To facilitate synchronizing wisdom among the different MPI processes, we provide two functions:
void fftw_mpi_gather_wisdom(MPI_Comm comm);
void fftw_mpi_broadcast_wisdom(MPI_Comm comm);
The fftw_mpi_gather_wisdom function gathers all wisdom in the
given communicator comm to the process of rank 0 in the
communicator: that process obtains the union of all wisdom on all the
processes. As a side effect, some other processes will gain
additional wisdom from other processes, but only process 0 will gain
the complete union.
The fftw_mpi_broadcast_wisdom does the reverse: it exports
wisdom from process 0 in comm to all other processes in the
communicator, replacing any wisdom they currently have.
See FFTW MPI Wisdom.