Centre Blaise Pascal » Bench4GPU

#!/usr/bin/env python

#

# PiMC model using mpi4py MPI implementation for Python

#

# CC BY-NC-SA 2011 : <emmanuel.quemener@ens-lyon.fr> 

#

# Thanks to Lisandro Dalcin for MPI4PY :

# http://mpi4py.scipy.org/

import sys

from math import exp

from random import random

import time

# MPI librairie call

import mpi4py

from mpi4py import MPI

def MainLoop(iterations):

    total=0

    for i in xrange(iterations):

        # Random access coordonate

        x,y=random(),random()

        if ((x*x+y*y) < 1.0):

                total+=1

    return(total)

if __name__=='__main__':

   # MPI Init

   comm = MPI.COMM_WORLD

   rank = comm.Get_rank()

   # Define number of Nodes on with computing is performed (exclude 0)

   NODES=comm.Get_size()

   # Au dessus de 4 10^7, le MPI ne veut plus se lancer...

   Iterations=1000000000

   # pass explicit MPI datatypes

   total=0

   if rank == 0:

           # Define iterations to send to each node

           if Iterations%NODES==0:

                   iterations=Iterations/NODES

           else:

                   iterations=Iterations/NODES+1

           print "%i iterations will be send to each node" % iterations

           for i in range(1,NODES):

                   print "Send from 0 to node %i" % i

                   ToSend=iterations

                   # Send MPI call to each node

                   comm.send(ToSend, dest=i, tag=11)

           # Master does part of job !

           total=MainLoop(iterations)

           print "Partial Result from master %i: %i" % (rank,total)

           print "Retreive results..."

           for i in range(1,NODES):

                   # Receive MPI call from each node

                   Output=comm.recv(source=i,tag=11)

                   print "Partial Result from %i: %s" % (i,Output)

                   total+=Output

           print "Global Result: %i" % (total)

   else:

           # Slave applies simulation to set provided by master

           # Receive MPI call with Input set

           ToReceive=comm.recv(source=0, tag=11)

           iterations=ToReceive

           print "Rank %i receives with job with %i" % (rank,iterations) 

           Output=MainLoop(iterations)

           comm.send(Output, dest=0, tag=11)