KSP Object: 4 MPI processes type: gmres restart=30, using classical (unmodified) Gram-Schmidt orthogonalization with no iterative refinement happy breakdown tolerance=1e-30 maximum iterations=10000, initial guess is zero tolerances: relative=1e-05, absolute=1e-50, divergence=10000. left preconditioning using PRECONDITIONED norm type for convergence test PC Object: 4 MPI processes type: asm total subdomain blocks = 4, user-defined overlap restriction/interpolation type - RESTRICT Local solver information for first block is in the following KSP and PC objects on rank 0: Use -ksp_view ::ascii_info_detail to display information for all blocks KSP Object: (sub_) 1 MPI process type: preonly maximum iterations=10000, initial guess is zero tolerances: relative=1e-05, absolute=1e-50, divergence=10000. left preconditioning not checking for convergence PC Object: (sub_) 1 MPI process type: ilu out-of-place factorization 0 levels of fill tolerance for zero pivot 2.22045e-14 matrix ordering: natural factor fill ratio given 1., needed 1. Factored matrix: Mat Object: (sub_) 1 MPI process type: seqaij rows=32, cols=32 package used to perform factorization: petsc total: nonzeros=140, allocated nonzeros=140 not using I-node routines linear system matrix, which is also used to construct the preconditioner: Mat Object: (sub_) 1 MPI process type: seqaij rows=32, cols=32 total: nonzeros=140, allocated nonzeros=140 total number of mallocs used during MatSetValues calls=0 not using I-node routines linear system matrix, which is also used to construct the preconditioner: Mat Object: 4 MPI processes type: mpiaij rows=64, cols=64 total: nonzeros=288, allocated nonzeros=288 total number of mallocs used during MatSetValues calls=0 not using I-node (on process 0) routines Infinity norm of the error: 3.6538e-06