MaPHyS (Massively Parallel Hybrid Solver) is High performance solver for large linear algebra problems coupling direct and iterative approaches.
Home page: https://gitlab.inria.fr/solverstack/maphys/
MaPHyS (Massively Parallel Hybrid Solver) is a software package whose prototype was initially developed in the framework of the PhD thesis of Azzam Haidar (CERFACS) and further consolidated thanks to the ANR-CIS Solstice funding. This parallel linear solver couples direct and iterative approaches. The underlying idea is to apply to general unstructured linear systems domain decomposition ideas developed for the solution of linear systems arising from PDEs. The interface problem, associated with the so called Schur complement system, is solved using a block preconditioner with overlap between the blocks that is referred to as Algebraic Additive Schwarz. To cope with the possible lack of coarse grid mechanism that enables one to keep constant the number of iterations when the number of blocks is increased, the solver exploits two levels of parallelism (between the blocks and within the treatment of the blocks). This enables us to exploit a large number of processors with a moderate number of blocks which ensures a reasonable convergence behaviour. The current prototype code will be further consolidated to end-up with a high performance software package to be made freely available to the scientific community.
(extracted from HiePaCS' Proposal, a joint Project-Team with University of Bordeaux and CNRS (LaBRI UMR 5800) and Research Action between INRIA and CERFACS)