geopm_ctl(3) – GEOPM runtime control thread

Synopsis

#include <geopm_ctl.h>

Link with -lgeopm

int geopm_ctl_create(MPI_Comm comm,
                     struct geopm_ctl_c **ctl);

int geopm_ctl_destroy(struct geopm_ctl_c *ctl);

int geopm_ctl_run(struct geopm_ctl_c *ctl);

int geopm_ctl_pthread(struct geopm_ctl_c *ctl,
                      const pthread_attr_t *attr,
                      pthread_t *thread);

Description

The geopm_ctl_c structure is used to launch the global extensible open power manager algorithm. There are several ways to enable control: running the control algorithm as a distinct processes from the application under control, or running the control algorithm as a separate pthread owned by the application process under control. Each of these methods has different requirements and trade offs.

  • geopm_ctl_create(): creates a geopm_ctl_c object, ctl which is an opaque structure that holds the state used to execute the control algorithm with one of the other functions described in this man page. The control algorithm relies on feedback about the application profile. The user provides an MPI communicator, comm which must have at least one process running on every compute node under control.

  • geopm_ctl_destroy(): destroys all resources associated with the ctl structure which allocated by a previous call to geopm_ctl_create().

  • geopm_ctl_run(): steps the control algorithm continuously until the application signals shutdown.

  • geopm_ctl_pthread(): creates a POSIX thread running the control algorithm continuously until the application signals shutdown. With this method of launch the supporting MPI implementation must be enabled for MPI_THREAD_MULTIPLE using MPI_Init_thread().

Errors

All functions described on this man page return an error code. See geopm_error(3) for a full description of the error numbers and how to convert them to strings.

See Also

geopm(7), geopm_error(3), geopm_sched(3), geopmctl(1)