10     MPI_Comm_size(MPI_COMM_WORLD, &world_size);
 
   14     MPI_Comm_rank(MPI_COMM_WORLD, &world_rank);
 
   17     char processor_name[MPI_MAX_PROCESSOR_NAME];
 
   19     MPI_Get_processor_name(processor_name, &name_len);
 
   22     printf(
"Hello world from Xeon processor %s, rank %d" 
   23            " out of %d processors\n",
 
   24            processor_name, world_rank, world_size);
 
int main(int argc, char **argv)