[Dune] ALUGrid loadbalance

[Jö Fahlke]

Am Thu,  2. Jul 2015, 16:04:01 +0100 schrieb Andreas Dedner:
> Date: Thu, 2 Jul 2015 16:04:01 +0100
> From: Andreas Dedner <a.s.dedner at warwick.ac.uk>
> To: dune at dune-project.org
> Subject: Re: [Dune] ALUGrid loadbalance
> 
> Hi.
> Looks weird - a bit of increase is expected due to the ghost elements but
> not to that extend.
> Have you simply taken a look at the resulting partitioned grid in paraview?
> Andreas

If you do, note that the VTKWriter usually only outputs interior elements in
each rank.  You can probably get it to output ghosts as well if you
temporarily change VTK_Partition to All_Partition, see
https://cgit.dune-project.org/repositories/dune-grid/tree/dune/grid/io/file/vtk/vtkwriter.hh#n81

Regards,
Jö.

> On 02/07/15 16:00, Arya Fallahi wrote:
> >Dear Dune,
> >
> >Sometime ago I upgraded my alugrid and started using the one integrated
> >into dune library, namely dune-alugrid. I was always suffering from slow
> >computation time that I suddenly realized today that something is going
> >wrong with my load balancing. In the following, I am sending you an
> >example of what I do in my code:
> >
> >typedef GridSelector::GridType Grid;
> >
> >MPI_Init(&argc,&argv);
> >MPI_Comm_rank(MPI_COMM_WORLD,&rank);
> >MPI_Comm_size(MPI_COMM_WORLD,&size);
> >
> >GridPtr<Grid> ag ( "./grid1.dgf" , MPI_COMM_WORLD );
> >Grid& g = *ag;
> >g.loadBalance();
> >typedef LeafMultipleCodimMultipleGeomTypeMapper<Grid,P0Layout> emap;
> >emap em(g);
> >std::cout << em.size() << std::endl;
> >
> >Without load balancing I get the following output on 4 processors:
> >
> >0
> >0
> >0
> >15468
> >
> >meaning that the grid has 15648 elements. However, with load balancing I
> >get the following output:
> >
> >11235
> >11869
> >12906
> >11244
> >
> >It seems that the total number of elements are getting considerably
> >higher. Do you have any guess what I am doing wrong?
> >
> >Thank you very much for your help,
> >Arya
> >
> >
> >_______________________________________________
> >Dune mailing list
> >Dune at dune-project.org
> >http://lists.dune-project.org/mailman/listinfo/dune
> 

> _______________________________________________
> Dune mailing list
> Dune at dune-project.org
> http://lists.dune-project.org/mailman/listinfo/dune


-- 
Jorrit (Jö) Fahlke, Institute for Computational und Applied Mathematics,
University of Münster, Orleans-Ring 10, D-48149 Münster
Tel: +49 251 83 35146 Fax: +49 251 83 32729

Of all the things I've lost, I miss my mind the most.
-- Ozzy Osbourne
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 811 bytes
Desc: Digital signature
URL: <https://lists.dune-project.org/pipermail/dune/attachments/20150702/080716c3/attachment.sig>