geopm_agent_power_governor(7) – agent enforces a power cap

Description

The 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 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 geopmlaunch(1) and 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

geopm(7), geopmagent(1), geopm_agent(3), geopm::Agent(3), geopm::PowerGovernorAgent(3), geopmlaunch(1), geopm_agent_monitor(7), geopm_agent_power_balancer(7), geopm_prof(3)