You might give it a try with 1.8.1 or the nightly snapshot from 1.8.2 - we
updated ROMIO since the 1.6 series, and whatever fix is required may be in the
newer version
On May 14, 2014, at 6:52 AM, CANELA-XANDRI Oriol
<oriol.canela-xan...@roslin.ed.ac.uk> wrote:
> Hello,
>
> I am using MPI IO for writing/reading a block cyclic distribution matrix
> into a file.
>
> It works fine except when there is some MPI threads with no data (i.e. when
> the matrix is small enough, or the block size is big enough that some
> processes in the grid do not have any matrix block). In this case, I receive
> an error when calling MPI_File_set_view saying that the data cannot be freed.
> I tried with 1.3 and 1.6 versions. When I try with MPICH it works without
> errors. Could this be a bug?
>
> My function is (where nBlockRows/nBlockCols define the size of the blocks,
> nGlobRows/nGlobCols define the global size of the matrix, nProcRows/nProcCols
> define the dimensions of the process grid, and fname is the name of the
> file.):
>
> void Matrix::writeMatrixMPI(std::string fname) {
> int dims[] = {this->nGlobRows, this->nGlobCols};
> int dargs[] = {this->nBlockRows, this->nBlockCols};
> int distribs[] = {MPI_DISTRIBUTE_CYCLIC, MPI_DISTRIBUTE_CYCLIC};
> int dim[] = {communicator->nProcRows, communicator->nProcCols};
> char nat[] = "native";
> int rc;
> MPI_Datatype dcarray;
> MPI_File cFile;
> MPI_Status status;
>
> MPI_Type_create_darray(communicator->mpiNumTasks, communicator->mpiRank, 2,
> dims, distribs, dargs, dim, MPI_ORDER_FORTRAN, MPI_DOUBLE, &dcarray);
> MPI_Type_commit(&dcarray);
>
> std::vector<char> fn(fname.begin(), fname.end());
> fn.push_back('\0');
> rc = MPI_File_open(MPI_COMM_WORLD, &fn[0], MPI_MODE_CREATE |
> MPI_MODE_WRONLY, MPI_INFO_NULL, &cFile);
> if(rc){
> std::stringstream ss;
> ss << "Error: Failed to open file: " << rc;
> misc.error(ss.str(), 0);
> }
> else
> {
> MPI_File_set_view(cFile, 0, MPI_DOUBLE, dcarray, nat, MPI_INFO_NULL);
> MPI_File_write_all(cFile, this->m, this->nRows*this->nCols, MPI_DOUBLE,
> &status);
> }
> MPI_File_close(&cFile);
> MPI_Type_free(&dcarray);
> }
>
> Best regards,
>
> Oriol
>
> --
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> Scotland, with registration number SC005336.
>
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