> On May 29, 2015, at 2:56 PM, Jed Brown <[email protected]> wrote: > > Mark Adams <[email protected]> writes: >> Yea, I realized that VecAssembly should see this load imbalance unless it >> had a barrier before its timer. So I'm not sure what is going on. > > Since you don't have any outgoing entries, I think the huge > MPI_Allreduce is expensive. No surprise.
This explanation matches the known information.
