e23feb1668
Added power cap framework documentation. This explains the use of power capping framework, sysfs and programming interface. There are two documents: - Documentation/power/powercap/powercap.txt : Explains use case and APIs. - Documentation/ABI/testing/sysfs-class-powercap: Explains ABIs. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Len Brown <len.brown@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
153 lines
4.9 KiB
Plaintext
153 lines
4.9 KiB
Plaintext
What: /sys/class/powercap/
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Date: September 2013
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KernelVersion: 3.13
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Contact: linux-pm@vger.kernel.org
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Description:
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The powercap/ class sub directory belongs to the power cap
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subsystem. Refer to
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Documentation/power/powercap/powercap.txt for details.
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What: /sys/class/powercap/<control type>
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Date: September 2013
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KernelVersion: 3.13
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Contact: linux-pm@vger.kernel.org
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Description:
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A <control type> is a unique name under /sys/class/powercap.
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Here <control type> determines how the power is going to be
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controlled. A <control type> can contain multiple power zones.
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What: /sys/class/powercap/<control type>/enabled
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Date: September 2013
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KernelVersion: 3.13
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Contact: linux-pm@vger.kernel.org
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Description:
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This allows to enable/disable power capping for a "control type".
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This status affects every power zone using this "control_type.
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What: /sys/class/powercap/<control type>/<power zone>
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Date: September 2013
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KernelVersion: 3.13
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Contact: linux-pm@vger.kernel.org
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Description:
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A power zone is a single or a collection of devices, which can
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be independently monitored and controlled. A power zone sysfs
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entry is qualified with the name of the <control type>.
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E.g. intel-rapl:0:1:1.
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What: /sys/class/powercap/<control type>/<power zone>/<child power zone>
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Date: September 2013
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KernelVersion: 3.13
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Contact: linux-pm@vger.kernel.org
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Description:
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Power zones may be organized in a hierarchy in which child
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power zones provide monitoring and control for a subset of
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devices under the parent. For example, if there is a parent
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power zone for a whole CPU package, each CPU core in it can
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be a child power zone.
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What: /sys/class/powercap/.../<power zone>/name
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Date: September 2013
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KernelVersion: 3.13
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Contact: linux-pm@vger.kernel.org
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Description:
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Specifies the name of this power zone.
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What: /sys/class/powercap/.../<power zone>/energy_uj
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Date: September 2013
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KernelVersion: 3.13
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Contact: linux-pm@vger.kernel.org
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Description:
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Current energy counter in micro-joules. Write "0" to reset.
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If the counter can not be reset, then this attribute is
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read-only.
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What: /sys/class/powercap/.../<power zone>/max_energy_range_uj
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Date: September 2013
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KernelVersion: 3.13
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Contact: linux-pm@vger.kernel.org
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Description:
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Range of the above energy counter in micro-joules.
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What: /sys/class/powercap/.../<power zone>/power_uw
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Date: September 2013
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KernelVersion: 3.13
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Contact: linux-pm@vger.kernel.org
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Description:
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Current power in micro-watts.
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What: /sys/class/powercap/.../<power zone>/max_power_range_uw
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Date: September 2013
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KernelVersion: 3.13
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Contact: linux-pm@vger.kernel.org
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Description:
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Range of the above power value in micro-watts.
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What: /sys/class/powercap/.../<power zone>/constraint_X_name
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Date: September 2013
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KernelVersion: 3.13
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Contact: linux-pm@vger.kernel.org
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Description:
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Each power zone can define one or more constraints. Each
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constraint can have an optional name. Here "X" can have values
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from 0 to max integer.
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What: /sys/class/powercap/.../<power zone>/constraint_X_power_limit_uw
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Date: September 2013
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KernelVersion: 3.13
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Contact: linux-pm@vger.kernel.org
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Description:
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Power limit in micro-watts should be applicable for
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the time window specified by "constraint_X_time_window_us".
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Here "X" can have values from 0 to max integer.
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What: /sys/class/powercap/.../<power zone>/constraint_X_time_window_us
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Date: September 2013
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KernelVersion: 3.13
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Contact: linux-pm@vger.kernel.org
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Description:
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Time window in micro seconds. This is used along with
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constraint_X_power_limit_uw to define a power constraint.
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Here "X" can have values from 0 to max integer.
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What: /sys/class/powercap/<control type>/.../constraint_X_max_power_uw
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Date: September 2013
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KernelVersion: 3.13
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Contact: linux-pm@vger.kernel.org
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Description:
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Maximum allowed power in micro watts for this constraint.
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Here "X" can have values from 0 to max integer.
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What: /sys/class/powercap/<control type>/.../constraint_X_min_power_uw
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Date: September 2013
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KernelVersion: 3.13
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Contact: linux-pm@vger.kernel.org
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Description:
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Minimum allowed power in micro watts for this constraint.
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Here "X" can have values from 0 to max integer.
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What: /sys/class/powercap/.../<power zone>/constraint_X_max_time_window_us
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Date: September 2013
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KernelVersion: 3.13
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Contact: linux-pm@vger.kernel.org
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Description:
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Maximum allowed time window in micro seconds for this
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constraint. Here "X" can have values from 0 to max integer.
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What: /sys/class/powercap/.../<power zone>/constraint_X_min_time_window_us
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Date: September 2013
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KernelVersion: 3.13
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Contact: linux-pm@vger.kernel.org
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Description:
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Minimum allowed time window in micro seconds for this
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constraint. Here "X" can have values from 0 to max integer.
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What: /sys/class/powercap/.../<power zone>/enabled
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Date: September 2013
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KernelVersion: 3.13
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Contact: linux-pm@vger.kernel.org
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Description
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This allows to enable/disable power capping at power zone level.
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This applies to current power zone and its children.
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