[petsc-dev] [petsc-maint #154101] clarification of FP error thrown in VECNORM in 3.3 PETSc

[Barry Smith]

  Steve,

    Thanks for your report and sorry about the difficulties. We made the change thinking the sooner we report a FP error the better for the user. But you are right that sometimes it makes sense for the application to handle it directly.

    We will figure out a way to manage this. I am thinking a global flag you can set indicating you don't want these checks performed; then you will get back the previous behavior.

   Barry

On Feb 22, 2013, at 5:07 PM, "Cea, Stephen M" <stephen.m.cea at intel.com> wrote:

> Hi,
> 
>               We are upgrading from 3.0 to 3.3 version of PETSc.  It is looking good because it is considerably faster.   We have one issue that the vecnorm has been changed and it sets an error if finds a nan / inf in the vector.  See message at the end.    We have always exited the program when we get a PETSc error but for this case it is not a good idea since  we used to find this ourselves and then cut the timestep and resolve.    We might be able to just treat the error from KSPSolve    ( iError = KSPSolve(slp.sles, b, x); ) as non convergence and cut the time step and resolve.   But I am wondering if we can tell from the return which error it is.   I tried looking in the manual but couldn't find a list of error codes etc.
> 
> Thanks,
> steve
> 
> 
> 
> 
> 
> [0]PETSC ERROR: --------------------- Error Message ------------------------------------
> [0]PETSC ERROR: Floating point exception!
> [0]PETSC ERROR: Infinite or not-a-number generated in norm!
> [0]PETSC ERROR: ------------------------------------------------------------------------
> [0]PETSC ERROR: Petsc Release Version 3.3.0, Patch 3, Wed Aug 29 11:26:24 CDT 2012
> [0]PETSC ERROR: See docs/changes/index.html for recent updates.
> [0]PETSC ERROR: See docs/faq.html for hints about trouble shooting.
> [0]PETSC ERROR: See docs/index.html for manual pages.
> [0]PETSC ERROR: ------------------------------------------------------------------------
> [0]PETSC ERROR: /nfs/pdx/disks/tcad_ptm_pdmg_work_03/usr/adlilak/FLPSCHECKINS/FLPS_NZ_PETSC/floops/src/floops.linux64 on a with-CPP- named dlxc0894.jf.intel.com by adlilak Thu Feb 21 23:43:15 2013
> [0]PETSC ERROR: Libraries linked from /p/dt/sdework9/mrduda/INN/Build2/petsc-3.3-p3/with-CPP-nomumps-icc13/lib
> [0]PETSC ERROR: Configure run at Fri Oct 19 09:42:58 2012
> [0]PETSC ERROR: Configure options --with-debugging=0 --with-mpi-compilers=0 --with-mpi-shared=0 --with-mpi=1 --with-mpi-include=/p/dt/sde/tools/em64t_SLES10/MPI/4.0.3.004/include64 --with-mpi-lib="[/p/dt/sde/tools/em64t_SLES10/MPI/4.0.3.004/lib64/libmpi.a,/p/dt/sde/tools/em64t_SLES10/MPI/4.0.3.004/lib64/libmpiif.a]" --with-clanguage=C++ --with-vendor-compilers=intel --with-cc=icc --COPTFLAGS="-O2 -g -sox" --with-cxx=icpc --CXXOPTFLAGS="-O2 -g -sox" --with-fc=ifort --FOPTFLAGS="-O2 -g -sox" --LDFLAGS=-Wl,-rpath,$GCCDIR/lib64 --with-blas-lapack-lib="[/p/dt/sdework12/mrduda/KNC/c_compiler/install/mkl/lib/intel64/libmkl_rt.so]" --with-scalapack=1 --with-scalapack-include=/p/dt/sdework12/mrduda/KNC/c_compiler/install/mkl/include --with-scalapack-lib=/p/dt/sdework12/mrduda/KNC/c_compiler/install/mkl/lib/intel64/libmkl_scalapack_lp64.a --with-blacs=1 --with-blacs-include=/p/dt/sdework12/mrduda/KNC/c_compiler/install/mkl/include --with-blacs-lib=/p/dt/sdework12/mrduda/KNC/c_compiler/
> install/mkl/lib/intel64/libmkl_blacs_intelmpi_lp64.a
> [0]PETSC ERROR: ------------------------------------------------------------------------
> [0]PETSC ERROR: VecNorm() line 169 in /p/dt/sdework9/mrduda/INN/Build2/petsc-3.3-p3/src/vec/vec/interface/rvector.c
> [0]PETSC ERROR: KSPSolve_BCGS() line 78 in /p/dt/sdework9/mrduda/INN/Build2/petsc-3.3-p3/src/ksp/ksp/impls/bcgs/bcgs.c
> [0]PETSC ERROR: KSPSolve() line 446 in /p/dt/sdework9/mrduda/INN/Build2/petsc-3.3-p3/src/ksp/ksp/interface/itfunc.c
> 
>