Hi, There is a heat conduction problem. When superlu_dist is used as a preconditioner, we have random results from different runs. Is there a random algorithm in superlu_dist? If we use ASM or MUMPS as the preconditioner, we then don't have this issue.
run 1: 0 Nonlinear |R| = 9.447423e+03 0 Linear |R| = 9.447423e+03 1 Linear |R| = 1.013384e-02 2 Linear |R| = 4.020995e-08 1 Nonlinear |R| = 1.404678e-02 0 Linear |R| = 1.404678e-02 1 Linear |R| = 5.104757e-08 2 Linear |R| = 7.699637e-14 2 Nonlinear |R| = 5.106418e-08 run 2: 0 Nonlinear |R| = 9.447423e+03 0 Linear |R| = 9.447423e+03 1 Linear |R| = 1.013384e-02 2 Linear |R| = 4.020995e-08 1 Nonlinear |R| = 1.404678e-02 0 Linear |R| = 1.404678e-02 1 Linear |R| = 5.109913e-08 2 Linear |R| = 7.189091e-14 2 Nonlinear |R| = 5.111591e-08 run 3: 0 Nonlinear |R| = 9.447423e+03 0 Linear |R| = 9.447423e+03 1 Linear |R| = 1.013384e-02 2 Linear |R| = 4.020995e-08 1 Nonlinear |R| = 1.404678e-02 0 Linear |R| = 1.404678e-02 1 Linear |R| = 5.104942e-08 2 Linear |R| = 7.465572e-14 2 Nonlinear |R| = 5.106642e-08 run 4: 0 Nonlinear |R| = 9.447423e+03 0 Linear |R| = 9.447423e+03 1 Linear |R| = 1.013384e-02 2 Linear |R| = 4.020995e-08 1 Nonlinear |R| = 1.404678e-02 0 Linear |R| = 1.404678e-02 1 Linear |R| = 5.102730e-08 2 Linear |R| = 7.132220e-14 2 Nonlinear |R| = 5.104442e-08 Solver details: SNES Object: 8 MPI processes type: newtonls maximum iterations=15, maximum function evaluations=10000 tolerances: relative=1e-08, absolute=1e-11, solution=1e-50 total number of linear solver iterations=4 total number of function evaluations=7 norm schedule ALWAYS SNESLineSearch Object: 8 MPI processes type: basic maxstep=1.000000e+08, minlambda=1.000000e-12 tolerances: relative=1.000000e-08, absolute=1.000000e-15, lambda=1.000000e-08 maximum iterations=40 KSP Object: 8 MPI processes type: gmres restart=30, using Classical (unmodified) Gram-Schmidt Orthogonalization with no iterative refinement happy breakdown tolerance 1e-30 maximum iterations=100, initial guess is zero tolerances: relative=1e-06, absolute=1e-50, divergence=10000. right preconditioning using UNPRECONDITIONED norm type for convergence test PC Object: 8 MPI processes type: lu out-of-place factorization tolerance for zero pivot 2.22045e-14 matrix ordering: natural factor fill ratio given 0., needed 0. Factored matrix follows: Mat Object: 8 MPI processes type: superlu_dist rows=7925, cols=7925 package used to perform factorization: superlu_dist total: nonzeros=0, allocated nonzeros=0 total number of mallocs used during MatSetValues calls =0 SuperLU_DIST run parameters: Process grid nprow 4 x npcol 2 Equilibrate matrix TRUE Matrix input mode 1 Replace tiny pivots FALSE Use iterative refinement TRUE Processors in row 4 col partition 2 Row permutation LargeDiag Column permutation METIS_AT_PLUS_A Parallel symbolic factorization FALSE Repeated factorization SamePattern linear system matrix followed by preconditioner matrix: Mat Object: 8 MPI processes type: mffd rows=7925, cols=7925 Matrix-free approximation: err=1.49012e-08 (relative error in function evaluation) Using wp compute h routine Does not compute normU Mat Object: () 8 MPI processes type: mpiaij rows=7925, cols=7925 total: nonzeros=63587, allocated nonzeros=63865 total number of mallocs used during MatSetValues calls =0 not using I-node (on process 0) routines Fande,