Locality-Aware MPI

This repository performs locality-aware optimizations for standard MPI collectives as well as neighborhood collectives.

Collective Optimizations

The collective optimizations are within the folder src/collective.

Allgather :

The file allgather.c contains methods for performing the bruck allgather, the ring allgather, and point-to-point communication (all processes perform Isends and Irecvs with each other process). Each version also contains a locality-aware optimization.

Alltoall :

The file alltoall.c contains methods for performing the bruck alltoall algorithm and point-to-point communication (all processes perform Isends and Irecvs with each other process). This file contains locality-aware aggregation for the p2p version, and a locality-aware bruck alltoall is in progress.

Alltoallv :

The file alltoallv.c contains point-to-point communication for the all-to-allv operation, and a locality-aware optimization for this. A persistent version of the locality-aware alltoallv is in progress to improve load balancing without significant overheads.

Neighborhood Collectives :

The neighborhood collective operations are within the folder src/neighborhood.

Dist Graph Create :

To use the MPI Advance optimizations for neighborhood collectives, create the topology communicator with MPIX_Dist_graph_create_adjacent (in dist_graph.c).

Neighbor Alltoallv :

A standard neighbor alltoallv and locality-aware version are both implemented in neighbor.c. To use these, call the dist graph create adjacent method above, followed by MPIX_Neighbor_alltoallv_init().

Neighbor Alltoallv :

A standard neighbor alltoallw version is implemented in neighbor.c. To use this, call the dist graph create adjacent method above, followed by MPIX_Neighbor_alltoallw_init().