[petsc-users] MPI Communication times

[Manuel Valera via petsc-users]

Hello,

I am working on timing my model, which we made MPI scalable using petsc
DMDAs, i want to know more about the output log and how to calculate a
total communication times for my runs, so far i see we have "MPI Messages"
and "MPI Messages Lengths" in the log, along VecScatterEnd and
VecScatterBegin reports.

My question is, how do i interpret these number to get a rough estimate on
how much overhead we have just from MPI communications times in my model
runs?

Thanks,