Using funneled will make your code more portable in the long run as it is guaranteed by the MPI standard. Using single, i.e. MPI_Init, is working now for typical OpenMP+MPI program that MPI calls are outside OpenMP sections. But as MPI implementations implement more performance optimized feature that distingushes single and funneled, then you need to use funneled to use those implementations.
A.Chan ----- "Yuanyuan ZHANG" <zhang.yuany...@jp.fujitsu.com> wrote: > Hi all, > > I can understand the difference between SINGLE and FUNNELED, and why > I > should use FUNNELED now. Thank you! > > Yuanyuan > > > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users