On Aug 8, 2021, at 7:42 AM, Pierre Jolivet <pierre@joliv.et> wrote:

Hello,

I’d like to trigger an error if a linear solve does not converge due to DIVERGED_ITS.

Since this MR https://gitlab.com/petsc/petsc/-/merge_requests/1294, no error is triggered anymore if ksp->reason == KSP_DIVERGED_ITS.

This seems to be inconsistent with -snes_error_if_not_converged.

Is there a workaround? Shouldn’t this be clarified in the manual page?

Thank you,

Pierre

$ src/ksp/ksp/tutorials/ex1 -ksp_max_it 1 -ksp_converged_reason -ksp_error_if_not_converged && echo "No error"

Linear solve did not converge due to DIVERGED_ITS iterations 1

KSP Object: 1 MPI processes

  type: gmres

    restart=30, using Classical (unmodified) Gram-Schmidt Orthogonalization with no iterative refinement

    happy breakdown tolerance 1e-30

  maximum iterations=1, initial guess is zero

  tolerances:  relative=1e-05, absolute=1e-50, divergence=10000.

  left preconditioning

  using PRECONDITIONED norm type for convergence test

PC Object: 1 MPI processes

  type: jacobi

    type DIAGONAL

  linear system matrix = precond matrix:

  Mat Object: 1 MPI processes

    type: seqaij

    rows=10, cols=10

    total: nonzeros=28, allocated nonzeros=50

    total number of mallocs used during MatSetValues calls=0

      not using I-node routines

Norm of error 2.95296, Iterations 1

No error