Layer-by-Layer Partitioning of Finite Element Meshes for Multicore Architectures

In this paper, we present new partitioning algorithms for unstructured meshes that prevent conflicts during parallel assembly of FEM matrices and vectors in shared memory. The algorithms use a criterion that determines if any two mesh cells are neighboring. This neighborhood criterion is used to partition the mesh into layers, which are then combined into blocks and assigned to different parallel processes/threads. The proposed partitioning algorithms are compared with the existing algorithms on quasi-structured and unstructured meshes by the number of potential conflicts and by the load imbalance.