1 What: /sys/class/powercap/
4 Contact: linux-pm@vger.kernel.org
6 The powercap/ class sub directory belongs to the power cap
8 Documentation/power/powercap/powercap.rst for details.
10 What: /sys/class/powercap/<control type>
13 Contact: linux-pm@vger.kernel.org
15 A <control type> is a unique name under /sys/class/powercap.
16 Here <control type> determines how the power is going to be
17 controlled. A <control type> can contain multiple power zones.
19 What: /sys/class/powercap/<control type>/enabled
22 Contact: linux-pm@vger.kernel.org
24 This allows to enable/disable power capping for a "control type".
25 This status affects every power zone using this "control_type.
27 What: /sys/class/powercap/<control type>/<power zone>
30 Contact: linux-pm@vger.kernel.org
32 A power zone is a single or a collection of devices, which can
33 be independently monitored and controlled. A power zone sysfs
34 entry is qualified with the name of the <control type>.
35 E.g. intel-rapl:0:1:1.
37 What: /sys/class/powercap/<control type>/<power zone>/<child power zone>
40 Contact: linux-pm@vger.kernel.org
42 Power zones may be organized in a hierarchy in which child
43 power zones provide monitoring and control for a subset of
44 devices under the parent. For example, if there is a parent
45 power zone for a whole CPU package, each CPU core in it can
46 be a child power zone.
48 What: /sys/class/powercap/.../<power zone>/name
51 Contact: linux-pm@vger.kernel.org
53 Specifies the name of this power zone.
55 What: /sys/class/powercap/.../<power zone>/energy_uj
58 Contact: linux-pm@vger.kernel.org
60 Current energy counter in micro-joules. Write "0" to reset.
61 If the counter can not be reset, then this attribute is
64 What: /sys/class/powercap/.../<power zone>/max_energy_range_uj
67 Contact: linux-pm@vger.kernel.org
69 Range of the above energy counter in micro-joules.
72 What: /sys/class/powercap/.../<power zone>/power_uw
75 Contact: linux-pm@vger.kernel.org
77 Current power in micro-watts.
79 What: /sys/class/powercap/.../<power zone>/max_power_range_uw
82 Contact: linux-pm@vger.kernel.org
84 Range of the above power value in micro-watts.
86 What: /sys/class/powercap/.../<power zone>/constraint_X_name
89 Contact: linux-pm@vger.kernel.org
91 Each power zone can define one or more constraints. Each
92 constraint can have an optional name. Here "X" can have values
93 from 0 to max integer.
95 What: /sys/class/powercap/.../<power zone>/constraint_X_power_limit_uw
98 Contact: linux-pm@vger.kernel.org
100 Power limit in micro-watts should be applicable for
101 the time window specified by "constraint_X_time_window_us".
102 Here "X" can have values from 0 to max integer.
104 What: /sys/class/powercap/.../<power zone>/constraint_X_time_window_us
107 Contact: linux-pm@vger.kernel.org
109 Time window in micro seconds. This is used along with
110 constraint_X_power_limit_uw to define a power constraint.
111 Here "X" can have values from 0 to max integer.
114 What: /sys/class/powercap/<control type>/.../constraint_X_max_power_uw
117 Contact: linux-pm@vger.kernel.org
119 Maximum allowed power in micro watts for this constraint.
120 Here "X" can have values from 0 to max integer.
122 What: /sys/class/powercap/<control type>/.../constraint_X_min_power_uw
125 Contact: linux-pm@vger.kernel.org
127 Minimum allowed power in micro watts for this constraint.
128 Here "X" can have values from 0 to max integer.
130 What: /sys/class/powercap/.../<power zone>/constraint_X_max_time_window_us
133 Contact: linux-pm@vger.kernel.org
135 Maximum allowed time window in micro seconds for this
136 constraint. Here "X" can have values from 0 to max integer.
138 What: /sys/class/powercap/.../<power zone>/constraint_X_min_time_window_us
141 Contact: linux-pm@vger.kernel.org
143 Minimum allowed time window in micro seconds for this
144 constraint. Here "X" can have values from 0 to max integer.
146 What: /sys/class/powercap/.../<power zone>/enabled
149 Contact: linux-pm@vger.kernel.org
151 This allows to enable/disable power capping at power zone level.
152 This applies to current power zone and its children.