Parallel computation of entries in A-1
Résumé
In this paper, we consider the computation in parallel of several entries of the inverse
of a large sparse matrix. We assume that the matrix has already been factorized by a direct method
and that the factors are distributed. Entries are efficiently computed by exploiting sparsity of the
right-hand sides and the solution vectors in the triangular solution phase. We demonstrate that in
this setting, parallelism and computational efficiency are two contrasting objectives. We develop an
efficient approach and show its efficiency on a general purpose parallel multifrontal solver.