Intergroup Allgather and Allgatherv Implemented Using MPI functions

The program ./allgather_test runs the intergroup all-to-all broadcast in a loop. The number of iterations can be set by the command-line option -n. The default is 10.

• Compile command:

  • Edit file (Makefile to customize the C compiler and compile options.
  • Run command make to compile and generate the executable program named allgather_test.

• Run command:

  • Command-line options:

      % ./allgather_test -h
    Usage: ./allgather_test [OPTION]... [FILE]...
           [-h] Print help
           [-s] number of MPI processes in group A
           [-r] number of MPI processes in group B
           [-a] message count per process in group A
           [-b] message count per process in group B
           [-d] message block unit size
           [-n] number of trials for the experiments
           [-p] only significant for Allgatherv (when t = 3, 4)
    	   0: regular message distribution
    	   1: irregular message distribution
           [-t] which evaluation
    	   0: Intergroup Allgather with native MPI library
    	   1: Intergroup Allgather with algorithm 2 of EuroMPI paper
    	   2: Intergroup Allgather with algorithm 1 of PARCO paper
    	   3: Intergroup Allgatherv with native MPI library
    	   4: Intergroup Allgather with algorithm 2 of PARCO paper
    

• Example outputs on screen

  • Suppose we have 10 processes in group A and 22 processes in group B. Every process in group A sends 15 data blocks to group B and every process in group B sends 20 data blocks to group A. Every data block has 11 integers. We want to evaluate Algorithm 2 proposed in PARCO paper with 5 iterations.

    % mpiexec -n 32 ./allgather_test -a 15 -b 20 -s 10 -r 22 -d 11 -p 0 -t 4 -n 5
    n_senders=10,n_receivers=22,dim_x=11,size1=10,size2=20,method=4,pattern=0
    Universal full duplex allgatherv time=0.059017(message size time)+0.037100(intergroup message transfer)+0.066018(intragroup allgather)=0.162135
    Universal full duplex allgatherv time=0.036167(message size time)+0.020993(intergroup message transfer)+0.039993(intragroup allgather)=0.097153
    Universal full duplex allgatherv time=0.041959(message size time)+0.021000(intergroup message transfer)+0.039992(intragroup allgather)=0.102951
    Universal full duplex allgatherv time=0.042807(message size time)+0.021071(intergroup message transfer)+0.054091(intragroup allgather)=0.117969
    Universal full duplex allgatherv time=0.050991(message size time)+0.035053(intergroup message transfer)+0.054941(intragroup allgather)=0.140985
    Time used for universal full duplex allgatherv=0.621193, removing extreme=0.361905
  

Questions/Comments:

email: qiao.kang@eecs.northwestern.edu

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