[petsc-dev] GAMG key not found in table

[Smith, Barry F.]

> On Jun 24, 2018, at 11:15 AM, Mark Adams <mfadams at lbl.gov> wrote:
> 
> First, -pc_gamg_threshold 0.8  is crazy. 0.08 is very high. probably best to start with 0.
> 
> This threshold will delete all of your edges in the coarsening graph, probably, and GAMG will switch to a one level solve (silently although -info will tell you).
> 
> And yes, this looks like a 64 bit indices problem, we have:
> 
> #define GAMG_HASH(key) ((((PetscInt)7)*key)%a_tab->size)
> 
> We should probably cast everything to (long long) or (unsigned PetscInt) I guess ... I'm not sure how this should be done exactly.  Any ideas from the peanut gallery?

Mark,

     It should only be changed if we know the exact mechanism that causes the failure. It is not obvious to me that just changing ((((PetscInt)7)*key)%a_tab->size) to ((((PetscInt64)7)*key)%a_tab->size) should matter.

   Barry

> 
> 
> 
> On Sun, Jun 24, 2018 at 2:34 AM Pierre Jolivet <pierre.jolivet at enseeiht.fr> wrote:
> Hello,
> Any ideas on how to debug this?
> [406]PETSC ERROR: key 328214936 not found in table
> [406]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html for trouble shooting.
> [406]PETSC ERROR: Petsc Development GIT revision: v3.9.2-603-gceafe64  GIT Date: 2018-06-10 12:46:16 -0500
> [406]PETSC ERROR: /ccc/work/cont003/rndm/rndm/FreeFem-sources/src/mpi/FreeFem++-mpi on a arch-linux2-c-debug-bullxmpi named curie2698 by jolivetp Sun Jun 24 07:06:07 2018
> [406]PETSC ERROR: Configure options --with-scalar-type=real --with-hypre-dir=arch-linux2-c-opt-bullxmpi --with-metis-dir=arch-linux2-c-opt-bullxmpi --with-mumps-dir=arch-linux2-c-opt-bullxmpi --with-mkl_cpardiso=1 --with-mkl_pardiso=1 --with-parmetis-dir=arch-linux2-c-opt-bullxmpi --with-ptscotch-dir=arch-linux2-c-opt-bullxmpi --with-sowing-dir=arch-linux2-c-opt-bullxmpi --with-blacs-include=/ccc/products/mkl-18.0.1.163/default/18.0.1.163/mkl/include --with-blacs-lib=/ccc/products/mkl-18.0.1.163/default/18.0.1.163/mkl/lib/intel64/libmkl_blacs_openmpi_lp64.so --with-blaslapack-dir=/ccc/products/mkl-18.0.1.163/default/18.0.1.163/mkl/lib/intel64 --with-x=0 --with-debugging=1 --with-errorchecking=1 --with-mkl_pardiso-dir=/ccc/products/mkl-18.0.1.163/default/18.0.1.163/mkl --with-mkl_cpardiso-dir=/ccc/products/mkl-18.0.1.163/default/18.0.1.163/mkl --with-scalapack-include=/ccc/products/mkl-18.0.1.163/default/18.0.1.163/mkl/include --with-scalapack-lib="[/ccc/products/mkl-18.0.1.163/default/18.0.1.163/mkl/lib/intel64/libmkl_scalapack_lp64.so,/ccc/products/mkl-18.0.1.163/default/18.0.1.163/mkl/lib/intel64/libmkl_blacs_openmpi_lp64.so]" --with-fortran-bindings=0 PETSC_ARCH=arch-linux2-c-debug-bullxmpi
> [406]PETSC ERROR: #1 PCGAMGHashTableFind() line 106 in /ccc/work/cont003/rndm/rndm/petsc/include/petsc/private/pcgamgimpl.h
> [406]PETSC ERROR: #2 smoothAggs() line 526 in /ccc/work/cont003/rndm/rndm/petsc/src/ksp/pc/impls/gamg/agg.c
> [406]PETSC ERROR: #3 PCGAMGCoarsen_AGG() line 970 in /ccc/work/cont003/rndm/rndm/petsc/src/ksp/pc/impls/gamg/agg.c
> [406]PETSC ERROR: #4 PCSetUp_GAMG() line 518 in /ccc/work/cont003/rndm/rndm/petsc/src/ksp/pc/impls/gamg/gamg.c
> [406]PETSC ERROR: #5 PCSetUp() line 932 in /ccc/work/cont003/rndm/rndm/petsc/src/ksp/pc/interface/precon.c
> [406]PETSC ERROR: #6 KSPSetUp() line 381 in /ccc/work/cont003/rndm/rndm/petsc/src/ksp/ksp/interface/itfunc.c
> 
> For smaller problems, this works fine. Should I compile using 64 bit indices?
> I’m using -pc_type gamg -pc_gamg_threshold 0.8 -pc_gamg_agg_nsmooths 1 -pc_gamg_sym_graph true -pc_gamg_square_graph 10
> 
> Thanks,
> Pierre