Fine-Grained Parallel Incomplete LU Factorization

This paper presents a new fine-grained parallel algorithm for computing an incomplete LU factorization. All nonzeros in the incomplete factors can be computed in parallel and asynchronously, using one or more sweeps that iteratively improve the accuracy of the factorization. Unlike existing parallel algorithms, the new algorithm does not depend on reordering the matrix. Numerical tests show that very few sweeps are needed to construct a factorization that is an effective preconditioner.