| |
| c--------------------------------------------------------------------- |
| c--------------------------------------------------------------------- |
| |
| subroutine setup_mpi |
| |
| c--------------------------------------------------------------------- |
| c--------------------------------------------------------------------- |
| |
| c--------------------------------------------------------------------- |
| c set up MPI stuff |
| c--------------------------------------------------------------------- |
| |
| implicit none |
| include 'mpinpb.h' |
| include 'npbparams.h' |
| integer error, color, nc |
| |
| call mpi_init(error) |
| |
| call mpi_comm_size(MPI_COMM_WORLD, total_nodes, error) |
| call mpi_comm_rank(MPI_COMM_WORLD, node, error) |
| |
| if (.not. convertdouble) then |
| dp_type = MPI_DOUBLE_PRECISION |
| else |
| dp_type = MPI_REAL |
| endif |
| |
| c--------------------------------------------------------------------- |
| c compute square root; add small number to allow for roundoff |
| c--------------------------------------------------------------------- |
| nc = dint(dsqrt(dble(total_nodes) + 0.00001d0)) |
| |
| c--------------------------------------------------------------------- |
| c We handle a non-square number of nodes by making the excess nodes |
| c inactive. However, we can never handle more cells than were compiled |
| c in. |
| c--------------------------------------------------------------------- |
| |
| if (nc .gt. maxcells) nc = maxcells |
| if (node .ge. nc*nc) then |
| active = .false. |
| color = 1 |
| else |
| active = .true. |
| color = 0 |
| end if |
| |
| call mpi_comm_split(MPI_COMM_WORLD,color,node,comm_setup,error) |
| if (.not. active) return |
| |
| call mpi_comm_size(comm_setup, no_nodes, error) |
| call mpi_comm_dup(comm_setup, comm_solve, error) |
| call mpi_comm_dup(comm_setup, comm_rhs, error) |
| |
| c--------------------------------------------------------------------- |
| c let node 0 be the root for the group (there is only one) |
| c--------------------------------------------------------------------- |
| root = 0 |
| |
| return |
| end |
| |
