[petsc-users] Infinite or not-a-number generated in norm!

[Dominik Szczerba]

> Is your system singular? Or perhaps the BoomerAMG smoother is not stable for
> your problem. You didn't show the full stack.

Below a full stack.

Yes, I am a bit malicious, solving for steady state where such is
known not to exists (Karman vortex street past a cylinder). The very
same problem (mesh, constraints, etc.) does not crash when solving
with time stepping. However, I am not completely sure if this is the
reason of the crash, because I am expecting to never be able to
converge, but not to crash.

Thanks
Dominik

Program received signal SIGFPE, Arithmetic exception.
0x00000000010fad4e in hypre_BoomerAMGRelax (A=0x1a1109a0, f=0x180ea7b0,
    cf_marker=0x54cd900, relax_type=6, relax_points=1, relax_weight=1,
    omega=1, l1_norms=0x0, u=0x9c9aaa0, Vtemp=0x17b73900, Ztemp=0x0)
    at par_relax.c:1925
1925                      u_data[i] = res / A_diag_data[A_diag_i[i]];
(gdb) bt
#0  0x00000000010fad4e in hypre_BoomerAMGRelax (A=0x1a1109a0, f=0x180ea7b0,
    cf_marker=0x54cd900, relax_type=6, relax_points=1, relax_weight=1,
    omega=1, l1_norms=0x0, u=0x9c9aaa0, Vtemp=0x17b73900, Ztemp=0x0)
    at par_relax.c:1925
#1  0x00000000010fff7a in hypre_BoomerAMGRelaxIF (A=0x1a1109a0, f=0x180ea7b0,
    cf_marker=0x54cd900, relax_type=6, relax_order=1, cycle_type=1,
    relax_weight=1, omega=1, l1_norms=0x0, u=0x9c9aaa0, Vtemp=0x17b73900,
    Ztemp=0x0) at par_relax_interface.c:59
#2  0x00000000010c0d38 in hypre_BoomerAMGCycle (amg_vdata=0x9930b60, F_array=
    0x9cd8880, U_array=0x10f01640) at par_cycle.c:486
#3  0x00000000010acc47 in hypre_BoomerAMGSolve (amg_vdata=0x9930b60, A=
    0x221dfa0, f=0x9d85be0, u=0x9a32710) at par_amg_solve.c:252
#4  0x000000000109ea0f in HYPRE_BoomerAMGSolve (solver=0x9930b60, A=0x221dfa0,
    b=0x9d85be0, x=0x9a32710) at HYPRE_parcsr_amg.c:76
#5  0x00000000007ef30b in PCApply_HYPRE (pc=0x10d8ff90, b=0x9cbed40,
    x=0x9cb5420)
    at /home/dsz/pack/petsc-3.2-p5/src/ksp/pc/impls/hypre/hypre.c:159
#6  0x000000000081628c in PCApply (pc=0x10d8ff90, x=0x9cbed40, y=0x9cb5420)
    at /home/dsz/pack/petsc-3.2-p5/src/ksp/pc/interface/precon.c:383
#7  0x0000000000953cdb in KSPSolve_PREONLY (ksp=0x9aa05d0)
    at /home/dsz/pack/petsc-3.2-p5/src/ksp/ksp/impls/preonly/preonly.c:26
#8  0x00000000008e25a6 in KSPSolve (ksp=0x9aa05d0, b=0x9cbed40, x=0x9cb5420)
    at /home/dsz/pack/petsc-3.2-p5/src/ksp/ksp/interface/itfunc.c:423
---Type <return> to continue, or q <return> to quit---
#9  0x0000000000504dfb in FluidSolver::ApplyPreconditioner (prec=0x10f013f0,
    x=0x10f12260, y=0x10f1bb40)
    at /home/dsz/src/framework/sandbox/dsz/cscs/solve/FluidSolver.cxx:3712
#10 0x000000000087c121 in PCApply_Shell (pc=0x10f013f0, x=0x10f12260,
    y=0x10f1bb40)
    at /home/dsz/pack/petsc-3.2-p5/src/ksp/pc/impls/shell/shellpc.c:121
#11 0x000000000081628c in PCApply (pc=0x10f013f0, x=0x10f12260, y=0x10f1bb40)
    at /home/dsz/pack/petsc-3.2-p5/src/ksp/pc/interface/precon.c:383
#12 0x00000000009604d7 in FGMREScycle (itcount=0x7fff03d02cd4, ksp=0x10eff220)
    at /home/dsz/pack/petsc-3.2-p5/src/ksp/ksp/impls/gmres/fgmres/fgmres.c:174
#13 0x00000000009611c0 in KSPSolve_FGMRES (ksp=0x10eff220)
    at /home/dsz/pack/petsc-3.2-p5/src/ksp/ksp/impls/gmres/fgmres/fgmres.c:299
#14 0x00000000008e25a6 in KSPSolve (ksp=0x10eff220, b=0x9c9a750, x=0x17a31310)
    at /home/dsz/pack/petsc-3.2-p5/src/ksp/ksp/interface/itfunc.c:423
#15 0x00000000004ef53f in FluidSolver::Solve (this=0x1da0000)
    at /home/dsz/src/framework/sandbox/dsz/cscs/solve/FluidSolver.cxx:1764
#16 0x000000000053dc2b in main (argc=4, argv=0x7fff03d05888)
    at /home/dsz/src/framework/sandbox/dsz/cscs/solve/FluidSolverMain.cxx:316