Numerical factorization is always parallel (based on number of MPI tasks and OMP_NUM_THREADS you set), the issue here is only related to symbolic factorization (figuring out the nonzero pattern in the LU factors). Default setting is to use sequential symbolic factorization, precisely due to the ParMETIS bugs. (The parallel symbolic factorization needs ParMETIS ordering.)
Question for PETSc developers -- Is PT-Scotch an installation option? I can try to use PT_Scotch together with parallel symbolic factorization, which should be more stable than ParMETIS. Sherry On Tue, May 22, 2018 at 9:00 AM, Eric Chamberland < [email protected]> wrote: > And I will add a question: > > Shouldn't there be an automatic switch to parallele factorisation when > num. of process is greater than 1 ? > > Eric > > > On 22/05/18 11:55 AM, Eric Chamberland wrote: > >> Exactly: this bug shows up when I activate the parallel symbolic >> factorisation, otherwise I do not have it. >> >
