Argonne National Laboratory

Adjoining Basic Idioms of MPI One-Sided Communications and Efficiency Implications

TitleAdjoining Basic Idioms of MPI One-Sided Communications and Efficiency Implications
Publication TypeReport
Year of Publication2014
AuthorsHascoet, L, Schanen, M, Utke, J
Other NumbersANL/MCS-P5089-0214
AbstractComputing gradients of numerical models by the adjoint mode of algorithmic differentiation is a crucial ingredient for model optimization, sensitivity analysis, and uncertainty quantification of many large-scale science and engineering applications. The adjoint mode implies a reversal of the data dependencies and consequently a reversal of communications in parallelized models. Building on previous studies regarding the adjoining of MPI two-sided communications, we investigate the construction of adjoints for certain one-sided MPI communications and the overhead their use implies for the adjoint. Runtime experiments on a matrix vector product test code illustrate the nontrivial choices for the adjoint construction.