I'm attempting to solve a non-symmetric discretization of a 3D Poisson problem. The problem is singular. I've attached the results of KSPView from runs with ML and GAMG. When I run ML, I get convergence in 30 iterations. When I attempt to use the same settings with GAMG, I'm not getting convergence at all. The two things I notice are:
1. GAMG is using KSPType preonly, even though I've set it to be Richardson in my command line options. 2. ML only coarsens down to 4 rows while GAMG coarsens to 2. My problem is singular, and whenever I try to use LU, I get zero pivot problems. To mitigate this, I've been using Richardson with SOR on the coarse matrix. Could the smaller coarse grid size of GAMG be causing problems with SOR. If so, is there a way to put a lower limit on the coarse grid size? John On Thu, Mar 29, 2012 at 11:03 AM, Jed Brown <jedbrown at mcs.anl.gov> wrote: > On Thu, Mar 29, 2012 at 09:18, John Mousel <john.mousel at gmail.com> wrote: > >> [0]PETSC ERROR: Error in external library! >> [0]PETSC ERROR: Cannot disable floating point exceptions! >> > > Looks like something is strange with your environment because fesetenv() > is returning an error. I have disabled the call if the trap mode is not > changing. > > http://petsc.cs.iit.edu/petsc/petsc-dev/rev/352b4c19e451 > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20120329/5bd7defa/attachment.htm> -------------- next part -------------- [0]PCSetFromOptions_GAMG threshold set 1.000000e-02 [0]PCSetUp_GAMG level 0 N=556240, n data rows=1, n data cols=1, nnz/row (ave)=27, np=4 [0]PCGAMGFilterGraph 65.8687% nnz after filtering, with threshold 0.01, 27.0672 nnz ave. [0]maxIndSetAgg removed 0 of 556240 vertices. (0 local) 20114 selected. [0]PCGAMGProlongator_AGG New grid 20114 nodes PCGAMGOptprol_AGG smooth P0: max eigen=1.925528e+00 min=3.616018e-02 PC=jacobi [0]PCSetUp_GAMG 1) N=20114, n data cols=1, nnz/row (ave)=65, 4 active pes [0]PCGAMGFilterGraph 31.9285% nnz after filtering, with threshold 0.01, 65.3544 nnz ave. [0]maxIndSetAgg removed 0 of 20114 vertices. (0 local) 443 selected. [0]PCGAMGProlongator_AGG New grid 443 nodes PCGAMGOptprol_AGG smooth P0: max eigen=3.782372e+00 min=1.065309e-01 PC=jacobi [0]PCSetUp_GAMG 2) N=443, n data cols=1, nnz/row (ave)=113, 4 active pes [0]PCGAMGFilterGraph 11.1902% nnz after filtering, with threshold 0.01, 113.813 nnz ave. [0]maxIndSetAgg removed 0 of 443 vertices. (0 local) 20 selected. [0]PCGAMGProlongator_AGG New grid 20 nodes PCGAMGOptprol_AGG smooth P0: max eigen=2.141505e+00 min=5.132666e-03 PC=jacobi [0]createLevel aggregate processors: npe: 4 --> 1, neq=20 [0]PCSetUp_GAMG 3) N=20, n data cols=1, nnz/row (ave)=20, 1 active pes [0]PCGAMGFilterGraph 45% nnz after filtering, with threshold 0.01, 20 nnz ave. [0]maxIndSetAgg removed 0 of 20 vertices. (0 local) 2 selected. [0]PCGAMGProlongator_AGG New grid 2 nodes PCGAMGOptprol_AGG smooth P0: max eigen=1.444685e+00 min=9.769929e-05 PC=jacobi [0]PCSetUp_GAMG 4) N=2, n data cols=1, nnz/row (ave)=2, 1 active pes [0]PCSetUp_GAMG 5 levels, grid complexity = 1.09069 Residual norms for pres_ solve. 0 KSP preconditioned resid norm 1.653389026762e+05 true resid norm 1.643826511377e+01 ||r(i)||/||b|| 1.000000000000e+00 2 KSP preconditioned resid norm 3.498722572696e+04 true resid norm 1.676304035805e+01 ||r(i)||/||b|| 1.019757270128e+00 4 KSP preconditioned resid norm 3.466542979714e+04 true resid norm 1.682142736387e+01 ||r(i)||/||b|| 1.023309165988e+00 6 KSP preconditioned resid norm 3.544823492105e+04 true resid norm 2.096113365180e+01 ||r(i)||/||b|| 1.275142693388e+00 8 KSP preconditioned resid norm 3.830052737912e+04 true resid norm 4.734563796599e+01 ||r(i)||/||b|| 2.880208929489e+00 10 KSP preconditioned resid norm 4.928240285009e+04 true resid norm 1.505114395192e+02 ||r(i)||/||b|| 9.156163285936e+00 12 KSP preconditioned resid norm 2.692615589856e+04 true resid norm 1.610600319827e+02 ||r(i)||/||b|| 9.797872881841e+00 14 KSP preconditioned resid norm 3.258672961867e+04 true resid norm 3.930018988644e+01 ||r(i)||/||b|| 2.390774793717e+00 16 KSP preconditioned resid norm 5.254695737537e+04 true resid norm 3.184054936988e+02 ||r(i)||/||b|| 1.936977482083e+01 18 KSP preconditioned resid norm 4.664982713877e+04 true resid norm 2.267717910337e+02 ||r(i)||/||b|| 1.379536036584e+01 20 KSP preconditioned resid norm 3.556402200695e+04 true resid norm 3.209651885839e+01 ||r(i)||/||b|| 1.952549045550e+00 22 KSP preconditioned resid norm 3.751970755236e+04 true resid norm 6.277578808422e+01 ||r(i)||/||b|| 3.818881594241e+00 24 KSP preconditioned resid norm 3.528015422621e+04 true resid norm 2.472314669019e+01 ||r(i)||/||b|| 1.503999754176e+00 26 KSP preconditioned resid norm 3.520149611893e+04 true resid norm 2.349210422028e+01 ||r(i)||/||b|| 1.429110922454e+00 28 KSP preconditioned resid norm 3.541077679608e+04 true resid norm 2.187432271791e+01 ||r(i)||/||b|| 1.330695335944e+00 30 KSP preconditioned resid norm 3.517654266134e+04 true resid norm 2.171356997182e+01 ||r(i)||/||b|| 1.320916156391e+00 32 KSP preconditioned resid norm 3.515900089315e+04 true resid norm 2.158840469643e+01 ||r(i)||/||b|| 1.313301893297e+00 34 KSP preconditioned resid norm 3.559564844912e+04 true resid norm 2.273499576040e+01 ||r(i)||/||b|| 1.383053236035e+00 36 KSP preconditioned resid norm 3.558002879717e+04 true resid norm 2.230901057983e+01 ||r(i)||/||b|| 1.357138994013e+00 38 KSP preconditioned resid norm 3.536033027489e+04 true resid norm 2.255313539785e+01 ||r(i)||/||b|| 1.371990002702e+00 40 KSP preconditioned resid norm 3.530445288118e+04 true resid norm 2.222344798566e+01 ||r(i)||/||b|| 1.351933907371e+00 42 KSP preconditioned resid norm 3.531238381899e+04 true resid norm 2.203611003220e+01 ||r(i)||/||b|| 1.340537452078e+00 44 KSP preconditioned resid norm 3.526814846743e+04 true resid norm 2.162375692510e+01 ||r(i)||/||b|| 1.315452499120e+00 46 KSP preconditioned resid norm 3.549420786877e+04 true resid norm 2.658362282001e+01 ||r(i)||/||b|| 1.617179345632e+00 48 KSP preconditioned resid norm 3.475902657029e+04 true resid norm 6.863778415755e+01 ||r(i)||/||b|| 4.175488330582e+00 50 KSP preconditioned resid norm 3.455004242441e+04 true resid norm 8.709937353956e+01 ||r(i)||/||b|| 5.298574571997e+00 52 KSP preconditioned resid norm 3.397528825543e+04 true resid norm 1.124159495041e+02 ||r(i)||/||b|| 6.838674806984e+00 54 KSP preconditioned resid norm 3.312054456379e+04 true resid norm 1.290515134210e+02 ||r(i)||/||b|| 7.850677217321e+00 56 KSP preconditioned resid norm 3.451647821637e+04 true resid norm 2.295572351071e+01 ||r(i)||/||b|| 1.396480915221e+00 58 KSP preconditioned resid norm 3.415274707483e+04 true resid norm 1.478357632082e+02 ||r(i)||/||b|| 8.993392075441e+00 60 KSP preconditioned resid norm 3.301948214819e+04 true resid norm 1.684691863247e+02 ||r(i)||/||b|| 1.024859893418e+01 62 KSP preconditioned resid norm 3.312565770380e+04 true resid norm 1.525060310355e+02 ||r(i)||/||b|| 9.277501608592e+00 64 KSP preconditioned resid norm 3.185347314326e+04 true resid norm 1.829054885160e+02 ||r(i)||/||b|| 1.112681218183e+01 66 KSP preconditioned resid norm 3.171608219114e+04 true resid norm 1.875039031777e+02 ||r(i)||/||b|| 1.140655062319e+01 68 KSP preconditioned resid norm 3.171847298154e+04 true resid norm 1.880370116219e+02 ||r(i)||/||b|| 1.143898156652e+01 70 KSP preconditioned resid norm 3.178619322639e+04 true resid norm 1.860704776770e+02 ||r(i)||/||b|| 1.131935008890e+01 72 KSP preconditioned resid norm 3.184456847066e+04 true resid norm 1.852753590050e+02 ||r(i)||/||b|| 1.127098010177e+01 74 KSP preconditioned resid norm 3.189769214425e+04 true resid norm 1.842324138668e+02 ||r(i)||/||b|| 1.120753392111e+01 76 KSP preconditioned resid norm 3.199081602250e+04 true resid norm 1.822782258561e+02 ||r(i)||/||b|| 1.108865349199e+01 78 KSP preconditioned resid norm 3.102476484074e+04 true resid norm 2.097078712241e+02 ||r(i)||/||b|| 1.275729949436e+01 80 KSP preconditioned resid norm 3.065784272235e+04 true resid norm 2.065139379058e+02 ||r(i)||/||b|| 1.256300080796e+01 82 KSP preconditioned resid norm 2.394546049264e+04 true resid norm 4.274889221658e+02 ||r(i)||/||b|| 2.600572014182e+01 84 KSP preconditioned resid norm 5.540308447940e+04 true resid norm 2.519566526625e+02 ||r(i)||/||b|| 1.532744793436e+01 86 KSP preconditioned resid norm 8.474143362887e+05 true resid norm 1.261372272928e+04 ||r(i)||/||b|| 7.673390495884e+02 88 KSP preconditioned resid norm 1.848633122514e+06 true resid norm 2.777035833045e+04 ||r(i)||/||b|| 1.689372822391e+03 90 KSP preconditioned resid norm 7.565704677060e+05 true resid norm 1.143785512560e+04 ||r(i)||/||b|| 6.958067074863e+02 92 KSP preconditioned resid norm 6.757814515708e+05 true resid norm 1.024954173515e+04 ||r(i)||/||b|| 6.235172424959e+02 94 KSP preconditioned resid norm 6.614703098041e+05 true resid norm 1.004656691097e+04 ||r(i)||/||b|| 6.111695389652e+02 96 KSP preconditioned resid norm 2.934757771515e+05 true resid norm 4.802602009791e+03 ||r(i)||/||b|| 2.921599071771e+02 98 KSP preconditioned resid norm 2.585058956777e+05 true resid norm 4.004734942226e+03 ||r(i)||/||b|| 2.436227250570e+02 100 KSP preconditioned resid norm 2.309935778893e+05 true resid norm 4.002669905640e+03 ||r(i)||/||b|| 2.434971013022e+02 102 KSP preconditioned resid norm 2.015988421948e+05 true resid norm 4.016332928729e+03 ||r(i)||/||b|| 2.443282731439e+02 104 KSP preconditioned resid norm 2.045801533779e+05 true resid norm 4.000349066110e+03 ||r(i)||/||b|| 2.433559161154e+02 106 KSP preconditioned resid norm 2.264469374791e+05 true resid norm 3.893162890422e+03 ||r(i)||/||b|| 2.368353876445e+02 108 KSP preconditioned resid norm 3.080238001769e+05 true resid norm 3.906970507584e+03 ||r(i)||/||b|| 2.376753556743e+02 110 KSP preconditioned resid norm 2.793144888698e+05 true resid norm 4.313926252234e+03 ||r(i)||/||b|| 2.624319672652e+02 112 KSP preconditioned resid norm 2.403158281465e+05 true resid norm 5.534097030480e+03 ||r(i)||/||b|| 3.366594340813e+02 114 KSP preconditioned resid norm 1.045230913669e+06 true resid norm 2.054226795354e+04 ||r(i)||/||b|| 1.249661555606e+03 116 KSP preconditioned resid norm 1.059410089666e+06 true resid norm 2.765007218808e+04 ||r(i)||/||b|| 1.682055374865e+03 118 KSP preconditioned resid norm 7.620229766528e+05 true resid norm 2.851741985732e+04 ||r(i)||/||b|| 1.734819316999e+03 Linear solve did not converge due to DIVERGED_ITS iterations 118 KSP Object:(pres_) 4 MPI processes type: bcgsl BCGSL: Ell = 2 BCGSL: Delta = 0 maximum iterations=120 tolerances: relative=1e-08, absolute=1e-50, divergence=10000 left preconditioning has attached null space using nonzero initial guess using PRECONDITIONED norm type for convergence test PC Object:(pres_) 4 MPI processes type: gamg MG: type is MULTIPLICATIVE, levels=5 cycles=v Cycles per PCApply=1 Using Galerkin computed coarse grid matrices Coarse grid solver -- level ------------------------------- KSP Object: (pres_mg_coarse_) 4 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: (pres_mg_coarse_) 4 MPI processes type: sor SOR: type = local_symmetric, iterations = 8, local iterations = 1, omega = 1 linear system matrix = precond matrix: Matrix Object: 4 MPI processes type: mpiaij rows=2, cols=2 total: nonzeros=4, allocated nonzeros=4 total number of mallocs used during MatSetValues calls =0 using I-node (on process 0) routines: found 1 nodes, limit used is 5 Down solver (pre-smoother) on level 1 ------------------------------- KSP Object: (pres_mg_levels_1_) 4 MPI processes type: richardson Richardson: damping factor=1 maximum iterations=1 tolerances: relative=1e-05, absolute=1e-50, divergence=10000 left preconditioning using nonzero initial guess using NONE norm type for convergence test PC Object: (pres_mg_levels_1_) 4 MPI processes type: sor SOR: type = local_symmetric, iterations = 1, local iterations = 1, omega = 1 linear system matrix = precond matrix: Matrix Object: 4 MPI processes type: mpiaij rows=20, cols=20 total: nonzeros=400, allocated nonzeros=400 total number of mallocs used during MatSetValues calls =0 using I-node (on process 0) routines: found 4 nodes, limit used is 5 Up solver (post-smoother) same as down solver (pre-smoother) Down solver (pre-smoother) on level 2 ------------------------------- KSP Object: (pres_mg_levels_2_) 4 MPI processes type: richardson Richardson: damping factor=1 maximum iterations=1 tolerances: relative=1e-05, absolute=1e-50, divergence=10000 left preconditioning using nonzero initial guess using NONE norm type for convergence test PC Object: (pres_mg_levels_2_) 4 MPI processes type: sor SOR: type = local_symmetric, iterations = 1, local iterations = 1, omega = 1 linear system matrix = precond matrix: Matrix Object: 4 MPI processes type: mpiaij rows=443, cols=443 total: nonzeros=50419, allocated nonzeros=50419 total number of mallocs used during MatSetValues calls =0 not using I-node (on process 0) routines Up solver (post-smoother) same as down solver (pre-smoother) Down solver (pre-smoother) on level 3 ------------------------------- KSP Object: (pres_mg_levels_3_) 4 MPI processes type: richardson Richardson: damping factor=1 maximum iterations=1 tolerances: relative=1e-05, absolute=1e-50, divergence=10000 left preconditioning using nonzero initial guess using NONE norm type for convergence test PC Object: (pres_mg_levels_3_) 4 MPI processes type: sor SOR: type = local_symmetric, iterations = 1, local iterations = 1, omega = 1 linear system matrix = precond matrix: Matrix Object: 4 MPI processes type: mpiaij rows=20114, cols=20114 total: nonzeros=1314538, allocated nonzeros=1314538 total number of mallocs used during MatSetValues calls =0 not using I-node (on process 0) routines Up solver (post-smoother) same as down solver (pre-smoother) Down solver (pre-smoother) on level 4 ------------------------------- KSP Object: (pres_mg_levels_4_) 4 MPI processes type: richardson Richardson: damping factor=1 maximum iterations=1 tolerances: relative=1e-05, absolute=1e-50, divergence=10000 left preconditioning has attached null space using nonzero initial guess using NONE norm type for convergence test PC Object: (pres_mg_levels_4_) 4 MPI processes type: sor SOR: type = local_symmetric, iterations = 1, local iterations = 1, omega = 1 linear system matrix = precond matrix: Matrix Object: 4 MPI processes type: mpiaij rows=556240, cols=556240 total: nonzeros=15055870, allocated nonzeros=28055391 total number of mallocs used during MatSetValues calls =0 not using I-node (on process 0) routines Up solver (post-smoother) same as down solver (pre-smoother) linear system matrix = precond matrix: Matrix Object: 4 MPI processes type: mpiaij rows=556240, cols=556240 total: nonzeros=15055870, allocated nonzeros=28055391 total number of mallocs used during MatSetValues calls =0 not using I-node (on process 0) routines -------------- next part -------------- Residual norms for pres_ solve. 0 KSP preconditioned resid norm 2.993219493794e+03 true resid norm 1.643826511377e+01 ||r(i)||/||b|| 1.000000000000e+00 2 KSP preconditioned resid norm 4.012627047075e+03 true resid norm 2.722662316913e+02 ||r(i)||/||b|| 1.656295416864e+01 4 KSP preconditioned resid norm 7.152372463858e+02 true resid norm 3.245016507811e+01 ||r(i)||/||b|| 1.974062643078e+00 6 KSP preconditioned resid norm 2.615419780458e+02 true resid norm 2.745979195842e+01 ||r(i)||/||b|| 1.670479930112e+00 8 KSP preconditioned resid norm 1.626445578620e+02 true resid norm 8.455143190817e+00 ||r(i)||/||b|| 5.143573930885e-01 10 KSP preconditioned resid norm 3.412604554263e+01 true resid norm 6.517443353179e-01 ||r(i)||/||b|| 3.964800000530e-02 12 KSP preconditioned resid norm 4.448092876396e+01 true resid norm 2.990775751163e+00 ||r(i)||/||b|| 1.819398659448e-01 14 KSP preconditioned resid norm 1.003757428948e+00 true resid norm 2.495627994699e-01 ||r(i)||/||b|| 1.518182105853e-02 16 KSP preconditioned resid norm 6.831960905152e-01 true resid norm 2.110987118511e-02 ||r(i)||/||b|| 1.284190943449e-03 18 KSP preconditioned resid norm 8.821616336254e-02 true resid norm 1.421049860455e-02 ||r(i)||/||b|| 8.644767867046e-04 20 KSP preconditioned resid norm 2.018914933890e-02 true resid norm 1.749749201962e-03 ||r(i)||/||b|| 1.064436660349e-04 22 KSP preconditioned resid norm 2.149723645607e-02 true resid norm 7.137329046115e-04 ||r(i)||/||b|| 4.341899219119e-05 24 KSP preconditioned resid norm 1.085565650332e-03 true resid norm 9.250592958305e-05 ||r(i)||/||b|| 5.627475219728e-06 26 KSP preconditioned resid norm 5.850921166024e-04 true resid norm 3.554584676434e-05 ||r(i)||/||b|| 2.162384322088e-06 28 KSP preconditioned resid norm 2.636412182917e-04 true resid norm 8.740872361198e-06 ||r(i)||/||b|| 5.317393472305e-07 30 KSP preconditioned resid norm 8.051486995446e-06 true resid norm 5.329776180424e-06 ||r(i)||/||b|| 3.242298468565e-07 KSP Object:(pres_) 4 MPI processes type: bcgsl BCGSL: Ell = 2 BCGSL: Delta = 0 maximum iterations=5000 tolerances: relative=1e-08, absolute=1e-50, divergence=10000 left preconditioning has attached null space using nonzero initial guess using PRECONDITIONED norm type for convergence test PC Object:(pres_) 4 MPI processes type: ml MG: type is MULTIPLICATIVE, levels=6 cycles=v Cycles per PCApply=1 Using Galerkin computed coarse grid matrices Coarse grid solver -- level ------------------------------- KSP Object: (pres_mg_coarse_) 4 MPI processes type: richardson Richardson: damping factor=1 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: (pres_mg_coarse_) 4 MPI processes type: sor SOR: type = local_symmetric, iterations = 8, local iterations = 1, omega = 1 linear system matrix = precond matrix: Matrix Object: 4 MPI processes type: mpiaij rows=4, cols=4 total: nonzeros=16, allocated nonzeros=16 total number of mallocs used during MatSetValues calls =0 not using I-node (on process 0) routines Down solver (pre-smoother) on level 1 ------------------------------- KSP Object: (pres_mg_levels_1_) 4 MPI processes type: richardson Richardson: damping factor=1 maximum iterations=1 tolerances: relative=1e-05, absolute=1e-50, divergence=10000 left preconditioning using nonzero initial guess using PRECONDITIONED norm type for convergence test PC Object: (pres_mg_levels_1_) 4 MPI processes type: sor SOR: type = local_symmetric, iterations = 1, local iterations = 1, omega = 1 linear system matrix = precond matrix: Matrix Object: 4 MPI processes type: mpiaij rows=23, cols=23 total: nonzeros=481, allocated nonzeros=481 total number of mallocs used during MatSetValues calls =0 using I-node (on process 0) routines: found 2 nodes, limit used is 5 Up solver (post-smoother) same as down solver (pre-smoother) Down solver (pre-smoother) on level 2 ------------------------------- KSP Object: (pres_mg_levels_2_) 4 MPI processes type: richardson Richardson: damping factor=1 maximum iterations=1 tolerances: relative=1e-05, absolute=1e-50, divergence=10000 left preconditioning using nonzero initial guess using PRECONDITIONED norm type for convergence test PC Object: (pres_mg_levels_2_) 4 MPI processes type: sor SOR: type = local_symmetric, iterations = 1, local iterations = 1, omega = 1 linear system matrix = precond matrix: Matrix Object: 4 MPI processes type: mpiaij rows=204, cols=204 total: nonzeros=19040, allocated nonzeros=19040 total number of mallocs used during MatSetValues calls =0 using I-node (on process 0) routines: found 37 nodes, limit used is 5 Up solver (post-smoother) same as down solver (pre-smoother) Down solver (pre-smoother) on level 3 ------------------------------- KSP Object: (pres_mg_levels_3_) 4 MPI processes type: richardson Richardson: damping factor=1 maximum iterations=1 tolerances: relative=1e-05, absolute=1e-50, divergence=10000 left preconditioning using nonzero initial guess using PRECONDITIONED norm type for convergence test PC Object: (pres_mg_levels_3_) 4 MPI processes type: sor SOR: type = local_symmetric, iterations = 1, local iterations = 1, omega = 1 linear system matrix = precond matrix: Matrix Object: 4 MPI processes type: mpiaij rows=2704, cols=2704 total: nonzeros=277205, allocated nonzeros=277205 total number of mallocs used during MatSetValues calls =0 not using I-node (on process 0) routines Up solver (post-smoother) same as down solver (pre-smoother) Down solver (pre-smoother) on level 4 ------------------------------- KSP Object: (pres_mg_levels_4_) 4 MPI processes type: richardson Richardson: damping factor=1 maximum iterations=1 tolerances: relative=1e-05, absolute=1e-50, divergence=10000 left preconditioning using nonzero initial guess using PRECONDITIONED norm type for convergence test PC Object: (pres_mg_levels_4_) 4 MPI processes type: sor SOR: type = local_symmetric, iterations = 1, local iterations = 1, omega = 1 linear system matrix = precond matrix: Matrix Object: 4 MPI processes type: mpiaij rows=52276, cols=52276 total: nonzeros=5628023, allocated nonzeros=5628023 total number of mallocs used during MatSetValues calls =0 not using I-node (on process 0) routines Up solver (post-smoother) same as down solver (pre-smoother) Down solver (pre-smoother) on level 5 ------------------------------- KSP Object: (pres_mg_levels_5_) 4 MPI processes type: richardson Richardson: damping factor=1 maximum iterations=1 tolerances: relative=1e-05, absolute=1e-50, divergence=10000 left preconditioning has attached null space using nonzero initial guess using PRECONDITIONED norm type for convergence test PC Object: (pres_mg_levels_5_) 4 MPI processes type: sor SOR: type = local_symmetric, iterations = 1, local iterations = 1, omega = 1 linear system matrix = precond matrix: Matrix Object: 4 MPI processes type: mpiaij rows=556240, cols=556240 total: nonzeros=15055870, allocated nonzeros=28055391 total number of mallocs used during MatSetValues calls =0 not using I-node (on process 0) routines Up solver (post-smoother) same as down solver (pre-smoother) linear system matrix = precond matrix: Matrix Object: 4 MPI processes type: mpiaij rows=556240, cols=556240 total: nonzeros=15055870, allocated nonzeros=28055391 total number of mallocs used during MatSetValues calls =0 not using I-node (on process 0) routines
