[petsc-users] Debugging suggestions: GAMG

Sanjay Govindjee s_g at berkeley.edu
Sat Jun 13 01:30:57 CDT 2020


I have a FEA problem that I am trying to solve with GAMG.  The problem 
solves
just fine with direct solvers (mumps, superlu) and iterative solvers 
(gmres, ml, hypre-boomer) etc.

However with GAMG I am getting a divide by zero that I am having trouble 
tracking down.  Below
is the gdb stack trace and the source lines going up the stack.

When I run in valgrind the problem runs fine (and gets the correct answer).
Valgrind reports nothing of note (just lots of indirectly lost blocks  
related to PMP_INIT).

I'm only running on one processor.

Any suggestions on where to start to trace the problem?

-sanjay

    #0  0x00007fb262dc5be1 in ieeeck_ () from /lib64/liblapack.so.3
    #1  0x00007fb262dc5332 in ilaenv_ () from /lib64/liblapack.so.3
    #2  0x00007fb262dbbcef in dlasq2_ () from /lib64/liblapack.so.3
    #3  0x00007fb262dbb78c in dlasq1_ () from /lib64/liblapack.so.3
    #4  0x00007fb262da1e2e in dbdsqr_ () from /lib64/liblapack.so.3
    #5  0x00007fb262960110 in dgesvd_ () from /lib64/liblapack.so.3
    #6  0x00007fb264e74b66 in KSPComputeExtremeSingularValues_GMRES
    (ksp=0x1816560, emax=0x7ffc5010e7c8, emin=0x7ffc5010e7d0) at
    /home/sg/petsc-3.13.2/src/ksp/ksp/impls/gmres/gmreig.c:32
    #7  0x00007fb264dfe69a in KSPComputeExtremeSingularValues
    (ksp=0x1816560, emax=0x7ffc5010e7c8, emin=0x7ffc5010e7d0) at
    /home/sg/petsc-3.13.2/src/ksp/ksp/interface/itfunc.c:64
    #8  0x00007fb264b44a1f in PCGAMGOptProlongator_AGG (pc=0x12f3d30,
    Amat=0x11a2630, a_P=0x7ffc5010ebe0) at
    /home/sg/petsc-3.13.2/src/ksp/pc/impls/gamg/agg.c:1145
    #9  0x00007fb264b248a1 in PCSetUp_GAMG (pc=0x12f3d30) at
    /home/sg/petsc-3.13.2/src/ksp/pc/impls/gamg/gamg.c:557
    #10 0x00007fb264d8535b in PCSetUp (pc=0x12f3d30) at
    /home/sg/petsc-3.13.2/src/ksp/pc/interface/precon.c:898
    #11 0x00007fb264e01a93 in KSPSetUp (ksp=0x128dd80) at
    /home/sg/petsc-3.13.2/src/ksp/ksp/interface/itfunc.c:376
    #12 0x00007fb264e057af in KSPSolve_Private (ksp=0x128dd80,
    b=0x1259f30, x=0x125d910) at
    /home/sg/petsc-3.13.2/src/ksp/ksp/interface/itfunc.c:633
    #13 0x00007fb264e086b9 in KSPSolve (ksp=0x128dd80, b=0x1259f30,
    x=0x125d910) at /home/sg/petsc-3.13.2/src/ksp/ksp/interface/itfunc.c:853
    #14 0x00007fb264e46216 in kspsolve_ (ksp=0x832670
    <__pfeapc_MOD_kspsol>, b=0x832698 <__pfeapc_MOD_rhs>, x=0x8326a0
    <__pfeapc_MOD_sol>, __ierr=0x7ffc5010f358)
         at
    /home/sg/petsc-3.13.2/src/ksp/ksp/interface/ftn-auto/itfuncf.c:266
    #15 0x000000000043298d in usolve (flags=..., b=...) at usolve.F:313
    #16 0x000000000044afba in psolve (stype=-3, b=..., fp=...,
    factor=.TRUE., solve=.TRUE., cfr=.FALSE., prnt=.TRUE.) at psolve.f:212
    #17 0x00000000006b7393 in pmacr1 (lct=..., ct=..., j=3,
    _lct=_lct at entry=15) at pmacr1.f:578
    #18 0x00000000005c247b in pmacr (initf=.FALSE.) at pmacr.f:578
    #19 0x000000000044ff20 in pcontr () at pcontr.f:1307
    #20 0x0000000000404d9b in feap () at feap86.f:162
    #21 main (argc=<optimized out>, argv=<optimized out>) at feap86.f:168
    #22 0x00007fb261aaef43 in __libc_start_main () from /lib64/libc.so.6
    #23 0x0000000000404dde in _start ()

    (gdb) list
    1       <built-in>: No such file or directory.
    (gdb) up
    #1  0x00007fb262dc5332 in ilaenv_ () from /lib64/liblapack.so.3
    (gdb) up
    #2  0x00007fb262dbbcef in dlasq2_ () from /lib64/liblapack.so.3
    (gdb) up
    #3  0x00007fb262dbb78c in dlasq1_ () from /lib64/liblapack.so.3
    (gdb) up
    #4  0x00007fb262da1e2e in dbdsqr_ () from /lib64/liblapack.so.3
    (gdb) up
    #5  0x00007fb262960110 in dgesvd_ () from /lib64/liblapack.so.3
    (gdb) up
    #6  0x00007fb264e74b66 in KSPComputeExtremeSingularValues_GMRES
    (ksp=0x1816560, emax=0x7ffc5010e7c8, emin=0x7ffc5010e7d0) at
    /home/sg/petsc-3.13.2/src/ksp/ksp/impls/gmres/gmreig.c:32
    32
    PetscStackCallBLAS("LAPACKgesvd",LAPACKgesvd_("N","N",&bn,&bn,R,&bN,realpart,&sdummy,&idummy,&sdummy,&idummy,work,&lwork,&lierr));
    (gdb) up
    #7  0x00007fb264dfe69a in KSPComputeExtremeSingularValues
    (ksp=0x1816560, emax=0x7ffc5010e7c8, emin=0x7ffc5010e7d0) at
    /home/sg/petsc-3.13.2/src/ksp/ksp/interface/itfunc.c:64
    64          ierr =
    (*ksp->ops->computeextremesingularvalues)(ksp,emax,emin);CHKERRQ(ierr);
    (gdb) up
    #8  0x00007fb264b44a1f in PCGAMGOptProlongator_AGG (pc=0x12f3d30,
    Amat=0x11a2630, a_P=0x7ffc5010ebe0) at
    /home/sg/petsc-3.13.2/src/ksp/pc/impls/gamg/agg.c:1145
    1145          ierr = KSPComputeExtremeSingularValues(eksp, &emax,
    &emin);CHKERRQ(ierr);
    (gdb) up
    #9  0x00007fb264b248a1 in PCSetUp_GAMG (pc=0x12f3d30) at
    /home/sg/petsc-3.13.2/src/ksp/pc/impls/gamg/gamg.c:557
    557               ierr = pc_gamg->ops->optprolongator(pc,
    Aarr[level], &Prol11);CHKERRQ(ierr);
    (gdb) up
    #10 0x00007fb264d8535b in PCSetUp (pc=0x12f3d30) at
    /home/sg/petsc-3.13.2/src/ksp/pc/interface/precon.c:898
    898         ierr = (*pc->ops->setup)(pc);CHKERRQ(ierr);
    (gdb) up
    #11 0x00007fb264e01a93 in KSPSetUp (ksp=0x128dd80) at
    /home/sg/petsc-3.13.2/src/ksp/ksp/interface/itfunc.c:376
    376       ierr = PCSetUp(ksp->pc);CHKERRQ(ierr);
    (gdb) up
    #12 0x00007fb264e057af in KSPSolve_Private (ksp=0x128dd80,
    b=0x1259f30, x=0x125d910) at
    /home/sg/petsc-3.13.2/src/ksp/ksp/interface/itfunc.c:633
    633       ierr = KSPSetUp(ksp);CHKERRQ(ierr);
    (gdb) up
    #13 0x00007fb264e086b9 in KSPSolve (ksp=0x128dd80, b=0x1259f30,
    x=0x125d910) at /home/sg/petsc-3.13.2/src/ksp/ksp/interface/itfunc.c:853
    853       ierr = KSPSolve_Private(ksp,b,x);CHKERRQ(ierr);
    (gdb) up
    #14 0x00007fb264e46216 in kspsolve_ (ksp=0x832670
    <__pfeapc_MOD_kspsol>, b=0x832698 <__pfeapc_MOD_rhs>, x=0x8326a0
    <__pfeapc_MOD_sol>, __ierr=0x7ffc5010f358)
         at
    /home/sg/petsc-3.13.2/src/ksp/ksp/interface/ftn-auto/itfuncf.c:266
    266     *__ierr = KSPSolve(
    (gdb) up
    #15 0x000000000043298d in usolve (flags=..., b=...) at usolve.F:313
    313               call KSPSolve         (kspsol, rhs, sol, ierr)



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