c 4 1.0976214263087059E-067 I don't think this number can be stored in a real*4.
Satish On Fri, 24 Apr 2015, Danyang Su wrote: > > > On 15-04-24 11:12 AM, Barry Smith wrote: > > > On Apr 24, 2015, at 1:05 PM, Danyang Su <[email protected]> wrote: > > > > > > Hi All, > > > > > > One of my case crashes because of floating point exception when using 4 > > > processors, as shown below. But if I run this case with 1 processor, it > > > works fine. I have tested the codes with around 100 cases up to 768 > > > processors, all other cases work fine. I just wonder if this kind of error > > > is caused because of NaN in jacobi matrix, RHS or preconditioner? > > Yes, almost for sure it is one of these places. > > > > First run the bad case with -fp_trap if all goes well you'll see the > > function where the FPE is generated. Then run also with -start_in_debugger > > and > > type cont in all four debugger windows. When the FPE happens the debugger > > should stop showing exactly where the FPE happens. > > > > Barry > Hi Barry, > > If run with -fp_trap -start_in_debugger, I got the following error > > [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(0x3d) > [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: Note: The EXACT line numbers in the stack are not available, > [0]PETSC ERROR: INSTEAD the line number of the start of the function > [0]PETSC ERROR: is given. > [0]PETSC ERROR: [0] PetscDefaultFPTrap line 379 > /home/dsu/Soft/PETSc/petsc-3.5.2/src/sys/error/fp.c > [0]PETSC ERROR: User provided function() line 0 in Unknown file trapped > floating point error > > Program received signal SIGABRT: Process abort signal. > > Backtrace for this error: > #0 0x7F4FEAB1C7D7 > #1 0x7F4FEAB1CDDE > #2 0x7F4FE9E1AD3F > #3 0x7F4FE9E1ACC9 > #4 0x7F4FE9E1E0D7 > #5 0x7F4FEB0B6DCB > #6 0x7F4FEB0B1825 > #7 0x7F4FEB0B817F > #8 0x7F4FE9E1AD3F > #9 0x6972C8 in tprfrtlc_ at tprfrtlc.F90:2393 (discriminator 3) > #10 0x4C6C87 in gcreact_ at gcreact.F90:678 > #11 0x707E19 in initicrt_ at initicrt.F90:589 > #12 0x4F42D0 in initprob_ at initprob.F90:430 > #13 0x5AAF72 in driver_pc at driver_pc.F90:438 > > I checked the code at tprfrtlc.F90:2393, > > realbuffer_gb(1:nvars) = (/time,(c(ic),ic=1,nc-1), & > (cx(ix),ix=1,nxout)/) > > All the values (time, c, cx) are reasonable, as shown below. The only > possibility is that realbuffer_gb is in declared as real*4 if using sing > precision output while time, c, cx are declared in real*8. I have a lot of > similar data conversion from real*8 to real*4 output, other code does not > return error. > > time 0.0000000000000000 > c 1 9.9999999999999995E-008 > c 2 3.1555251077549618E-003 > c 3 7.1657814842179362E-008 > c 4 1.0976214263087059E-067 > c 5 5.2879822292305797E-004 > c 6 9.9999999999999964E-005 > c 7 6.4055731968811337E-005 > c 8 3.4607572892578404E-020 > cx 1 3.4376650636008101E-005 > cx 2 7.3989678854017763E-012 > cx 3 9.5317170613607207E-012 > cx 4 2.2344525794718353E-015 > cx 5 3.0624685689695889E-008 > cx 6 1.0046157902783967E-007 > cx 7 1.5320169154914984E-004 > cx 8 8.6930292776346176E-014 > cx 9 3.5944267559348721E-005 > cx 10 3.0072645866951157E-018 > cx 11 2.3592486321095017E-013 > > Thanks, > > Danyang > > > > > > I can check all the entries of jacobi matrix to see if the value is valid, > > > but this seems not a good idea as it takes a long time to reach this > > > point. If I restart the simulation from a specified time (e.g., 7.685 in > > > this case), then the error does not occur. > > > > > > Would you please give me any suggestion on debugging this case? > > > > > > Thanks and Regards, > > > > > > Danyang > > > > > > > > > timestep: 2730 time: 7.665E+00 years delt: 1.000E-02 years iter: 1 > > > timestep: max.sia: 0.000E+00 tol.sia: 0.000E+00 > > > timestep: 2731 time: 7.675E+00 years delt: 1.000E-02 years iter: 1 > > > timestep: max.sia: 0.000E+00 tol.sia: 0.000E+00 > > > timestep: 2732 time: 7.685E+00 years delt: 1.000E-02 years iter: 1 > > > timestep: max.sia: 0.000E+00 tol.sia: 0.000E+00 > > > timestep: 2733 time: 7.695E+00 years delt: 1.000E-02 years iter: 1 > > > timestep: max.sia: 0.000E+00 tol.sia: 0.000E+00 > > > timestep: 2734 time: 7.705E+00 years delt: 1.000E-02 years iter: 1 > > > timestep: max.sia: 0.000E+00 tol.sia: 0.000E+00 > > > Reduce time step for reactive transport > > > timestep: 2734 time: 7.700E+00 years delt: 5.000E-03 years iter: 1 > > > timestep: max.sia: 0.000E+00 tol.sia: 0.000E+00 > > > Reduce time step for reactive transport > > > timestep: 2734 time: 7.697E+00 years delt: 2.500E-03 years iter: 1 > > > timestep: max.sia: 0.000E+00 tol.sia: 0.000E+00 > > > [1]PETSC ERROR: --------------------- Error Message > > > -------------------------------------------------------------- > > > [1]PETSC ERROR: Floating point exception > > > [2]PETSC ERROR: --------------------- Error Message > > > -------------------------------------------------------------- > > > [2]PETSC ERROR: Floating point exception > > > [2]PETSC ERROR: Vec entry at local location 0 is not-a-number or infinite > > > at end of function: Parameter number 3 > > > [2]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html > > > for trouble shooting. > > > [2]PETSC ERROR: Petsc Release Version 3.5.2, Sep, 08, 2014 > > > [2]PETSC ERROR: [1]PETSC ERROR: Vec entry at local location 0 is > > > not-a-number or infinite at end of function: Parameter number 3 > > > [1]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html > > > for trouble shooting. > > > [1]PETSC ERROR: Petsc Release Version 3.5.2, Sep, 08, 2014 > > > [1]PETSC ERROR: ../min3p_thcm_petsc_dbg on a linux-gnu-dbg named nwmop by > > > dsu Thu Apr 23 15:38:52 2015 > > > [1]PETSC ERROR: Configure options PETSC_ARCH=linux-gnu-dbg --with-cc=gcc > > > --with-cxx=g++ --with-fc=gfortran --download-fblaslapack --download-mpich > > > --download-mumps --download-hypre --download-superlu_dist --download-metis > > > --download-parmetis --download-scalapack > > > [1]PETSC ERROR: #1 VecValidValues() line 34 in > > > /home/dsu/Soft/PETSc/petsc-3.5.2/src/vec/vec/interface/rvector.c > > > ../min3p_thcm_petsc_dbg on a linux-gnu-dbg named nwmop by dsu Thu Apr 23 > > > 15:38:52 2015 > > > [2]PETSC ERROR: Configure options PETSC_ARCH=linux-gnu-dbg --with-cc=gcc > > > --with-cxx=g++ --with-fc=gfortran --download-fblaslapack --download-mpich > > > --download-mumps --download-hypre --download-superlu_dist --download-metis > > > --download-parmetis --download-scalapack > > > [2]PETSC ERROR: #1 VecValidValues() line 34 in > > > /home/dsu/Soft/PETSc/petsc-3.5.2/src/vec/vec/interface/rvector.c > > > [2]PETSC ERROR: [1]PETSC ERROR: #2 PCApply() line 442 in > > > /home/dsu/Soft/PETSc/petsc-3.5.2/src/ksp/pc/interface/precon.c > > > [1]PETSC ERROR: #2 PCApply() line 442 in > > > /home/dsu/Soft/PETSc/petsc-3.5.2/src/ksp/pc/interface/precon.c > > > [2]PETSC ERROR: #3 KSP_PCApply() line 230 in > > > /home/dsu/Soft/PETSc/petsc-3.5.2/include/petsc-private/kspimpl.h > > > #3 KSP_PCApply() line 230 in > > > /home/dsu/Soft/PETSc/petsc-3.5.2/include/petsc-private/kspimpl.h > > > [1]PETSC ERROR: #4 KSPInitialResidual() line 63 in > > > /home/dsu/Soft/PETSc/petsc-3.5.2/src/ksp/ksp/interface/itres.c > > > [2]PETSC ERROR: #4 KSPInitialResidual() line 63 in > > > /home/dsu/Soft/PETSc/petsc-3.5.2/src/ksp/ksp/interface/itres.c > > > [1]PETSC ERROR: #5 KSPSolve_GMRES() line 234 in > > > /home/dsu/Soft/PETSc/petsc-3.5.2/src/ksp/ksp/impls/gmres/gmres.c > > > [2]PETSC ERROR: #5 KSPSolve_GMRES() line 234 in > > > /home/dsu/Soft/PETSc/petsc-3.5.2/src/ksp/ksp/impls/gmres/gmres.c > > > [2]PETSC ERROR: #6 KSPSolve() line 459 in > > > /home/dsu/Soft/PETSc/petsc-3.5.2/src/ksp/ksp/interface/itfunc.c > > > [1]PETSC ERROR: #6 KSPSolve() line 459 in > > > /home/dsu/Soft/PETSc/petsc-3.5.2/src/ksp/ksp/interface/itfunc.c > > > ^C[mpiexec@nwmop] Sending Ctrl-C to processes as requested > > > [mpiexec@nwmop] Press Ctrl-C again to force abort > > >
