[Dune] parallel DUNE grid for implementing a spherical shell (UGGrid)

[Markus Blatt]

Hey Eike,

On Mon, Nov 05, 2012 at 07:17:48PM +0000, Eike Mueller wrote:
> > 
> > And loadbalancing would only be needed for the macrogrid, e.g., not dynamic.
> > 
> 
> That's right, in the code I would refine the grid until there is
> only cell per processor (this is the macrogrid). Then I would call
> loadBalance, followed by further grid refinement. So for example
> with 24 processors, I would subdivide each of the six cells in the
> original grid into four cells, then loadbalance that grid and refine
> further. 

Actually, this approach could be the root of the problem. The
loadbalancing is a heuristic algorithm and normally one always gets
some load imbalance here. But if you just have as many cells as
processor, then naturally some will end up with no cells at all.

How about doing some more refinement before load balancing?

Cheers,

Markus

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