Try -pc_gamg_reuse_interpolation 0. I thought this was disabled by default, but I see pc_gamg->reuse_prol = PETSC_TRUE in the code.
Blaise Bourdin <bour...@mcmaster.ca> writes: > On Mar 24, 2023, at 3:21 PM, Mark Adams <mfad...@lbl.gov> wrote: > > * Do you set: > > PetscCall(MatSetOption(Amat, MAT_SPD, PETSC_TRUE)); > > PetscCall(MatSetOption(Amat, MAT_SPD_ETERNAL, PETSC_TRUE)); > > Yes > > Do that to get CG Eigen estimates. Outright failure is usually caused by a > bad Eigen estimate. > -pc_gamg_esteig_ksp_monitor_singular_value > Will print out the estimates as its iterating. You can look at that to check > that the max has converged. > > I just did, and something is off: > I do multiple calls to SNESSolve (staggered scheme for phase-field fracture), > but only get informations on the first solve (which is > not the one failing, of course) > Here is what I get: > Residual norms for Displacement_pc_gamg_esteig_ solve. > 0 KSP Residual norm 7.636421712860e+01 % max 1.000000000000e+00 min > 1.000000000000e+00 max/min > 1.000000000000e+00 > 1 KSP Residual norm 3.402024867977e+01 % max 1.114319928921e+00 min > 1.114319928921e+00 max/min > 1.000000000000e+00 > 2 KSP Residual norm 2.124815079671e+01 % max 1.501143586520e+00 min > 5.739351119078e-01 max/min > 2.615528402732e+00 > 3 KSP Residual norm 1.581785698912e+01 % max 1.644351137983e+00 min > 3.263683482596e-01 max/min > 5.038329074347e+00 > 4 KSP Residual norm 1.254871990315e+01 % max 1.714668863819e+00 min > 2.044075812142e-01 max/min > 8.388479789416e+00 > 5 KSP Residual norm 1.051198229090e+01 % max 1.760078533063e+00 min > 1.409327403114e-01 max/min > 1.248878386367e+01 > 6 KSP Residual norm 9.061658306086e+00 % max 1.792995287686e+00 min > 1.023484740555e-01 max/min > 1.751853463603e+01 > 7 KSP Residual norm 8.015529297567e+00 % max 1.821497535985e+00 min > 7.818018001928e-02 max/min > 2.329871248104e+01 > 8 KSP Residual norm 7.201063258957e+00 % max 1.855140071935e+00 min > 6.178572472468e-02 max/min > 3.002538337458e+01 > 9 KSP Residual norm 6.548491711695e+00 % max 1.903578294573e+00 min > 5.008612895206e-02 max/min > 3.800609738466e+01 > 10 KSP Residual norm 6.002109992255e+00 % max 1.961356890125e+00 min > 4.130572033722e-02 max/min > 4.748390475004e+01 > Residual norms for Displacement_pc_gamg_esteig_ solve. > 0 KSP Residual norm 2.373573910237e+02 % max 1.000000000000e+00 min > 1.000000000000e+00 max/min > 1.000000000000e+00 > 1 KSP Residual norm 8.845061415709e+01 % max 1.081192207576e+00 min > 1.081192207576e+00 max/min > 1.000000000000e+00 > 2 KSP Residual norm 5.607525485152e+01 % max 1.345947059840e+00 min > 5.768825326129e-01 max/min > 2.333138869267e+00 > 3 KSP Residual norm 4.123522550864e+01 % max 1.481153523075e+00 min > 3.070603564913e-01 max/min > 4.823655974348e+00 > 4 KSP Residual norm 3.345765664017e+01 % max 1.551374710727e+00 min > 1.953487694959e-01 max/min > 7.941563771968e+00 > 5 KSP Residual norm 2.859712984893e+01 % max 1.604588395452e+00 min > 1.313871480574e-01 max/min > 1.221267391199e+01 > 6 KSP Residual norm 2.525636054248e+01 % max 1.650487481750e+00 min > 9.322735730688e-02 max/min > 1.770389646804e+01 > 7 KSP Residual norm 2.270711391451e+01 % max 1.697243639599e+00 min > 6.945419058256e-02 max/min > 2.443687883140e+01 > 8 KSP Residual norm 2.074739485241e+01 % max 1.737293728907e+00 min > 5.319942519758e-02 max/min > 3.265624999621e+01 > 9 KSP Residual norm 1.912808268870e+01 % max 1.771708608618e+00 min > 4.229776586667e-02 max/min > 4.188657656771e+01 > 10 KSP Residual norm 1.787394414641e+01 % max 1.802834420843e+00 min > 3.460455235448e-02 max/min > 5.209818645753e+01 > Residual norms for Displacement_pc_gamg_esteig_ solve. > 0 KSP Residual norm 1.361990679391e+03 % max 1.000000000000e+00 min > 1.000000000000e+00 max/min > 1.000000000000e+00 > 1 KSP Residual norm 5.377188333825e+02 % max 1.086812916769e+00 min > 1.086812916769e+00 max/min > 1.000000000000e+00 > 2 KSP Residual norm 2.819790765047e+02 % max 1.474233179517e+00 min > 6.475176340551e-01 max/min > 2.276745994212e+00 > 3 KSP Residual norm 1.856720658591e+02 % max 1.646049713883e+00 min > 4.391851040105e-01 max/min > 3.747963441500e+00 > 4 KSP Residual norm 1.446507859917e+02 % max 1.760403013135e+00 min > 2.972886103795e-01 max/min > 5.921528614526e+00 > 5 KSP Residual norm 1.212491636433e+02 % max 1.839250080524e+00 min > 1.921591413785e-01 max/min > 9.571494061277e+00 > 6 KSP Residual norm 1.052783637696e+02 % max 1.887062042760e+00 min > 1.275920366984e-01 max/min > 1.478981048966e+01 > 7 KSP Residual norm 9.230292625762e+01 % max 1.917891358356e+00 min > 8.853577120467e-02 max/min > 2.166233300122e+01 > 8 KSP Residual norm 8.262607594297e+01 % max 1.935857204308e+00 min > 6.706949937710e-02 max/min > 2.886345093206e+01 > 9 KSP Residual norm 7.616474911000e+01 % max 1.946323901431e+00 min > 5.354310733090e-02 max/min > 3.635059671458e+01 > 10 KSP Residual norm 7.138356892221e+01 % max 1.954382723686e+00 min > 4.367661484659e-02 max/min > 4.474666204216e+01 > Residual norms for Displacement_pc_gamg_esteig_ solve. > 0 KSP Residual norm 3.702300162209e+03 % max 1.000000000000e+00 min > 1.000000000000e+00 max/min > 1.000000000000e+00 > 1 KSP Residual norm 1.255008322497e+03 % max 9.938792139169e-01 min > 9.938792139169e-01 max/min > 1.000000000000e+00 > 2 KSP Residual norm 6.727201181977e+02 % max 1.297844907149e+00 min > 6.478406586220e-01 max/min > 2.003339694532e+00 > 3 KSP Residual norm 5.218419298230e+02 % max 1.435817121668e+00 min > 3.868381643086e-01 max/min > 3.711673909512e+00 > 4 KSP Residual norm 4.562548407646e+02 % max 1.507841675332e+00 min > 1.835807205925e-01 max/min > 8.213507771759e+00 > 5 KSP Residual norm 3.829651184063e+02 % max 1.544809112105e+00 min > 9.645201420491e-02 max/min > 1.601634890510e+01 > 6 KSP Residual norm 2.858162778588e+02 % max 1.571662611009e+00 min > 6.326714268751e-02 max/min > 2.484168786904e+01 > 7 KSP Residual norm 2.074805889949e+02 % max 1.587767457742e+00 min > 5.145942909400e-02 max/min > 3.085474296347e+01 > 8 KSP Residual norm 1.566220417755e+02 % max 1.597548616381e+00 min > 4.650092979233e-02 max/min > 3.435519727274e+01 > 9 KSP Residual norm 1.157894309297e+02 % max 1.603863600136e+00 min > 4.344076378399e-02 max/min > 3.692070443585e+01 > 10 KSP Residual norm 8.447209442299e+01 % max 1.608204129656e+00 min > 4.123402730882e-02 max/min > 3.900186895670e+01 > Linear Displacement_ solve converged due to CONVERGED_RTOL iterations 14 > > * -pc_gamg_aggressive_coarsening 0 > > will slow coarsening as well as threshold. > > That did not help > > * you can run with '-info :pc' and send me the output (grep on GAMG) > > Let’s try to figure out if the fact that > -pc_gamg_esteig_ksp_monitor_singular_value is an indication of a problem > first. > > Blaise > > — > Canada Research Chair in Mathematical and Computational Aspects of Solid > Mechanics (Tier 1) > Professor, Department of Mathematics & Statistics > Hamilton Hall room 409A, McMaster University > 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada > https://www.math.mcmaster.ca/bourdin | +1 (905) 525 9140 ext. 27243
