Carpet has a group of grid scalars for timing information. It would be useful to have a similar group for memory usage and grid size statistics. For example, I would very much like to be able to output the total number of grid points in the simulation, to see if a memory usage increase was related to the total number of grid points increasing, or to something else.
It might also be useful to have this information available per process, so that the usual reductions could be applied on output. This would give a measure of memory imbalance.