Packing the data

Packing the Data

  integer soffset

  soffset = istep*r
  pos = 0
  call mpi_pack (gindex, 1, MPI_INTEGER,
                 tbuf1, bytesinbuf, pos, comm, ierr)
  call mpi_pack (a(soffset), nsuperblks, newtype,
                 tbuf1, bytesinbuf, pos, comm, ierr)

• First we pack the global index of the first block to be sent.
• Then we pack the blocks, taking one block from each superblock.
• Extra memory is required for the packing and unpacking buffers.