CSCI-4320/6340 Assignment 1: Message Passing
Interface
Christopher D. Carothers
Department of Computer Science
Rensselaer Polytechnic Institute
110 8th Street
Troy, New York U.S.A. 12180-3590
January 23, 2009
DUE DATE: 12 p.m/Noon, Friday, February 6th
1 Description
For this assignment you will creating a timing test program for MPI. In particular, you will write
a series of functions where each function will determine the MAX average,MIN average and
AVERAGE average execution time in microseconds of a particular MPI routine across all the
MPI tasks, where each MPI tasks would have excercised a particular MPI call in a loop, Ltimes.
The following routines (or pairs of routines) are the ones you must measure the performance of for
this assignment.
•MPI Send and MPI recv: Here, you will pair-up the MPI tasks according the following
pattern, Rank 0 pars with Rank N−1, Rank 1 pairs with Rank N−2, Rank 2 pairs with
Rank N−3and so on until Rank N/2−1pairs with Rank N/2. In a loop, each pairs of
tasks will first send a message of size M, where Mis an input parameter and then receive
the message that the other task just sent. The loop with integrate Ltimes (where Lis also
an input parameter). You will time the whole loop, compute the local average time and then
determine across all processors the MAX average, MIN average and AVERAGE average
cycle times. I will give you the cycle timer code for an x86 system. The MAX, MIN and
AVERAGE can be computed by doing a MPI Allreduce.
•MPI Isend and MPI Irecv: Do the same as you did for the previous MPI Send and MPI Recv.
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