PT-Scotch: A tool for efficient parallel graph ordering

Cédric Chevalier (1, 2) , François Pellegrini (1, 2)

1 LaBRI - Laboratoire Bordelais de Recherche en Informatique
2 SCALAPPLIX - Algorithms and high performance computing for grand challenge applications

The parallel ordering of large graphs is a difficult problem, because on the one hand minimum degree algorithms do not parallelize well, and on the other hand the obtainment of high quality orderings with the nested dissection algorithm requires efficient graph bipartitioning heuristics, the best sequential implementations of which are also hard to parallelize. This paper presents a set of algorithms, implemented in the PT-Scotch software package, which allows one to order large graphs in parallel, yielding orderings the quality of which is only slightly worse than the one of state-of-the-art sequential algorithms. Our implementation uses the classical nested dissection approach but relies on several novel features to solve the parallel graph bipartitioning problem. Thanks to these improvements, PT-Scotch produces consistently better orderings than ParMeTiS on large numbers of processors.

Mots clés: Parallel graph ordering; Nested dissection; Distributed memory computer; Multi-threading

Domaines: Calcul parallèle, distribué et partagé [cs.DC]

Cédric Chevalier, François Pellegrini. PT-Scotch: A tool for efficient parallel graph ordering. Parallel Computing, 2008, 34 (6-8), pp.318-331. ⟨10.1016/j.parco.2007.12.001⟩. ⟨hal-00402893⟩