Global Reduction of Time Stepping Data

I currently do the following to reduce and broadcast global values, like e.g. the minimum time step size:

• I broadcast time step data from master to worker all the way down to the "lowest" worker.
• I reduce time step data from worker to master all the way up to the global master rank.

I could use a simple MPI_Reduce and a simple MPI_Gather to perform the above steps.~~

Postponed.