XMPI EXAMPLE

        How to start XMPI

        "wave1d" is a simple example of SPMD grid parallel programming technique, written in Fortran.  It runs with any number of processes, up to the number of arbitrarily chosen grid points. The resulting wave.out files should be concatenated in ascending process order to form the complete wave data.

           The commands which follow allow to start XMPI in the good order. "ex_wave" is the executable file and "wave.lamtr" is a trace data file we create. To generate a trace by process,  use option -t lors du lancement du programme par la commande mpirun "h" is the machine name file  or inventory of nodes file. "nb_procs" is the number of procs which represents the virtual machine.

                        > lamboot  -v  h
                        > mpirun -t -np nb-procs ex_wave     (To generate a trace by process,  use option -t )
                        > lamtrace -mpi  wave.lamtr
                        > xmpi h
 
 

Application Overview






        To load and view an existing trace file select the "View" item in the "Trace" menu. The trace file "wave.lamtr" is represented by the following window, with 6 process :

Communication Timeline








         Focusing on a process :  More information on a process's state can be obtained by clicking the left mouse button within the process hexagon. This will pop up a focus window. The upper area of the focus window is the process area and displays the current state of the process. The lower area is the message area and displays information on the process's queue.
 
 


 









        Message Source Matrix :  The message source window displays a square matrix of process message. For each process it shows the number of queued messages from each other process in the application. It can be brought up while monitoring a running application or while viewing a trace file, by selecting the "Matrix" button or "Matrix" item in the "Trace" menu.

        Kiviat Window :   When viewing a trace file, the "Kiviat" button or  "Kiviat" item in the "Trace" menu brings up the Kiviat window. This window displays the cumulative time up to the current dial time, spent by each process in the running, overhead and blocked states.
 
 

                            
      Matrix: Unreceived messages counted by source rank            Kiviat: Process states are cumulative
                                                                                                                                               from the start to the dial time
 

        All user processes and messages can be removed, without rebooting with the following command :

                           > lamclean -v

        The wipe tool removes all traces of the LAM session on the network. This is only performed when LAM is no longer needed.

                           > wipe -v h
 
 


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