On 15-04-29 11:30 AM, Barry Smith wrote:
On Apr 29, 2015, at 12:15 PM, Danyang Su <[email protected]> wrote:
On 15-04-28 06:50 PM, Barry Smith wrote:
We started enforcing more checks on writing to vectors that you should not
write to. Where are you calling DMLocalToGlobalBegin() ? It looks like you are
trying to copy values into a global array that you should not because it is a
read only input to a function, for example it is the right hand side of a
linear system or the input into a SNESFormFunction(). So check the output to
that call.
Barry
This is used when local RHS vec is calculated and copied to global RHS.
Huhh, why are you copying anything into the RHS? Is this before you call
the linear system solve? Send the code that calls the DMLocalToGlobalBegin()
Yes. This is called before the linear system solver. At present, we use
PETSc KSP solver.
The code is first developed in totally sequential version and then
ported to the parallel version. So the subdomain has its own space for
jacobi matrix and rhs. We do not use global RHS vector directly to set
the RHS at this moment. All the RHS values of subdomain are copied to
the global RHS.
!> This is the function where RHS values of subdomain are copied
to the global RHS values.
subroutine compute_function(rank,da,x_array_loc,x_vec_loc, &
x_vec_gbl,nngl,row_idx_l2pg,col_idx_l2pg, &
b_non_interlaced)
implicit none
#include <finclude/petscsys.h>
#include <finclude/petscis.h>
#include <finclude/petscvec.h>
#include <finclude/petscvec.h90>
#include <finclude/petscmat.h>
#include <finclude/petscpc.h>
#include <finclude/petscksp.h>
#include <finclude/petscdmda.h>
#include <finclude/petscdmda.h90>
PetscInt :: rank
DM :: da
PetscReal, allocatable :: x_array_loc(:)
Vec :: x_vec_loc
Vec :: x_vec_gbl
PetscInt :: nngl
PetscInt, allocatable :: row_idx_l2pg(:)
PetscInt, allocatable :: col_idx_l2pg(:)
PetscBool :: b_non_interlaced
PetscInt :: info_debug
PetscInt :: i, j
PetscErrorCode :: ierr
PetscScalar, pointer :: vecpointer(:)
!Zero entries
call VecZeroEntries(x_vec_loc, ierr)
!Get a pointer to vector data when you need access to the array
call VecGetArrayF90(x_vec_loc, vecpointer, ierr)
!Compute the function over the locally owned part of the grid
if(b_non_interlaced) then
j = nngl/2
do i = 1, j
vecpointer(2*i-1) = x_array_loc(i)
vecpointer(2*i) = x_array_loc(i+j)
end do
else
do i = 1, nngl
vecpointer(i) = x_array_loc(i)
end do
end if
!Restore the vector when you no longer need access to the array
call VecRestoreArrayF90(x_vec_loc,vecpointer,ierr)
!Insert values into global vector
call DMLocalToGlobalBegin(da,x_vec_loc,INSERT_VALUES, &
x_vec_gbl,ierr)
!By placing code between these two statements, computations
can be
!done while messages are in transition.
call DMLocalToGlobalEnd(da,x_vec_loc,INSERT_VALUES, &
x_vec_gbl,ierr)
return
end subroutine
!> This is the function where reactive transport equations are solved.
subroutine solver_dd_snes_solve_react(ilog,idetail,a_in,b_in, &
x_inout,ia_in,ja_in,nngl_in,itsolv, &
over_flow,rnorm,row_idx_l2pg,col_idx_l2pg, &
b_non_interlaced)
use gen, only : rank, node_idx_l2lg, ittot_rt, &
b_output_matrix, b_enable_output
use solver_snes_function, only : form_initial_guess, &
compute_function, &
compute_jacobian
use petsc_mpi_common, only : petsc_mpi_finalize
implicit none
#include <finclude/petscsys.h>
#include <finclude/petscvec.h>
#include <finclude/petscvec.h90>
#include <finclude/petscdmda.h>
PetscInt :: ilog
PetscInt :: idetail
PetscInt :: nngl_in
PetscReal, allocatable :: a_in(:)
PetscReal, allocatable :: b_in(:)
PetscReal, allocatable :: x_inout(:)
PetscInt, allocatable :: ia_in(:)
PetscInt, allocatable :: ja_in(:)
PetscInt, allocatable :: row_idx_l2pg(:)
PetscInt, allocatable :: col_idx_l2pg(:)
PetscInt :: itsolv
PetscBool :: over_flow
PetscBool :: b_non_interlaced
PetscReal :: rnorm
PetscViewer :: viewer
PetscScalar,pointer :: vecpointer(:)
PetscErrorCode :: ierr
PetscInt :: info_debug
character(72) :: strinum
info_debug = 0
if(b_output_matrix .and. b_enable_output) then
write(strinum, *) ittot_rt
strinum = "_"//trim(adjustl(strinum))
end if
!Form initial guess, only assemble the local owned part,
without ghost nodes
call form_initial_guess(rank,dmda_react%da,x_inout,x_react_loc,&
x_react,nngl_in, row_idx_l2pg,col_idx_l2pg, &
b_non_interlaced)
!Compute function, only assemble the local part, without ghost
nodes
call compute_function(rank,dmda_react%da,b_in,b_react_loc, &
b_react,nngl_in,row_idx_l2pg,col_idx_l2pg, &
b_non_interlaced)
!Compute jacobian matrix, only assemble the local part, without
ghost nodes
call compute_jacobian(rank,dmda_react%da, &
a_react,a_in,ia_in,ja_in,nngl_in, &
row_idx_l2pg,col_idx_l2pg, &
b_non_interlaced)
! Solve a x = b, where a is the Jacobian matrix.
! - First, set the KSP linear operators. Here the matrix that
! defines the linear system also serves as the preconditioning
! matrix.
! - Then solve the Newton system.
#ifdef PETSC_V3_5_X
call KSPSetOperators(ksp_react,a_react,a_react,ierr)
#else
call KSPSetOperators(ksp_react,a_react,a_react, &
SAME_NONZERO_PATTERN,ierr)
#endif
call KSPSetDM(ksp_react,dmda_react%da,ierr)
call KSPSetDMActive(ksp_react,PETSC_FALSE,ierr)
call KSPSolve(ksp_react,b_react,x_react,ierr)
!Get residual norm, by default, preconditioned residual norm is
calculated.
if (b_mykspconverged_react .and. &
.not. b_use_petsc_default_react) then
rnorm = rnorm_react
else
call KSPGetResidualNorm(ksp_react, rnorm, ierr)
end if
! Scatter ghost points to local vector, using the 2-step process
! DMGlobalToLocalBegin(), DMGlobalToLocalEnd().
! By placing code between these two statements, computations
can be
! done while messages are in transition.
call DMGlobalToLocalBegin(dmda_react%da,x_react,INSERT_VALUES, &
x_react_loc,ierr)
call DMGlobalToLocalEnd(dmda_react%da,x_react,INSERT_VALUES, &
x_react_loc,ierr)
call VecGetArrayF90(x_react_loc,vecpointer,ierr)
x_inout = vecpointer
call VecRestoreArrayF90(x_react_loc,vecpointer,ierr)
return
end subroutine
Barry
It is strange why this error does not occur at the first timestep.
Thanks,
Danyang
On Apr 28, 2015, at 7:30 PM, Danyang Su <[email protected]> wrote:
Hi Barry,
There seems another bug (not pretty sure) in PETSc-dev, as shown below. The
case I used is similar with the one I mentioned recently. I have no problem
running this case using PETSc 3.5.2. But it give out the following error using
PETSc-dev, even with only one processor.
Thanks,
Danyang
timestep: 2048 time: 4.615E+00 years delt: 1.460E-20 years iter: 1
max.sia: 0.000E+00 tol.sia: 0.000E+00
[0]PETSC ERROR: --------------------- Error Message
--------------------------------------------------------------
[0]PETSC ERROR: Object is in wrong state
[0]PETSC ERROR: Vec is locked read only, argument # 1
[0]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html for
trouble shooting.
[0]PETSC ERROR: Petsc Development GIT revision: v3.5.3-2796-g23b6c49 GIT Date:
2015-04-27 11:32:44 -0500
[0]PETSC ERROR: ../min3p_thcm on a linux-gnu-dbg named nwmop by dsu Tue Apr 28
15:56:41 2015
[0]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
[0]PETSC ERROR: #349 VecGetArray() line 1646 in
/home/dsu/Soft/PETSc/petsc-dev/src/vec/vec/interface/rvector.c
[0]PETSC ERROR: #350 VecGetArrayPair() line 434 in
/home/dsu/Soft/PETSc/petsc-dev/include/petscvec.h
[0]PETSC ERROR: #351 VecScatterBegin_SSToSS() line 649 in
/home/dsu/Soft/PETSc/petsc-dev/src/vec/vec/utils/vscat.c
[0]PETSC ERROR: #352 VecScatterBegin() line 1694 in
/home/dsu/Soft/PETSc/petsc-dev/src/vec/vec/utils/vscat.c
[0]PETSC ERROR: #353 DMLocalToGlobalBegin_DA() line 56 in
/home/dsu/Soft/PETSc/petsc-dev/src/dm/impls/da/dagtol.c
[0]PETSC ERROR: #354 DMLocalToGlobalBegin() line 1944 in
/home/dsu/Soft/PETSc/petsc-dev/src/dm/interface/dm.c
Reduce time step for reactive transport
no further time step reduction possible
Optimal time increment computed by MIN3P 2.6644769214899893E-018
Minimum time increment specified by user 3.6499999999999998E-018
Please, reduce the MINIMUM TIME INCREMENT
stop signal in time step reduction failed
On 15-04-28 11:15 AM, Barry Smith wrote:
I am forwarding this on to the hypre support email list; hopefully they can
have some advice on how to proceed.
hypre folks, this is with version hypre-2.10.0b (the previous version had
the same behavior). We are getting a divide by zero in gselim() line 4363 (this
happens in a time dependent problem after many successful solves with time
dependent matrix). I looked at the code, below, and note that there are some
checks for the diagonal of A not being zero but not for the line that causes
the divide by zero; is this perhaps an oversight in the hypre code? Any advice
appreciated.
Thanks
Barry
HYPRE_Int gselim(A,x,n)
HYPRE_Real *A;
HYPRE_Real *x;
HYPRE_Int n;
{
HYPRE_Int err_flag = 0;
HYPRE_Int j,k,m;
HYPRE_Real factor;
if (n==1) /* A is 1x1 */
{
if (A[0] != 0.0)
{
x[0] = x[0]/A[0];
return(err_flag);
}
else
{
err_flag = 1;
return(err_flag);
}
}
else /* A is nxn. Forward elimination */
{
for (k = 0; k < n-1; k++)
{
if (A[k*n+k] != 0.0)
{
for (j = k+1; j < n; j++)
{
if (A[j*n+k] != 0.0)
{
factor = A[j*n+k]/A[k*n+k];
for (m = k+1; m < n; m++)
{
A[j*n+m] -= factor * A[k*n+m];
}
/* Elimination step for rhs */
x[j] -= factor * x[k];
}
}
}
}
/* Back Substitution */
for (k = n-1; k > 0; --k)
{
x[k] /= A[k*n+k];
for (j = 0; j < k; j++)
{
if (A[j*n+k] != 0.0)
{
x[j] -= x[k] * A[j*n+k];
}
}
}
x[0] /= A[0];
return(err_flag);
}
}
On Apr 28, 2015, at 12:55 PM, Danyang Su <[email protected]> wrote:
Hi Barry,
The development version of PETSc does not help to solve my problem. It still
crashed due to the same error information.
As Matthew mentioned, I checked the matrix and non of the diagonal entry is
zero. But the diagonal values for different rows range from -1.0d-18 to 1.0d33
and the matrix is not strict diagonal dominant. When using 1 processor, the
matrix is also not strict diagonal dominant, but the diagonal values have a
much smaller range and the codes can run without error. Maybe there is
something wrong in the matrix for this case and I need to check the matrix
first.
Thanks,
Danyang
Program received signal SIGFPE, Arithmetic exception.
0x00007f668c1299d5 in gselim (A=0x2fe3330, x=0x2210680, n=9)
at par_relax.c:4363
4363 x[k] /= A[k*n+k];
(gdb)
[1]PETSC ERROR: *** unknown floating point error occurred ***
[1]PETSC ERROR: The specific exception can be determined by running in a
debugger. When the
[1]PETSC ERROR: debugger traps the signal, the exception can be found with
fetestexcept(0x3d)
[1]PETSC ERROR: where the result is a bitwise OR of the following flags:
[1]PETSC ERROR: FE_INVALID=0x1 FE_DIVBYZERO=0x4 FE_OVERFLOW=0x8
FE_UNDERFLOW=0x10 FE_INEXACT=0x20
[1]PETSC ERROR: Try option -start_in_debugger
[1]PETSC ERROR: likely location of problem given in stack below
[1]PETSC ERROR: --------------------- Stack Frames
------------------------------------
[1]PETSC ERROR: Note: The EXACT line numbers in the stack are not available,
[1]PETSC ERROR: INSTEAD the line number of the start of the function
[1]PETSC ERROR: is given.
[1]PETSC ERROR: [1] PetscDefaultFPTrap line 379
/home/dsu/Soft/PETSc/petsc-dev/src/sys/error/fp.c
[1]PETSC ERROR: [1] Hypre solve line 216
/home/dsu/Soft/PETSc/petsc-dev/src/ksp/pc/impls/hypre/hypre.c
[1]PETSC ERROR: [1] PCApply_HYPRE line 203
/home/dsu/Soft/PETSc/petsc-dev/src/ksp/pc/impls/hypre/hypre.c
[1]PETSC ERROR: [1] PCApply line 430
/home/dsu/Soft/PETSc/petsc-dev/src/ksp/pc/interface/precon.c
[1]PETSC ERROR: [1] KSP_PCApply line 234
/home/dsu/Soft/PETSc/petsc-dev/include/petsc/private/kspimpl.h
[1]PETSC ERROR: [1] KSPInitialResidual line 44
/home/dsu/Soft/PETSc/petsc-dev/src/ksp/ksp/interface/itres.c
[1]PETSC ERROR: [1] KSPSolve_GMRES line 224
/home/dsu/Soft/PETSc/petsc-dev/src/ksp/ksp/impls/gmres/gmres.c
[1]PETSC ERROR: [1] KSPSolve line 506
/home/dsu/Soft/PETSc/petsc-dev/src/ksp/ksp/interface/itfunc.c
[1]PETSC ERROR: User provided function() line 0 in Unknown file trapped
floating point error
On 15-04-27 11:47 AM, Barry Smith wrote:
Danyang,
I'm glad you were finally able to get to the problematic point; sorry it
took so long (I want to strangle whoever turned on catching of underflows in
PETSc).
The hypre folks have done a great deal of work on their relaxation code
since the PETSc 3.5.3 release. There is a good chance they have fixed the
divide by zero problem you are hitting here. You will need to upgrade to the
development version of PETSc (that uses the latest version of hypre), here are
the instructions on how to obtain it
http://www.mcs.anl.gov/petsc/developers/index.html
Please let us know if this resolves the problem with hypre failing.
Barry
On Apr 27, 2015, at 11:44 AM, Danyang Su <[email protected]> wrote:
Hi Barry,
I got the following arithemetic exception after the previous bug is fixed.
Loaded symbols for /lib/x86_64-linux-gnu/libnss_files.so.2
0x00007f3b23b98f20 in __nanosleep_nocancel ()
at ../sysdeps/unix/syscall-template.S:81
81 ../sysdeps/unix/syscall-template.S: No such file or directory.
(gdb) cont
Continuing.
Program received signal SIGFPE, Arithmetic exception.
0x00007f3b260df449 in gselim (A=0x1e4c580, x=0x1d30c40, n=9)
at par_relax.c:3442
3442 x[k] /= A[k*n+k];
(gdb)
I tried both PETSc 3.5.2 and 3.5.3 and they return the same error as shown
above. For 3.5.3, i edited fp.c file and then configure and make.
Thanks,
Danyang
On 15-04-25 07:34 PM, Danyang Su wrote:
Hi All,
The "floating point underflow" is caused by a small value divided by a very
large value. This result is forced to zero and then it does not report any underflow
problem. I just rerun this bad case to see if it still get stuck later. This will take a
while.
Thanks for all your kindly reply,
Danyang
On 15-04-25 07:02 PM, Barry Smith wrote:
Ok, you do have
#ifndef PETSC_HAVE_XMMINTRIN_H
#define PETSC_HAVE_XMMINTRIN_H 1
#endif
so the change you made should cause it to stop trapping underflow exceptions.
Now in one email you reported a FPE within hypre, then I asked you to run
with -start_in_debugger to determine where it happened exactly and then you
reported the FPE happened in user code (what seemed to be an underflow issue).
Why is this? Can you not run it where it generated the FPE in hypre using the
-start_in_debugger option?
Barry
Perhaps you have multiple PETSC_ARCH or multiple PETSc installs to explain why
you reported two different places where the exception occurred.
On Apr 25, 2015, at 8:31 PM, Danyang Su <[email protected]> wrote:
On 15-04-25 06:26 PM, Matthew Knepley wrote:
On Sat, Apr 25, 2015 at 8:23 PM, Danyang Su <[email protected]> wrote:
On 15-04-25 06:03 PM, Barry Smith wrote:
If this is what you got in your last run
at ../../gas_advection/velocity_g.F90:1344
1344 cinfrt = cinfrt_dg(i1) *
diff(ic,idim) !diff is a very small value,
e.g., 1.0d-316
then it is still catching floating point underflow, which we do not want.
This means either the change I suggested you make in the fp.c code didn't work
or it actually uses a different floating point trap than that one. BTW: absurd
numbers like 1.0d-316 are often a symptom of uninitialized data; could that be
a problem that diff is not filled correctly for all the ic, idim you are using?
This going round and round is very frustrating and a waste of time. You
need to be more proactive yourself and explore the code and poke around to
figure out how to solve the problem.
Please email $PETSC_DIR/$PETSC_ARCH/include/petscvariables.h so I can see
what FP trap is being used on your machine.
Barry
Do you mean $PETSC_DIR/$PETSC_ARCH/conf/petscvariables? Otherwise I cannot find
this file.
Its include/petscconf.h
Do I need to reconfigure PETSc after changing the code you mentioned?
No, but you need to rebuild.
Yes, I have done 'gnumake'.
Matt
Danyang
On Apr 25, 2015, at 2:24 PM, Danyang Su <[email protected]> wrote:
On 15-04-25 11:55 AM, Barry Smith wrote:
On Apr 25, 2015, at 1:51 PM, Danyang Su <[email protected]>
wrote:
On 15-04-25 11:32 AM, Barry Smith wrote:
I told you this yesterday.
It is probably stopping here on a harmless underflow. You need to edit the
PETSc code to not worry about underflow.
Edit the file /home/dsu/Soft/PETSc/petsc-3.5.2/src/sys/error/fp.c and locate
#elif defined PETSC_HAVE_XMMINTRIN_H
_MM_SET_EXCEPTION_MASK(_MM_MASK_INEXACT);
#else
change it to
#elif defined PETSC_HAVE_XMMINTRIN_H
_MM_SET_EXCEPTION_MASK(_MM_MASK_INEXACT | _MM_MASK_UNDERFLOW);
#else
Then run make gnumake in the PETSc directory to compile the new version. Now
link and run the program again with -fp_trap and see where it gets stuck this
time.
Did you do this?
Barry
Yes, I did change the code in fp.c and run 'make gnumake' in the PETSc
directory. I just did a double check and ran make gnumake again and got the
following information this time.
dsu@nwmop:~/Soft/PETSc/petsc-3.5.2$
make gnumake
Building PETSc using GNU Make with 10 build threads
==========================================
make[1]: Entering directory `/home/dsu/Soft/PETSc/petsc-3.5.2'
make[1]: Nothing to be done for `all'.
make[1]: Leaving directory `/home/dsu/Soft/PETSc/petsc-3.5.2'
=========================================
Then I recompiled the codes, ran with -fp_trap and still got the following error
Backtrace for this error:
Note: The EXACT line numbers in the stack are not available,
[2]PETSC ERROR: INSTEAD the line number of the start of the function
[2]PETSC ERROR: is given.
[2]PETSC ERROR: [2] PetscDefaultFPTrap line 379
/home/dsu/Soft/PETSc/petsc-3.5.2/src/sys/error/fp.c
INSTEAD the line number of the start of the function
[3]PETSC ERROR: is given.
[3]PETSC ERROR: [3] PetscDefaultFPTrap line 379
/home/dsu/Soft/PETSc/petsc-3.5.2/src/sys/error/fp.c
[2]PETSC ERROR: User provided function() line 0 in Unknown file trapped
floating point error
[3]PETSC ERROR: User provided function() line 0 in Unknown file trapped
floating point error
This is different then what you sent a few minutes ago where it crashed in
hypre.
Anyways you need to use the -start_in_debugger business I sent in the
previous email to see the exact place the problem occurs.
Here is the information shown on gdb screen
Program received signal SIGFPE, Arithmetic exception.
0x00000000006c2bef in velocity_g (l_sufx=1, suffix=..., nmax=12, njamxc=34,
cinfradx=..., radial_coordx=.FALSE., _suffix=3)
at ../../gas_advection/velocity_g.F90:1344
1344 cinfrt = cinfrt_dg(i1) *
diff(ic,idim) !diff is a very small value,
e.g., 1.0d-316
(gdb)
After type cont on gdb screen, I got error information as below
[1]PETSC ERROR: *** unknown floating point error occurred ***
[1]PETSC ERROR: The specific exception can be determined by running in a
debugger. When the
[1]PETSC ERROR: debugger traps the signal, the exception can be found with
fetestexcept(0x3d)
[1]PETSC ERROR: where the result is a bitwise OR of the following flags:
[1]PETSC ERROR: FE_INVALID=0x1 FE_DIVBYZERO=0x4 FE_OVERFLOW=0x8
FE_UNDERFLOW=0x10 FE_INEXACT=0x20
[1]PETSC ERROR: Try option -start_in_debugger
[1]PETSC ERROR: likely location of problem given in stack below
[1]PETSC ERROR: --------------------- Stack Frames
------------------------------------
[1]PETSC ERROR: Note: The EXACT line numbers in the stack are not available,
[1]PETSC ERROR: INSTEAD the line number of the start of the function
[1]PETSC ERROR: is given.
[1]PETSC ERROR: [1] PetscDefaultFPTrap line 379
/home/dsu/Soft/PETSc/petsc-3.5.2/src/sys/error/fp.c
[1]PETSC ERROR: User provided function() line 0 in Unknown file trapped
floating point 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
Thanks,
Danyang
Thanks,
Danyang
On Apr 25, 2015, at 1:05 AM, Danyang Su <[email protected]>
wrote:
Hi Barry and Satish,
How can I get rid of unknown floating point error when a very small value is
multiplied.
e.g.,
cinfrt_dg(i1) and diff(ic,idim) are 1.0250235986806329E-008
8.6178408169776945E-317 respectively,
cinfrt = cinfrt_dg(i1) * diff(ic,idim)
I get the following error when run with "-fp_trap -start_in_debugger".
Backtrace for this error:
*** unknown floating point error occurred ***
[2]PETSC ERROR: The specific exception can be determined by running in a
debugger. When the
[2]PETSC ERROR: debugger traps the signal, the exception can be found with
fetestexcept(0x3d)
[2]PETSC ERROR: cinfrt_dg(i1),diff(ic,idim) 1.0250235986806329E-008
8.6178408169776945E-317
where the result is a bitwise OR of the following flags:
[2]PETSC ERROR: FE_INVALID=0x1 FE_DIVBYZERO=0x4 FE_OVERFLOW=0x8
FE_UNDERFLOW=0x10 FE_INEXACT=0x20
[2]PETSC ERROR: Try option -start_in_debugger
[2]PETSC ERROR: likely location of problem given in stack below
Thanks,
Danyang
On 15-04-24 01:54 PM, Danyang Su wrote:
On 15-04-24 01:23 PM, Satish Balay wrote:
c 4 1.0976214263087059E-067
I don't think this number can be stored in a real*4.
Satish
Thanks, Satish. It is caused by this number.
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
--
What most experimenters take for granted before they begin their experiments is
infinitely more interesting than any results to which their experiments lead.
-- Norbert Wiener
<petscconf.h>
