Function broadcast_variable_grids

src/execution_algorithms/kfac.cpp:1185–1211

Broadcast the variabes in sub-grid parallelism

}
// Broadcast the variabes in sub-grid parallelism
int broadcast_variable_grids(int variable, lbann_comm* comm)
{

  El::Int variable_local[1], recvMetaData[1];
  if (comm->get_grid_type() == GridType::PRIMARY_GRID) {
    variable_local[0] = variable;
  }
  else if (comm->get_grid_type() == GridType::SECONDARY_GRID) {
    variable_local[0] = 0;
  }

  if (comm->get_grid_type() == GridType::PRIMARY_GRID or
      comm->get_grid_type() == GridType::SECONDARY_GRID) {
    El::SyncInfo<El::Device::CPU> syncGeneralCPU =
      El::SyncInfo<El::Device::CPU>();
    El::mpi::AllReduce(variable_local,
                       recvMetaData,
                       1,
                       El::mpi::MAX,
                       comm->get_combined_grid_comm(),
                       syncGeneralCPU);
    return recvMetaData[0];
  }
  else {
    return 0;
  }
}

// =============================================
// KFAC implementation