Adaptive paging for a multifrontal solver

Abstract

In this paper, we present a new way to improve performance of the factorization of large sparse linear systems which cannot fit in memory. Instead of rewriting a large part of the code to implement an out-of-core algorithm with explicit I/O, we modify the paging mechanisms in such a way that I/O are transparent. This approach will be helpful to study the key points for getting performance with large problems on under sized memory machines with an explicit out-of-core scheme. The modification is done thanks to the MMUM&MMUSSEL software tool which allows the management of the paging activity at the application level. We designed a first paging polic that is well adapted for the parallel multifrontal solver MUMPS We present here a study and we give our preliminary results.