[petsc-users] DIVERGED_PCSETUP_FAILED
Michele Rosso
mrosso at uci.edu
Wed Feb 10 20:21:31 CST 2016
Hi Matt,
the ksp_view output was an attachment to my previous email.
Here it is:
KSP Object: 1 MPI processes
type: cg
maximum iterations=10000
tolerances: relative=1e-08, absolute=1e-50, divergence=10000.
left preconditioning
using nonzero initial guess
using UNPRECONDITIONED norm type for convergence test
PC Object: 1 MPI processes
type: mg
MG: type is MULTIPLICATIVE, levels=4 cycles=v
Cycles per PCApply=1
Using Galerkin computed coarse grid matrices
Coarse grid solver -- level -------------------------------
KSP Object: (mg_coarse_) 1 MPI processes
type: preonly
maximum iterations=1, initial guess is zero
tolerances: relative=1e-05, absolute=1e-50, divergence=10000.
left preconditioning
using NONE norm type for convergence test
PC Object: (mg_coarse_) 1 MPI processes
type: lu
LU: out-of-place factorization
tolerance for zero pivot 2.22045e-14
using diagonal shift on blocks to prevent zero pivot [INBLOCKS]
matrix ordering: nd
factor fill ratio given 0., needed 0.
Factored matrix follows:
Mat Object: 1 MPI processes
type: seqaij
rows=16, cols=16
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 1 x npcol 1
Equilibrate matrix TRUE
Matrix input mode 0
Replace tiny pivots FALSE
Use iterative refinement FALSE
Processors in row 1 col partition 1
Row permutation LargeDiag
Column permutation METIS_AT_PLUS_A
Parallel symbolic factorization FALSE
Repeated factorization SamePattern
linear system matrix = precond matrix:
Mat Object: 1 MPI processes
type: seqaij
rows=16, cols=16
total: nonzeros=72, allocated nonzeros=72
total number of mallocs used during MatSetValues calls =0
not using I-node routines
Down solver (pre-smoother) on level 1 -------------------------------
KSP Object: (mg_levels_1_) 1 MPI processes
type: richardson
Richardson: damping factor=1.
maximum iterations=2
tolerances: relative=1e-05, absolute=1e-50, divergence=10000.
left preconditioning
using nonzero initial guess
using NONE norm type for convergence test
PC Object: (mg_levels_1_) 1 MPI processes
type: sor
SOR: type = local_symmetric, iterations = 1, local iterations =
1, omega = 1.
linear system matrix = precond matrix:
Mat Object: 1 MPI processes
type: seqaij
rows=64, cols=64
total: nonzeros=304, allocated nonzeros=304
total number of mallocs used during MatSetValues calls =0
not using I-node routines
Up solver (post-smoother) same as down solver (pre-smoother)
Down solver (pre-smoother) on level 2 -------------------------------
KSP Object: (mg_levels_2_) 1 MPI processes
type: richardson
Richardson: damping factor=1.
maximum iterations=2
tolerances: relative=1e-05, absolute=1e-50, divergence=10000.
left preconditioning
using nonzero initial guess
using NONE norm type for convergence test
PC Object: (mg_levels_2_) 1 MPI processes
type: sor
SOR: type = local_symmetric, iterations = 1, local iterations =
1, omega = 1.
linear system matrix = precond matrix:
Mat Object: 1 MPI processes
type: seqaij
rows=256, cols=256
total: nonzeros=1248, allocated nonzeros=1248
total number of mallocs used during MatSetValues calls =0
not using I-node routines
Up solver (post-smoother) same as down solver (pre-smoother)
Down solver (pre-smoother) on level 3 -------------------------------
KSP Object: (mg_levels_3_) 1 MPI processes
type: richardson
Richardson: damping factor=1.
maximum iterations=2
tolerances: relative=1e-05, absolute=1e-50, divergence=10000.
left preconditioning
using nonzero initial guess
using NONE norm type for convergence test
PC Object: (mg_levels_3_) 1 MPI processes
type: sor
SOR: type = local_symmetric, iterations = 1, local iterations =
1, omega = 1.
linear system matrix = precond matrix:
Mat Object: 1 MPI processes
type: seqaij
rows=1024, cols=1024
total: nonzeros=5056, allocated nonzeros=5056
total number of mallocs used during MatSetValues calls =0
has attached null space
not using I-node routines
Up solver (post-smoother) same as down solver (pre-smoother)
linear system matrix = precond matrix:
Mat Object: 1 MPI processes
type: seqaij
rows=1024, cols=1024
total: nonzeros=5056, allocated nonzeros=5056
total number of mallocs used during MatSetValues calls =0
has attached null space
not using I-node routines
Michele
On Wed, 2016-02-10 at 19:37 -0600, Matthew Knepley wrote:
> On Wed, Feb 10, 2016 at 7:33 PM, Michele Rosso <mrosso at uci.edu> wrote:
>
> Hi,
>
> I encountered the following error while solving a symmetric
> positive defined system:
>
> Linear solve did not converge due to DIVERGED_PCSETUP_FAILED
> iterations 0
> PCSETUP_FAILED due to SUBPC_ERROR
>
> This error appears only if I use the optimized version of
> both petsc and my code ( compiler: gfortran, flags: -O3 ).
> It is weird since I am solving a time-dependent problem and
> everything, i.e. results and convergence rate, are as expected
> until the above error shows up. If I run both petsc and my
> code in debug mode, everything goes smooth till the end of the
> simulation.
> However, if I reduce the ksp_rtol, even the debug run fails,
> after running as expected for a while, because of a
> KSP_DIVERGED_INDEFINITE_PC .
> The options I am using are:
>
> -ksp_type cg
> -ksp_norm_type unpreconditioned
> -ksp_rtol 1e-8
> -ksp_lag_norm
> -ksp_initial_guess_nonzero yes
> -pc_type mg
> -pc_mg_galerkin
> -pc_mg_levels 4
> -mg_levels_ksp_type richardson
> -mg_coarse_ksp_constant_null_space
> -mg_coarse_pc_type lu
> -mg_coarse_pc_factor_mat_solver_package superlu_dist
> -options_left
>
> I attached a copy of ksp_view. I am currently using
> petsc-master (last updated yesterday).
> I would appreciate any suggestion on this matter.
>
>
>
> I suspect you have a nonlinear PC. Can you send the output of
> -ksp_view?
>
>
> Matt
>
> Thanks,
> Michele
>
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> --
>
> What most experimenters take for granted before they begin their
> experiments is infinitely more interesting than any results to which
> their experiments lead.
> -- Norbert Wiener
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