The main benefit the MultiProcessing Environment library (mpe) offers is a set
of routines that will create logfiles from MPI programs which can be examined
by Jumpshot or upshot.  These logfiles can be created manually by inserting
calls to mpe routines in your code, automatically by linking with the
appropriate MPE libraries, or by combining the two methods.  Currently, the
mpe library offers 3 profiling libraries.
 
        1) Tracing Library - Trace all MPI calls.  Each MPI call is preceded
by a line that contains the rank in MPI_COMM_WORLD of the calling process, and
followed by another line indicating that the call has completed.  Most send
and receive routines also indicate the values of count, tag, and partner
(destination for sends, source for receives).  Output is to standard output.
 
        2)  Animation Library - This is a simple form of real-time program
animation and requires X window routines.
 
        3)  Logging Library - This is the most useful profiling library and
is the most widely used.  Logfiles (files of timestamped events) are generated
and can be analyzed with graphical tools such as Jumpshot (preferrably) or
upshot.