MPI and Espresso

Color code

code

command

configuration

output

To run MPI interactively

• Login to escience0.sc.chula.ac.th, then 10.42.0.159
• Load MPI module. The command will load mpirun version 1.10.6.

module load mpi/openmpi-x86_64

• Test code mpi_hello_world.c and Makefile. Be careful, tab is tab in a Makefile, you can't use "space" instead of "tab".

// Author: Wes Kendall
// Copyright 2011 www.mpitutorial.com
// This code is provided freely with the tutorials on mpitutorial.com. Feel
// free to modify it for your own use. Any distribution of the code must
// either provide a link to www.mpitutorial.com or keep this header intact.
//
// An intro MPI hello world program that uses MPI_Init, MPI_Comm_size,
// MPI_Comm_rank, MPI_Finalize, and MPI_Get_processor_name.
//
#include <mpi.h>
#include <stdio.h>

int main(int argc, char** argv) {
  // Initialize the MPI environment. The two arguments to MPI Init are not
  // currently used by MPI implementations, but are there in case future
  // implementations might need the arguments.
  MPI_Init(NULL, NULL);

  // Get the number of processes
  int world_size;
  MPI_Comm_size(MPI_COMM_WORLD, &world_size);

  // Get the rank of the process
  int world_rank;
  MPI_Comm_rank(MPI_COMM_WORLD, &world_rank);

  // Get the name of the processor
  char processor_name[MPI_MAX_PROCESSOR_NAME];
  int name_len;
  MPI_Get_processor_name(processor_name, &name_len);

  // Print off a hello world message
  printf("Hello world from processor %s, rank %d out of %d processors\n",
         processor_name, world_rank, world_size);

  // Finalize the MPI environment. No more MPI calls can be made after this
  MPI_Finalize();
}

EXECS=mpi_hello_world
MPICC?=mpicc

all: ${EXECS}

mpi_hello_world: mpi_hello_world.c
   ${MPICC} -o mpi_hello_world mpi_hello_world.c

clean:
   rm ${EXECS}

• To run,

mpirun -np 4 mpi_hello_world

To run Espresso

• Espresso are installed in the following path. You may need to setup your own PATH (i.e. using setenv for tcsh, or export for bash shell)

/escience/software/espresso/espresso-5.2.1

-- PhatSrimanobhas - 2018-04-02