Section: Software
MUMPS
Participants : Maurice Brémond, Indranil Chowdhury, Guillaume Joslin, Jean-Yves L'Excellent [ correspondent ] , Bora Uçar.
Mumps (for MUltifrontal Massively Parallel Solver , see http://graal.ens-lyon.fr/MUMPS ) is a software package for the solution of large sparse systems of linear equations. The development of Mumps was initiated by the European project PARASOL (Esprit 4, LTR project 20160, 1996-1999), whose results and developments were public domain. Since then, mainly in collaboration with ENSEEIHT-IRIT (Toulouse, France), lots of developments have been done, to enhance the software with more functionalities and integrate recent research work. Recent developments also involve the former Inria project ScAlAppliX since the recruitment of Abdou Guermouche as an assistant professor at LaBRI , while Cerfacs contributes to some research work.
Mumps implements a direct method, the multifrontal method, and is a parallel code for distributed memory computers; it is unique by the performance obtained and the number of functionalities available, among which we can cite:
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various types of systems: symmetric positive definite, general symmetric, or unsymmetric,
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several matrix input formats: assembled or expressed as a sum of elemental matrices, centralized on one processor or pre-distributed on the processors,
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detection of null pivots,
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preprocessing and scaling for symmetric and unsymmetric matrices,
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partial factorization and Schur complement matrix,
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dense or sparse right-hand sides, centralized or distributed solution,
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real or complex arithmetic, single or double precision,
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partial threshold pivoting,
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fully asynchronous approach with overlap of computation and communication,
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distributed dynamic scheduling of the computational tasks to allow for a good load balance in the presence of unexpected dynamic pivoting or in multi-user environments.
Mumps is currently used by more than 1000 academic and industrial users, from a wide range of application fields (see Section 4.1 ). Notice that the Mumps users include:
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students and academic users from all over the world;
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various developers of finite element software;
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companies such as Boeing, EADS, EDF, Free Field Technologies, or Samtech.
The latest release is Mumps 4.9.2, available since November 2009 (see http://graal.ens-lyon.fr/MUMPS/ ). The most recent features available are: a parallel analysis phase based on the parallel graph partitioning tools pt-scotch or parmetis, the use of 64-bit integers to address large memories, improved performance and memory usage.
