[petsc-users] Segmentation error when calling PetscBarrier

[Satish Balay]

verylikely valgrind will find bugs in code..

http://www.mcs.anl.gov/petsc/documentation/faq.html#valgrind

> When the X-window appears, the code has already exited

try --debugger_pause 60 [or higher if it takes longer to swawn the xterms]

Satish


On Mon, 4 Jan 2016, Barry Smith wrote:

> 
>   You could try instead -on_error_attach_debugger and see if that is better at catching the code when the error occurs
> 
>    If the code runs valgrind clean (when it runs) then I would say it is reasonable for you to conclude that the current trouble is due to a Intel optimization error and not debug further,
> 
>   Barry
> 
> > On Jan 4, 2016, at 9:34 PM, TAY wee-beng <zonexo at gmail.com> wrote:
> > 
> > Hi,
> > 
> > Ya sorry, that should be the tool to use. Was having some problems using MPI with the debugger.
> > 
> > I managed to run it as a serial code now.
> > 
> > My problem is that on the cluster, it works with the gnu fortran. But using Intel compiler, I get segmentation error at some point when running the opt ver. The debug ver works fine.
> > 
> > I am trying to find if the error is due to a bug in Intel, or it's my own problem.
> > 
> > Another thing is that on another cluster, the Intel opt ver works, but that's using a newer ver of the compiler.
> > 
> > I hope to get the Intel one working if possible, because it's about 30% faster.
> > 
> > So now coming back to the gdb, it worked fine using the debug ver of the code. But when using the opt ver, it only shows segmentation fault. When the X-window appears, the code has already exited. I am already using -g during compile.
> > 
> > So how should I debug it? The error seems to be when I tried to call DMDAVecRestoreArrayF90, although I still need to be more certain.
> > 
> > 
> > Thank you
> > 
> > Yours sincerely,
> > 
> > TAY wee-beng
> > 
> > On 5/1/2016 10:32 AM, Barry Smith wrote:
> >>   You are missing the ,ierr which BTW you would have caught immediately if you used the debugger.
> >> 
> >>   Barry
> >> 
> >>   The debugger is not a scary monster, it is one of your best friends.
> >> 
> >>> On Jan 4, 2016, at 7:28 PM, TAY wee-beng <zonexo at gmail.com> wrote:
> >>> 
> >>> Hi,
> >>> 
> >>> I am trying to debug my CFD Fortran MPI code. I tried to add:
> >>> 
> >>> call PetscBarrier(PETSC_NULL_OBJECT); if (myid==0) print *, "xx"
> >>> 
> >>> to do a rough check on where the error is. xx is a different number for each line.
> >>> 
> >>> I found that whenever I add this line, the code aborts with segmentation error.
> >>> 
> >>> I am using the Intel compiler. Is there any error with my usage?
> >>> 
> >>> -- 
> >>> Thank you
> >>> 
> >>> Yours sincerely,
> >>> 
> >>> TAY wee-beng
> >>> 
> > 
> 
>