I am trying to run the attached code which can also be found on page 77 of
"Using MPI-2: Advanced Features of the Message Passing Interface."
Essentially, it is a parallel write using subarrays and ghost cells. The
problem seems to be with using user-defined datatypes in MPI_File_set_view
and MPI_File_write_all.
Here is the error I get with LAM 6.5.6 (Redhat PC), 7.0 (SunOS UltraSparc),
and 7.0 (MacOS Powerbook Ti)
Error: Unsupported datatype passed to ADIOI_Count_contiguous_blocks
Because I believe that this is associated with I/O, this email is also sent
to the ROMIO maintainers.
Thanks for your help...in advance.
-j
Source Code (it's short):
#include "mpi.h"
int main( int argc, char *argv[] )
{
int i,j,k;
int gsizes[2], distribs[2], dargs[2], psizes[2], rank, size, m,
n;
int lsizes[2], dims[2], periods[2], coords[2],
start_indices[2];
int memsizes[2];
MPI_Datatype filetype, memtype;
MPI_Comm comm;
int local_array_size, num_local_rows, num_local_cols;
int row_procs, col_procs, row_rank, col_rank;
MPI_File fh;
float *local_array;
MPI_Status status;
MPI_Init( &argc, &argv );
/* ... */
/* Jeremy Added */
m = 8; n = 9;
/* end Jeremy Added */
/* This code is particular to a 2 x 3 process decomposition */
MPI_Comm_size( MPI_COMM_WORLD, &size );
if (size != 6) {
printf( "Communicator size must be 6\n" );
MPI_Abort( MPI_COMM_WORLD, 1 );
}
/* See comments on block distribution */
row_procs = 2;
col_procs = 3;
num_local_rows = (m + row_procs - 1) / row_procs;
/* adjust for last row */
if (row_rank == row_procs-1)
num_local_rows = m - (row_procs-1) * num_local_rows;
num_local_cols = (n + col_procs - 1) / col_procs;
/* adjust for last column */
if (col_rank == col_procs-1)
num_local_cols = n - (col_procs-1) * num_local_cols;
local_array = (float *)malloc( num_local_rows * num_local_cols *
sizeof(floa
t) );
/* ... set elements of local_array ... */
/* Jeremy Added */
MPI_Comm_rank(MPI_COMM_WORLD,&k);
for(i=0;i<num_local_rows;i++){
for(j=0;j<num_local_cols; j++){
local_array[i*num_local_cols + j] = k+1.0;
}
}
/* end Jeremy Added */
gsizes[0] = m; gsizes[1] = n;
/* no. of rows and columns in global array*/
psizes[0] = 2; psizes[1] = 3;
/* no. of processes in vertical and horizontal dimensions
of process grid */
lsizes[0] = m/psizes[0]; /* no. of rows in local array */
lsizes[1] = n/psizes[1]; /* no. of columns in local array */
dims[0] = 2; dims[1] = 3;
periods[0] = periods[1] = 1;
MPI_Cart_create(MPI_COMM_WORLD, 2, dims, periods, 0, &comm);
MPI_Comm_rank(comm, &rank);
MPI_Cart_coords(comm, rank, 2, coords);
/* global indices of the first element of the local array */
start_indices[0] = coords[0] * lsizes[0];
start_indices[1] = coords[1] * lsizes[1];
MPI_Type_create_subarray(2, gsizes, lsizes, start_indices,
MPI_ORDER_C, MPI_FLOAT, &filetype);
MPI_Type_commit(&filetype);
MPI_File_open(MPI_COMM_WORLD, "datafile",
MPI_MODE_CREATE | MPI_MODE_WRONLY,
MPI_INFO_NULL, &fh);
MPI_File_set_view(fh, 0, MPI_FLOAT, filetype, "native",
MPI_INFO_NULL);
/* create a derived datatype that describes the layout of the local
array in the memory buffer that includes the ghost area. This is
another subarray datatype! */
memsizes[0] = lsizes[0] + 2; /* no. of rows in allocated array */
memsizes[1] = lsizes[1] + 2; /* no. of columns in allocated array */
start_indices[0] = start_indices[1] = 1;
/* indices of the first element of the local array in the
allocated array */
MPI_Type_create_subarray(2, memsizes, lsizes, start_indices,
MPI_ORDER_C, MPI_FLOAT, &memtype);
MPI_Type_commit(&memtype);
MPI_File_write_all(fh, local_array, 1, memtype, &status);
MPI_File_close(&fh);
/* ... */
MPI_Finalize();
return 0;
}
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