power/powercap/powercap.rst

5 The power capping framework provides a consistent interface between the kernel
6 and the user space that allows power capping drivers to expose the settings to
12 The framework exposes power capping devices to user space via sysfs in the
14 'control types', which correspond to different methods of power capping.  For
17 corresponds to the use of idle injection for controlling power.
20 monitored using the power capping method determined by the control type the
21 given zone belongs to. They each contain attributes for monitoring power, as
22 well as controls represented in the form of power constraints.  If the parts of
23 the system represented by different power zones are hierarchical (that is, one
24 bigger part consists of multiple smaller parts that each have their own power
25 controls), those power zones may also be organized in a hierarchy with one
26 parent power zone containing multiple subzones and so on to reflect the power
27 control topology of the system.  In that case, it is possible to apply power
28 capping to a set of devices together using the parent power zone and if more
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150 control type called intel-rapl which contains two power zones, intel-rapl:0 and
151 intel-rapl:1, representing CPU packages.  Each of these power zones contains
156 to be applied (the constraints in the 'package' power zones apply to the whole
159 power value, there is no power_uw attribute.
161 In addition to that, each power zone contains a name attribute, allowing the
170 Depending on different power zones, the Intel RAPL technology allows
171 one or multiple constraints like short term, long term and peak power,
172 with different time windows to be applied to each power zone.
174 power limits and the sizes of the time windows. Note that time window
175 is not applicable to peak power. Here, constraint_j_* attributes
204 	Current power in micro watts.
207 	Range of the above power value in micro-watts.
210 	Name of this power zone.
212 It is possible that some domains have both power ranges and energy counter ranges;
229 	Maximum allowed power in micro watts.
232 	Minimum allowed power in micro watts.
254 Call powercap_register_zone() to register a power zone (under a given
255 control type), either as a top-level power zone or as a subzone of another
256 power zone registered earlier.
257 The number of constraints in a power zone and the corresponding callbacks have
260 To Free a power zone call powercap_unregister_zone().