title: What if one process in a MPI program proceeds more slowly than others?
body: <p>Say you have a MPI program where one process has more work to do than other processes. For example, the root process performs an extra function that other processes don't. </p>
  
  <p>Will the program automagically wait for the root process to finish its extra function, before proceeding with other processes? Or will the root process start lagging behind other processes?</p>