the default LU solver in sequential is the PETSc one which does not support pivoting or singular problems. In parallel, it is either MUMPS or SUPERLU_DIST, depending on your configurations. MUMPS for example can handle singular problem, not sure about superlu_dist. You can run the parallel version with -ksp_view and see what is the solver package used. Supposing it is mumps, you can run the sequential code with -pc_factor_mat_solver_type mumps
Il giorno gio 7 nov 2024 alle ore 13:20 Klaij, Christiaan via petsc-users < petsc-users@mcs.anl.gov> ha scritto: > I'm trying to solve a system with a single, non-constant, null space > vector, confirmed by passing the MatNullSpaceTest. Solving the system works > fine with -pc_type ilu on one or multiple procs. It also works fine with > -pc_type lu on multiple procs but fails on a single proc. Any idea what > could be wrong? > > Chris > > [0]PETSC ERROR: *** unknown floating point error occurred *** > [0]PETSC ERROR: The specific exception can be determined by running in a > debugger. When the > [0]PETSC ERROR: debugger traps the signal, the exception can be found with > fetestexcept(0x3f) > [0]PETSC ERROR: where the result is a bitwise OR of the following flags: > [0]PETSC ERROR: FE_INVALID=0x1 FE_DIVBYZERO=0x4 FE_OVERFLOW=0x8 > FE_UNDERFLOW=0x10 FE_INEXACT=0x20 > [0]PETSC ERROR: Try option -start_in_debugger > [0]PETSC ERROR: likely location of problem given in stack below > [0]PETSC ERROR: --------------------- Stack Frames > ------------------------------------ > [0]PETSC ERROR: The line numbers in the error traceback are not always > exact. > [0]PETSC ERROR: #1 PetscDefaultFPTrap() at > /cm/shared/apps/petsc/oneapi/build/src/src/sys/error/fp.c:487 > [0]PETSC ERROR: #2 VecMDot_Seq() at > /cm/shared/apps/petsc/oneapi/build/src/src/vec/vec/impls/seq/dvec2.c:189 > [0]PETSC ERROR: #3 VecMXDot_MPI_Default() at > /cm/shared/apps/petsc/oneapi/build/src/include/../src/vec/vec/impls/mpi/pvecimpl.h:96 > [0]PETSC ERROR: #4 VecMDot_MPI() at > /cm/shared/apps/petsc/oneapi/build/src/src/vec/vec/impls/mpi/pvec2.c:25 > [0]PETSC ERROR: #5 VecMXDot_Private() at > /cm/shared/apps/petsc/oneapi/build/src/src/vec/vec/interface/rvector.c:1112 > [0]PETSC ERROR: #6 VecMDot() at > /cm/shared/apps/petsc/oneapi/build/src/src/vec/vec/interface/rvector.c:1184 > [0]PETSC ERROR: #7 MatNullSpaceRemove() at > /cm/shared/apps/petsc/oneapi/build/src/src/mat/interface/matnull.c:359 > [0]PETSC ERROR: #8 KSP_RemoveNullSpace() at > /cm/shared/apps/petsc/oneapi/build/src/include/petsc/private/kspimpl.h:322 > [0]PETSC ERROR: #9 KSP_PCApply() at > /cm/shared/apps/petsc/oneapi/build/src/include/petsc/private/kspimpl.h:382 > [0]PETSC ERROR: #10 KSPInitialResidual() at > /cm/shared/apps/petsc/oneapi/build/src/src/ksp/ksp/interface/itres.c:64 > [0]PETSC ERROR: #11 KSPSolve_GMRES() at > /cm/shared/apps/petsc/oneapi/build/src/src/ksp/ksp/impls/gmres/gmres.c:226 > [0]PETSC ERROR: #12 KSPSolve_Private() at > /cm/shared/apps/petsc/oneapi/build/src/src/ksp/ksp/interface/itfunc.c:898 > [0]PETSC ERROR: #13 KSPSolve() at > /cm/shared/apps/petsc/oneapi/build/src/src/ksp/ksp/interface/itfunc.c:1070 > [0]PETSC ERROR: --------------------- Error Message > -------------------------------------------------------------- > [0]PETSC ERROR: Floating point exception > [0]PETSC ERROR: trapped floating point error > [0]PETSC ERROR: See > https://urldefense.us/v3/__https://petsc.org/release/faq/__;!!G_uCfscf7eWS!YEL_7P5zQIFYD7bhZCjy9YmnEJKPrk8uuZ-HgzitChAgA3TpOY2MKoRQcBcC6LuKxc3x8WMoVQ62WS53A7XCLS4niHz5JWI$ > > <https://urldefense.us/v3/__https://petsc.org/release/faq/__;!!G_uCfscf7eWS!dXxAqHgHbtticGbE-cswI2ylVIt4A7Fn68LPFMyFtpJByLQtJocy5JF-Vf5Vzr_FbcWB1l7ve_2l9CdBfaa2Fyw$> > for trouble shooting. > [0]PETSC ERROR: Petsc Release Version 3.19.4, Jul 31, 2023 > [0]PETSC ERROR: ./refresco on a named marclus3login2 by cklaij Thu Nov 7 > 11:03:22 2024 > [0]PETSC ERROR: Configure options > --prefix=/cm/shared/apps/petsc/oneapi/3.19.4-dbg > --with-mpi-dir=/cm/shared/apps/intel/oneapi/mpi/2021.4.0 --with-x=0 > --with-mpe=0 --with-debugging=1 > --download-superlu_dist=../superlu_dist-8.1.2.tar.gz > --with-blaslapack-dir=/cm/shared/apps/intel/oneapi/mkl/2021.4.0 > --download-parmetis=../parmetis-4.0.3-p9.tar.gz > --download-metis=../metis-5.1.0-p11.tar.gz > --with-packages-build-dir=/cm/shared/apps/petsc/oneapi/build --with-ssl=0 > --with-shared-libraries=1 CFLAGS="-std=gnu11 -Wall -funroll-all-loops -O3 > -DNDEBUG" CXXFLAGS="-std=gnu++14 -Wall -funroll-all-loops -O3 -DNDEBUG" > COPTFLAGS="-std=gnu11 -Wall -funroll-all-loops -O3 -DNDEBUG" > CXXOPTFLAGS="-std=gnu++14 -Wall -funroll-all-loops -O3 -DNDEBUG" > FCFLAGS="-funroll-all-loops -O3 -DNDEBUG" F90FLAGS="-funroll-all-loops -O3 > -DNDEBUG" FOPTFLAGS="-funroll-all-loops -O3 -DNDEBUG" > Abort(72) on node 0 (rank 0 in comm 0): application called > MPI_Abort(MPI_COMM_WORLD, 72) - process 0 > dr. ir. Christiaan Klaij > | Senior Researcher | Research & Development > T +31 317 49 33 44 <+31%20317%2049%2033%2044> | c.kl...@marin.nl | > https://urldefense.us/v3/__http://www.marin.nl__;!!G_uCfscf7eWS!YEL_7P5zQIFYD7bhZCjy9YmnEJKPrk8uuZ-HgzitChAgA3TpOY2MKoRQcBcC6LuKxc3x8WMoVQ62WS53A7XCLS4nR49qdbI$ > > <https://urldefense.us/v3/__https://www.marin.nl/__;!!G_uCfscf7eWS!dXxAqHgHbtticGbE-cswI2ylVIt4A7Fn68LPFMyFtpJByLQtJocy5JF-Vf5Vzr_FbcWB1l7ve_2l9CdBivdTTos$> > [image: Facebook] > <https://urldefense.us/v3/__https://www.facebook.com/marin.wageningen__;!!G_uCfscf7eWS!dXxAqHgHbtticGbE-cswI2ylVIt4A7Fn68LPFMyFtpJByLQtJocy5JF-Vf5Vzr_FbcWB1l7ve_2l9CdBNyhbEjY$> > [image: LinkedIn] > <https://urldefense.us/v3/__https://www.linkedin.com/company/marin__;!!G_uCfscf7eWS!dXxAqHgHbtticGbE-cswI2ylVIt4A7Fn68LPFMyFtpJByLQtJocy5JF-Vf5Vzr_FbcWB1l7ve_2l9CdBs7HDGBM$> > [image: YouTube] > <https://urldefense.us/v3/__https://www.youtube.com/marinmultimedia__;!!G_uCfscf7eWS!dXxAqHgHbtticGbE-cswI2ylVIt4A7Fn68LPFMyFtpJByLQtJocy5JF-Vf5Vzr_FbcWB1l7ve_2l9CdBTcqrSW8$> > -- Stefano
