> On 19 Mar 2021, at 15:20, Jed Brown <[email protected]> wrote:
>
>> I guess the only issue is now one needs to always remember to traverse cells
>> in the reordered_cells order (although if you call DMPlexPermute that is
>> automatic?).
>
> Can DMPlexPermute handle a non-stratified permutation?
I think the answer here is still no (as per your previous statement). The way
we work around this in Firedrake is as I described above. Effectively we always
traverse the cells in order specified by the RCM reordering. For traversal of
facets and other entities we then build a traversal order once by traversing
the cells and greedily ordering the facets/edges/etc...
I think you could get this behaviour from dmplexpermute if one wrote it so that
it permutes the cells with RCM and then compatibly permutes lower-dimensional
entities. This would maintain stratification, but I think keep good cache
locality for all entity traversals. But I do not understand the details of what
dmplexpermute is doing at the moment.
Cheers,
Lawrence
