dolfin team mailing list archive

["Garth N. Wells" <gnw20@xxxxxxxxx>]

Anders Logg wrote:
> On Wed, Aug 13, 2008 at 08:03:39PM +0100, Garth N. Wells wrote:
> > I'm experiencing a puzzling problem wth pyDOLFIN and MPI again.
> >
> > When I do
> >
> >      python file.py
> >
> > where file.py is just
> >
> >      from dolfin import *
> >
> >      object = Function("/tmp/fileKFnQpl.xml")
> >      plot(object)
> >      interactive()
> >
> > I see a plot as expected, and get
> >
> >      Plot active, press 'q' to continue.
> >
> > After pressing 'q', I get
> >
> >      *** An error occurred in MPI_Attr_get
> >      *** after MPI was finalized
> >      *** MPI_ERRORS_ARE_FATAL (goodbye)
> >      [gnw20pc:2277] Abort before MPI_INIT completed successfully; not 
> > able to guarantee that all other processes were killed!
> >      *** An error occurred in MPI_Comm_rank
> >      *** after MPI was finalized
> >      *** MPI_ERRORS_ARE_FATAL (goodbye)
> >      *** An error occurred in MPI_Type_free
> >      *** after MPI was finalized
> >      *** MPI_ERRORS_ARE_FATAL (goodbye)
> >      Segmentation fault
> >
> > Somehow, Python appears to be calling MPI_Finalize before DOLFIN gets a 
> > chance to finalise things correctly. Any ideas/experience on how Python 
> > interacts with MPI? I've commented out MPI_Finalize() in DOLFIN to be 
> > sure that DOLFIN is not calling it.
> >
> > Garth
>
> Would it help if we just call MPI_Finalized to check before
> finalizing? 

No, because something is killing MPI before PETSc is finished.

What I don't understand is what an MPI-enable library does when wrapped 
and called from Python.

Garth

We can add a wrapper for it just like for MPI_Initialized.
> ------------------------------------------------------------------------
>
> _______________________________________________
> DOLFIN-dev mailing list
> DOLFIN-dev@xxxxxxxxxx
> http://www.fenics.org/mailman/listinfo/dolfin-dev