Michael, As far as I know none of the implementations of the neighborhood collectives in OMPI are architecture-aware. The only 2 components that provide support for neighborhood collectives are basic (for the blocking version) and libnbc (for the non-blocking versions).
George. On Wed, Jun 8, 2022 at 1:27 PM Michael Thomadakis via users < users@lists.open-mpi.org> wrote: > Hello OpenMPI > > I was wondering if the MPI_Neighbor_xxxxx calls have received any special > design and optimizations in OpenMPI 4.1.x+ for these patterns of > communication. > > For instance, these could benefit from proximity awareness and intra- vs > inter-node communications. However, even single node communications have > hierarchical structure due to the increased number of num-domains, larger > L3 caches and so on. > > Is OpenMPI 4.1.x+ leveraging any special logic to optimize these calls? > Is UCX or UCC/HCOLL doing anything special or is OpenMPI using these lower > layers in a more "intelligent" way to provide > optimized neighborhood collectives? > > Thanks you much > Michael >
