HPL_grid_init man page
HPL_grid_init — Create a process grid.
int HPL_grid_init( MPI_Comm COMM, const HPL_T_ORDER ORDER, const int NPROW, const int NPCOL, HPL_T_grid * GRID );
HPL_grid_init creates a NPROW x NPCOL process grid using column- or row-major ordering from an initial collection of processes identified by an MPI communicator. Successful completion is indicated by the returned error code MPI_SUCCESS. Other error codes depend on the MPI implementation. The coordinates of processes that are not part of the grid are set to values outside of [0..NPROW) x [0..NPCOL).
- COMM (global/local input) MPI_Comm
On entry, COMM is the MPI communicator identifying the initial collection of processes out of which the grid is formed.
- ORDER (global input) const HPL_T_ORDER
On entry, ORDER specifies how the processes should be ordered in the grid as follows:
ORDER = HPL_ROW_MAJOR row-major ordering;
ORDER = HPL_COLUMN_MAJOR column-major ordering;
- NPROW (global input) const int
On entry, NPROW specifies the number of process rows in the grid to be created. NPROW must be at least one.
- NPCOL (global input) const int
On entry, NPCOL specifies the number of process columns in the grid to be created. NPCOL must be at least one.
- GRID (local input/output) HPL_T_grid *
On entry, GRID points to the data structure containing the process grid information to be initialized.
HPL_pnum (3), HPL_grid_info (3), HPL_grid_exit (3).