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

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

Yes that's true. I'll discuss with the other developers how this can be improved. Also we're working on a fix to avoid the SEGFAULT.

Stefan


On Apr 9, 2010, at 6:05 PM, nek5000-users at lists.mcs.anl.gov wrote:

> 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
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>> 
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