[Nek5000-users] Seg. fault in running a backward facing step case.

[nek5000-users at lists.mcs.anl.gov]

Hi Stefan,

Thanks for your reply. Compiling with with a larger lelt and OIFS on the code worked.

So what I understand from your reply is that if OIFS is ON the code requires more memory
and it should be compiled with more lelt rather than the exact lelt=lelg/lp.

Harish.


On Fri, 9 Apr 2010 nek5000-users at lists.mcs.anl.gov wrote:

> Harish,
>
> when we try to exit the code with an error message the code crashes. You turned on OIFS (T IFCHAR) but you don't have enough memory available. I think you can just increase lelt to avoid this problem. Anyway the code should print out a reasonable err-msg and not a SEGFAULT!
>
>
> Stefan
>
>
>
> On Apr 9, 2010, at 4:33 PM, nek5000-users at lists.mcs.anl.gov wrote:
>
> > Hello,
> >
> > I am trying to simulate flow in a 3D backward facing step (BFS) geometry.
> >
> > I have attached the *.box file and n2to3.in file that I use to create the
> > 3D geometry. For reference logfile, *.rea and *.usr files are attached.
> > The code is compiled with GNU compiler and OpenMPI. The code is compiled
> > for 16 processors and compiler.out file is attached as well.
> >
> > When I run the code, I get a seg. fault. After running the "gdb" tool on
> > the core.* file, I get the following output. I have attached the gdb
> > output file too.
> > ===========================================================================
> > Core was generated by `./nek5000'.
> > Program terminated with signal 11, Segmentation fault.
> > [New process 7652]
> > #0  0x0000000000488768 in chcopy_ ()
> > ===========================================================================
> >
> > 3D BFS geometry has a wall at the bottom and symmetry b.c. at the top. But
> > if I change the top b.c. with wall the simulation works. For reference I
> > have attached the job output file.
> >
> > Initially, I thought the problem was with memory limitations on my cluster
> > for a bigger geometry. So I tried a smaller geometry, but I still kept
> > getting seg. faults.
> >
> > Help with solving this problem will be greatly appreciated. And sorry for
> > attaching so many files.
> >
> > Thanks,
> >
> > Harish.<bfs.box><n2to3.in><logfile><bfs3d.rea><bfs3d.usr><Backstp.2323.o><gdb.output><compiler.out>_______________________________________________
> > Nek5000-users mailing list
> > Nek5000-users at lists.mcs.anl.gov
> > https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
>
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