none by default)

       -c, --constraint=CONSTRAINT
              The constraint number (none by default)

       The following zone-level arguments may be used together (-z/--subzone is optional):

       -j, --z-energy
              Reset zone energy counter

       -e, --z-enabled=1|0
              Enable/disable a zone

       The  following constraint-level arguments may be used together and require -c/--constraint
       (-z/--subzone is optional):

       -l, --c-power-limit=UW
              Set constraint power limit

       -s, --c-time-window=US
              Set constraint time window

EXAMPLES

       Note that -p/--zone=0 is used by default, allowing for simpler commands  on  single-socket
       systems.

       rapl-set -e 1
              Enable zone 0 (implicitly), which is usually named package-0.

       rapl-set -p 0 -e 1
              Enable zone 0 (explicitly).

       rapl-set -p 0 -z 1 -e 1
              Enable zone 0, subzone 1, which is usually the uncore or dram subzone of package-0,
              depending on the system.

       rapl-set -p 0 -c 1 -l 25000000
              Set a power cap of 25 Watts (25000000 uW) on zone 0, constraint 1, which is usually
              the short_term constraint for package-0.

       rapl-set -p 1 -z 0 -c 0 -l 15000000 -s 976
              Set  a  power  cap of 15 Watts (15000000 uW) and time window of 976 microseconds on
              zone 1, subzone 0,  constraint  0,  which  is  usually  the  long_term  (and  only)
              constraint for the core subzone of package-1 (a multi-socket system).

REMARKS

       Administrative (root) privileges are usually needed to use rapl-set.

       Setting  constraint  power  cap  and/or  time  limit  values  does not enable or disable a
       zone/subzone - the -e/--z-enabled flag must be set explicitly.

       Power units: microwatts (uW)
       Time units: microseconds (us)

BUGS

       The following are behavioral quirks due to the kernel interface or abnormalities  in  some
       hardware.  They are not bugs in rapl-set and should not be reported as such.

       The  kernel  is  not  guaranteed  to  accept power limit and time window values exactly as
       specified.  Values may be rounded due to how they are encoded in Model-Specific Registers.
       This  rounding  error  is  usually  small  within  normal  operating  ranges,  but  can be
       significant at the extremes.

       Some systems may not accept time window values correctly, requiring  a  system  reboot  to
       reset the time window to the default value.

       Values  returned  by  the  kernel, e.g., by rapl-info(1), sometimes lose accuracy from the
       actual stored value due to integer rounding.  For example, the kernel may  return  a  time
       window  value of 7812 us, when in fact the actual stored value is 7812.5 us.  Writing back
       an integer value returned by the kernel may cause unexpected changes to its  stored  value
       due to these rounding problems.

       At  the time of this writing, some features in the powercap interface are not supported by
       RAPL.  Resetting a zone energy counter (-j/--z-energy) may result in an EACCES (Permission
       denied) error due to the energy_uj file being read-only.

       Some systems may not allow disabling package-level zones/constraints.

       It  is  possible  for  packages  on multi-socket systems to be indexed out of order by the
       kernel.  For example, the package at index 0 (-p 0)  could  actually  be  named  package-1
       while  the  package at index 1 (-p 1) is named package-0.  If this matters to the user, it
       is their responsibility to check before setting values, e.g., using rapl-info(1).

       Report bugs upstream at <https://github.com/powercap/powercap>

FILES

       /sys/devices/virtual/powercap/intel-rapl/*
       /sys/class/powercap/intel-rapl/*

AUTHORS

       Connor Imes <connor.k.imes@gmail.com>

SEE ALSO

       powercap-info(1), powercap-set(1), rapl-info(1)