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

Fri Apr 9 12:12:09 CDT 2010

Hi Stefan,

Thanks for all your help. I will download the latest release and test it.

Thanks,

Harish

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

> Ok I have just fixed the SEGFAULT in the latest release.
>
> Stefan
>
>
> On Apr 9, 2010, at 6:30 PM, nek5000-users at lists.mcs.anl.gov wrote:
>
> > For the moment you're ok if:
> >
> > TORDER=2, LORDER=3, LELT=NELT/NP + 1
> > TORDER=2, LORDER=3, LELT= (3/2) * NELT/NP + 1
> > TORDER=3, LORDER=3, LELT= (4/3) * NELT/NP + 1
> >
> > hth,
> > Stefan
> >
> > On Apr 9, 2010, at 6:12 PM, nek5000-users at lists.mcs.anl.gov wrote:
> >
> >> Thanks for the help!!
> >>
> >> Harish
> >>
> >> On Fri, 9 Apr 2010 nek5000-users at lists.mcs.anl.gov wrote:
> >>
> >>> 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
> >>>>>> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
> >>>>>
> >>>>> _______________________________________________
> >>>>> Nek5000-users mailing list
> >>>>> Nek5000-users at lists.mcs.anl.gov
> >>>>> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
> >>>>>
> >>>> _______________________________________________
> >>>> Nek5000-users mailing list
> >>>> Nek5000-users at lists.mcs.anl.gov
> >>>> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
> >>>
> >>> _______________________________________________
> >>> Nek5000-users mailing list
> >>> Nek5000-users at lists.mcs.anl.gov
> >>> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
> >>>
> >> _______________________________________________
> >> Nek5000-users mailing list
> >> Nek5000-users at lists.mcs.anl.gov
> >> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
> >
> > _______________________________________________
> > Nek5000-users mailing list
> > Nek5000-users at lists.mcs.anl.gov
> > https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
>
> _______________________________________________
> Nek5000-users mailing list
> Nek5000-users at lists.mcs.anl.gov
> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
>