geopm_agent_power_governor(7) -- agent enforces a power cap
===========================================================






Description
-----------

The :doc:`geopm::PowerGovernorAgent(3) <geopm::PowerGovernorAgent.3>` enforces a per-compute-node power cap of the
total power of all packages (sockets).

Agent Behavior Highlights
-------------------------

Policies and samples are vectors of double precision values where each
value has a meaning defined by the :doc:`geopm::Agent(3) <geopm::Agent.3>` implementation.
The Agent interface also provides methods for the Agent to extend
reports and traces with additional Agent-specific information.


*
  **Agent Name**\ :

      Set the ``--geopm-agent`` launch option or ``GEOPM_AGENT`` environment
      variable to ``"power_governor"`` and the Controller will select the
      ``PowerGovernorAgent`` for its control handler.  See :doc:`geopmlaunch(1) <geopmlaunch.1>`
      and :doc:`geopm(7) <geopm.7>` for more information about launch options and
      environment variables.

*
  **Agent Policy Definitions**\ :

  ``CPU_POWER_LIMIT``\ :
      Sets the average power cap per compute
      node in units of watts.  If ``NAN`` is
      passed for the power cap, the value
      will default to the thermal design
      power (TDP).  Each package on the node
      will be given an equal fraction of the
      total power.

*
  **Agent Sample Definitions**\ :

  ``POWER``\ :
      Median total package and DRAM power for the node in watts
      measured over the last epoch.


  ``IS_CONVERGED``\ :
      Will be ``1.0`` if the power policy has been
      enforced and the power consumption by all nodes is
      within the assigned limits, otherwise it will be
      ``0.0``.


  ``POWER_AVERAGE_ENFORCED``\ :
      Enforced power limit averaged over all
      compute nodes.  This value corresponds to
      the ``CPU_POWER_LIMIT`` policy
      field and is expected to match unless the
      policy is unachievable.

*
  **Trace Column Extensions**\ :

  ``power_budget``\ :
      Power budget assigned to the compute node associated
      with the trace file at time of sampling.


*
  **Report Extensions**\ :
  N/A

*
  **Control Loop Gate**\ :

      The agent gates the Controller's control loop to a cadence of *5ms*
      (milliseconds).

See Also
--------

:doc:`geopm(7) <geopm.7>`\ ,
:doc:`geopmagent(1) <geopmagent.1>`\ ,
:doc:`geopm_agent(3) <geopm_agent.3>`\ ,
:doc:`geopm::Agent(3) <geopm::Agent.3>`\ ,
:doc:`geopm::PowerGovernorAgent(3) <geopm::PowerGovernorAgent.3>`\ ,
:doc:`geopmlaunch(1) <geopmlaunch.1>`\ ,
:doc:`geopm_agent_monitor(7) <geopm_agent_monitor.7>`\ ,
:doc:`geopm_agent_power_balancer(7) <geopm_agent_power_balancer.7>`\ ,
:doc:`geopm_prof(3) <geopm_prof.3>`