Assigning masked tiles to one mpi task

[blaupole]

Hi,
this might be a question that has been asked many times but browsing/searching the forum I could not really spot anything related.

In my application I have many tiles that sit entirely over land. As there shouldn't be much computation load on masked grid points would it be possible to assign all those tiles to one mpi task that manages them ?
The internal logic may not allow this as the number of tiles must equal the number of mpi processes. I could also see that memory becomes a problem for that 'dummy' mpi task as it would have to maintain multiple tiles of the fields.
I know Mark Hadfield used to manually decompose his domains and assign them to mpi tasks.

Any thoughts?

I understand this probably sparks the question why I would use such a wasteful grid configuration. Happy to elaborate on this but it is needed.

Thank you
Stefan

[m.hadfield]

You've probably misunderstood something I wrote: I'm not smart enough to manually assign MPI processes.

Good luck, Stefan. I too work with grids with ridiculously large fractions (~50%) of tiles masked. In principle one could avoid this with composed grids.