A collection of MPI-IO example programs

List of example programs

• mpi_file_open.c
  • Calls MPI_File_open function to create a new file.
  • Calls MPI_File_open function to open an existing file.
• mpi_file_set_view.c
  • Set the visible file region to each process.
• print_mpi_io_hints.c
  • Prints out all default MPI I/O hints.
• mpi_tag_ub.c
  • Obtains the value of attribute MPI_TAG_UB attached to communicator MPI_COMM_WORLD. MPI_TAG_UB is the upper bound for tag value.
• fileview_subarray.c
  • Uses MPI_Type_create_subarray() to create an MPI derived data type of a 2D subarray to a 2D global array, which is then used in the call to MPI_File_set_view().
• ghost_cell.c
  • Writes a 2D local array with ghost cells to a global array in a file. Ghost cells are the elements in the local array that are not written to the file. This example shows how to define an MPI derived data type to describe a 2D subarray with ghost cells used it in I/O.
• indexed_fsize.c
  • Uses a file datatype constructed from multiple subarray datatypes concatenated by MPI_Type_indexed(). Each variable is partitioned among processes in a 2D block-block fashion. At the end, it checks the file size whether or not it is expected.
• hindexed_fsize.c
  • Uses a file datatype constructed from multiple subarray datatypes concatenated by MPI_Type_create_hindexed(). Each variable is partitioned among processes in a 2D block-block fashion. At the end, it checks the file size whether or not it is expected.
• struct_fsize.c
  • Similar to indexed_fsize.c, but using MPI_Type_create_struct() to concatenate multiple subarray datatypes.
• nvars.c
  • Makes a single call to collective write and read by using a fileview of concatenating multiple subarrays of variables stored in the file and each variable is partitioned among processes in a 2D block-block fashion.
• column-wise.c
  • Uses a 2D column-wise data partitioning pattern to set a file view.

To compile

• Modify file Makefile if necessary to change the path of MPI C compiler.
• Run command make [name of example program]

Useful links to learn MPI

• MPI Forum
• MPICH, an implementation of MPI standard
• OpenMPI, an implementation of MPI standard
• Book - MPI: The Complete Reference

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email: wkliao@eecs.northwestern.edu

Copyright (C) 2019, Northwestern University.

See COPYRIGHT notice in top-level directory.