hi Matthew, Jed Thank you very much for the answer and advise.
Cong On Fri, Aug 16, 2013 at 10:18 PM, Jed Brown <[email protected]> wrote: > Matthew Knepley <[email protected]> writes: > > Never put in a barrier. > > Barriers serve no functional or correctness purpose in a > properly-written pure-MPI code. They are sometimes useful for debugging > and sometimes necessary if you use despicable hacks like communicating > through a side channel such as the file system. If you're not putting > yourself into that unenviable position, don't use barriers. >
