[Users] Problem with CarpetRegrid2/AMR

[Hal Finkel]

Erik,

Thanks! This seems to fix the problem. I'll do some more testing
tomorrow.

 -Hal

P.S. The next thing that I need is to get the periodic boundary
conditions working with Carpet. I'll open a ticket for that.

On Wed, 2011-09-14 at 21:41 -0400, Erik Schnetter wrote:
> Hal
> 
> I believe I found the cause; I am attaching a patch. Could you try the
> patch and see whether it works? Unfortunately I have other, unrelated
> changes in my source tree as well.
> 
> The problem is the mapping from component number to process number.
> This mapping may change during regridding. Carpet always used the
> mapping of the current grid structure, and never used the mapping from
> the previous grid structure, and this can lead to failure during
> regridding.
> 
> It boggles my mind that such a problem would not manifest itself
> itself in other simulations as well, either leading to catastrophic
> errors in simulations or in outright crashes. I assume that the reason
> is that all other simulations have many fewer components than you, and
> the mapping is thus trivial and never changes, so that this error is
> not triggered.
> 
> -erik
> 

-- 
Hal Finkel
Postdoctoral Appointee
Leadership Computing Facility
Argonne National Laboratory
1-630-252-0023
hfinkel at anl.gov