This PR enables GASNet-level shared-memory bypass communication for all GASNet conduits (in fast/large segment modes), which should notably greatly accelerate co-locale communication for CHPL_COMM=gasnet CHPL_COMM_SUBSTRATE=ibv.
This fixes the defect acknowledged in the original PR #13473 regarding use of PSHM with CHPL_COMM_SUBSTRATE=ibv.
TODO:
This PR has not yet been tested for correctness or performance, and thus should be considered a proof-of-concept.
The PR currently only modifies the GASNet-EX backend (i.e. CHPL_GASNET_VERSION=ex). Assuming it proves valuable there, then an analogous change probably must be back-ported to the legacy GASNet-1 backend, to avoid breaking it in the presence of co-locales.
Overview
This PR enables GASNet-level shared-memory bypass communication for all GASNet conduits (in fast/large segment modes), which should notably greatly accelerate co-locale communication for
CHPL_COMM=gasnet CHPL_COMM_SUBSTRATE=ibv.This fixes the defect acknowledged in the original PR #13473 regarding use of PSHM with
CHPL_COMM_SUBSTRATE=ibv.TODO:
CHPL_GASNET_VERSION=ex). Assuming it proves valuable there, then an analogous change probably must be back-ported to the legacy GASNet-1 backend, to avoid breaking it in the presence of co-locales.CC: @PHHargrove , @ronawho , @jhh67