<div dir="ltr"><div><div>Barry,<br><br>I'm using petsc-dev that I cloned about 2 days ago after you pushed a change in VecSet.<br><br></div>There was no extra part of the error message, which confused me as well.<br><br>
</div>-options_left returns: <br><div>-pres_redistribute_gamg_type value: agg<br><br></div><div>John<br>
</div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Wed, Jul 23, 2014 at 4:11 PM, Barry Smith <span dir="ltr"><<a href="mailto:bsmith@mcs.anl.gov" target="_blank">bsmith@mcs.anl.gov</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div class=""><br>
On Jul 23, 2014, at 9:54 AM, John Mousel <<a href="mailto:john.mousel@gmail.com">john.mousel@gmail.com</a>> wrote:<br>
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> I'm getting an FPE in LAPACKgesvd of KSPComputeExtremeSingularValues_GMRES.<br>
<br>
</div> ierr = PetscFPTrapPush(PETSC_FP_TRAP_OFF);CHKERRQ(ierr);<br>
#if !defined(PETSC_USE_COMPLEX)<br>
PetscStackCallBLAS("LAPACKgesvd",LAPACKgesvd_("N","N",&bn,&bn,R,&bN,realpart,&sdummy,&idummy,&sdummy,&idummy,work,&lwork,&lierr));<br>
#else<br>
PetscStackCallBLAS("LAPACKgesvd",LAPACKgesvd_("N","N",&bn,&bn,R,&bN,realpart,&sdummy,&idummy,&sdummy,&idummy,work,&lwork,realpart+N,&lierr));<br>
#endif<br>
if (lierr) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_LIB,"Error in SVD Lapack routine %d",(int)lierr);<br>
ierr = PetscFPTrapPop();CHKERRQ(ierr);<br>
<br>
What version of PETSc are you using? In our current release we turn off the trapping for that routine but maybe yours is a system that cannot turn it off<br>
<div class=""><br>
> I'm not sure where this routine is required during the algorithm as I'm using BiCG + richardson/SOR on all multigrid levels.<br>
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</div> Good question. Yes it would normally not use the KSPComputeExtremeSingularValues_GMRES() Is there more error message that shows where the functions are called from?<br>
<div class=""><br>
> Also, even though I've set mg_coarse_ksp_type richardson, KSPView is showing that preonly is used on the coarsest level. Am I misunderstanding something about the options I'm using?<br>
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</div> They seem to be correct. If you run with -options_left does it indicate that option is never used?<br>
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Suggest upgrading to PETSc 3.5<br>
<span class="HOEnZb"><font color="#888888"><br>
Barry<br>
</font></span><div class="HOEnZb"><div class="h5"><br>
><br>
> -pres_ksp_type preonly -pres_pc_type redistribute -pres_redistribute_ksp_type bcgsl -pres_redistribute_pc_type gamg -pres_redistribute_pc_gamg_threshold 0.01 -pres_redistribute_mg_levels_ksp_type richardson -pres_redistribute_mg_levels_pc_type sor -pres_redistribute_mg_coarse_ksp_type richardson -pres_redistribute_mg_coarse_pc_type sor -pres_redistribute_mg_coarse_pc_sor_its 4 -pres_redistribute_pc_gamg_agg_nsmooths 1 -pres_redistribute_pc_gamg_sym_graph true -pres_redistribute_gamg_type agg -pres_ksp_view<br>
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> [8]PETSC ERROR: ------------------------------------------------------------------------<br>
> [8]PETSC ERROR: Caught signal number 8 FPE: Floating Point Exception,probably divide by zero<br>
> [8]PETSC ERROR: Try option -start_in_debugger or -on_error_attach_debugger<br>
> [8]PETSC ERROR: or see <a href="http://www.mcs.anl.gov/petsc/documentation/faq.html#valgrind[8]PETSC" target="_blank">http://www.mcs.anl.gov/petsc/documentation/faq.html#valgrind[8]PETSC</a> ERROR: or try <a href="http://valgrind.org" target="_blank">http://valgrind.org</a> on GNU/linux and Apple Mac OS X to find memory corruption errors<br>
> [40]PETSC ERROR: ------------------------------------------------------------------------<br>
> [40]PETSC ERROR: Caught signal number 8 FPE: Floating Point Exception,probably divide by zero<br>
> [40]PETSC ERROR: Try option -start_in_debugger or -on_error_attach_debugger<br>
> [40]PETSC ERROR: or see <a href="http://www.mcs.anl.gov/petsc/documentation/faq.html#valgrind[40]PETSC" target="_blank">http://www.mcs.anl.gov/petsc/documentation/faq.html#valgrind[40]PETSC</a> ERROR: or try <a href="http://valgrind.org" target="_blank">http://valgrind.org</a> on GNU/linux and Apple Mac OS X to find memory corruption errors<br>
> [40]PETSC ERROR: likely location of problem given in stack below<br>
> [40]PETSC ERROR: --------------------- Stack Frames ------------------------------------<br>
> [40]PETSC ERROR: Note: The EXACT line numbers in the stack are not available,<br>
> [40]PETSC ERROR: INSTEAD the line number of the start of the function<br>
> [40]PETSC ERROR: is given.<br>
> [40]PETSC ERROR: [40] LAPACKgesvd line 42 /Users/jmousel/SOFT/petsc/src/ksp/ksp/impls/gmres/gmreig.c<br>
> [40]PETSC ERROR: [40] KSPComputeExtremeSingularValues_GMRES line 24 /Users/jmousel/SOFT/petsc/src/ksp/ksp/impls/gmres/gmreig.c<br>
> [40]PETSC ERROR: [40] KSPComputeExtremeSingularValues line 51 /Users/jmousel/SOFT/petsc/src/ksp/ksp/interface/itfunc.c<br>
><br>
><br>
><br>
> KSP Object:proj_ksp(pres_) 96 MPI processes<br>
> type: preonly<br>
> maximum iterations=1000, initial guess is zero<br>
> tolerances: relative=1e-50, absolute=0.01, divergence=10000<br>
> left preconditioning<br>
> using NONE norm type for convergence test<br>
> PC Object:(pres_) 96 MPI processes<br>
> type: redistribute<br>
> Number rows eliminated 7115519 Percentage rows eliminated 44.1051<br>
> Redistribute preconditioner:<br>
> KSP Object: (pres_redistribute_) 96 MPI processes<br>
> type: bcgsl<br>
> BCGSL: Ell = 2<br>
> BCGSL: Delta = 0<br>
> maximum iterations=1000, initial guess is zero<br>
> tolerances: relative=1e-50, absolute=0.01, divergence=10000<br>
> left preconditioning<br>
> has attached null space<br>
> using PRECONDITIONED norm type for convergence test<br>
> PC Object: (pres_redistribute_) 96 MPI processes<br>
> type: gamg<br>
> MG: type is MULTIPLICATIVE, levels=4 cycles=v<br>
> Cycles per PCApply=1<br>
> Using Galerkin computed coarse grid matrices<br>
> Coarse grid solver -- level -------------------------------<br>
> KSP Object: (pres_redistribute_mg_coarse_) 96 MPI processes<br>
> type: preonly<br>
> maximum iterations=1, initial guess is zero<br>
> tolerances: relative=1e-05, absolute=1e-50, divergence=10000<br>
> left preconditioning<br>
> using NONE norm type for convergence test<br>
> PC Object: (pres_redistribute_mg_coarse_) 96 MPI processes<br>
> type: sor<br>
> SOR: type = local_symmetric, iterations = 4, local iterations = 1, omega = 1<br>
> linear system matrix = precond matrix:<br>
> Mat Object: 96 MPI processes<br>
> type: mpiaij<br>
> rows=465, cols=465<br>
> total: nonzeros=84523, allocated nonzeros=84523<br>
> total number of mallocs used during MatSetValues calls =0<br>
> not using I-node (on process 0) routines<br>
> Down solver (pre-smoother) on level 1 -------------------------------<br>
> KSP Object: (pres_redistribute_mg_levels_1_) 96 MPI processes<br>
> type: richardson<br>
> Richardson: damping factor=1<br>
> maximum iterations=2<br>
> tolerances: relative=1e-05, absolute=1e-50, divergence=10000<br>
> left preconditioning<br>
> using nonzero initial guess<br>
> using NONE norm type for convergence test<br>
> PC Object: (pres_redistribute_mg_levels_1_) 96 MPI processes<br>
> type: sor<br>
> SOR: type = local_symmetric, iterations = 1, local iterations = 1, omega = 1<br>
> linear system matrix = precond matrix:<br>
> Mat Object: 96 MPI processes<br>
> type: mpiaij<br>
> rows=13199, cols=13199<br>
> total: nonzeros=2.09436e+06, allocated nonzeros=2.09436e+06<br>
> total number of mallocs used during MatSetValues calls =0<br>
> not using I-node (on process 0) routines<br>
> Up solver (post-smoother) same as down solver (pre-smoother)<br>
> Down solver (pre-smoother) on level 2 -------------------------------<br>
> KSP Object: (pres_redistribute_mg_levels_2_) 96 MPI processes<br>
> type: richardson<br>
> Richardson: damping factor=1<br>
> maximum iterations=2<br>
> tolerances: relative=1e-05, absolute=1e-50, divergence=10000<br>
> left preconditioning<br>
> using nonzero initial guess<br>
> using NONE norm type for convergence test<br>
> PC Object: (pres_redistribute_mg_levels_2_) 96 MPI processes<br>
> type: sor<br>
> SOR: type = local_symmetric, iterations = 1, local iterations = 1, omega = 1<br>
> linear system matrix = precond matrix:<br>
> Mat Object: 96 MPI processes<br>
> type: mpiaij<br>
> rows=568202, cols=568202<br>
> total: nonzeros=2.33509e+07, allocated nonzeros=2.33509e+07<br>
> total number of mallocs used during MatSetValues calls =0<br>
> not using I-node (on process 0) routines<br>
> Up solver (post-smoother) same as down solver (pre-smoother)<br>
> Down solver (pre-smoother) on level 3 -------------------------------<br>
> KSP Object: (pres_redistribute_mg_levels_3_) 96 MPI processes<br>
> type: richardson<br>
> Richardson: damping factor=1<br>
> maximum iterations=2<br>
> tolerances: relative=1e-05, absolute=1e-50, divergence=10000<br>
> left preconditioning<br>
> using nonzero initial guess<br>
> using NONE norm type for convergence test<br>
> PC Object: (pres_redistribute_mg_levels_3_) 96 MPI processes<br>
> type: sor<br>
> SOR: type = local_symmetric, iterations = 1, local iterations = 1, omega = 1<br>
> linear system matrix = precond matrix:<br>
> Mat Object: 96 MPI processes<br>
> type: mpiaij<br>
> rows=9017583, cols=9017583<br>
> total: nonzeros=1.01192e+08, allocated nonzeros=1.01192e+08<br>
> total number of mallocs used during MatSetValues calls =0<br>
> not using I-node (on process 0) routines<br>
> Up solver (post-smoother) same as down solver (pre-smoother)<br>
> linear system matrix = precond matrix:<br>
> Mat Object: 96 MPI processes<br>
> type: mpiaij<br>
> rows=9017583, cols=9017583<br>
> total: nonzeros=1.01192e+08, allocated nonzeros=1.01192e+08<br>
> total number of mallocs used during MatSetValues calls =0<br>
> not using I-node (on process 0) routines<br>
> linear system matrix = precond matrix:<br>
> Mat Object: proj_A 96 MPI processes<br>
> type: mpiaij<br>
> rows=16133102, cols=16133102<br>
> total: nonzeros=1.09807e+08, allocated nonzeros=1.57582e+08<br>
> total number of mallocs used during MatSetValues calls =0<br>
> not using I-node (on process 0) routines<br>
> Residual norms for vel_ solve.<br>
><br>
<br>
</div></div></blockquote></div><br></div>