OpenMP-based parallel program for counting the number of triangles in a sparse graph
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OpenMP-based parallel program for counting the number of triangles in a sparse graph.

Build requirements

Assuming that the above are available, two commands should suffice to build the software:

make config 

Configuring the build

It is primarily configured by passing options to make config. For example:

make config cc=icc

would configure it to be built using icc.

Configuration options are:

cc=[compiler]     - The C compiler to use [default: gcc]
prefix=[PATH]     - Set the installation prefix [default: ~/local]
gklib_path=[PATH] - Where GKlib was installed [default: ~/local]
openmp=not-set    - To build a serial version

Building and installing

To build and install, run the following

make install

Other make commands

make uninstall 
     Removes all files installed by 'make install'.

make clean 
     Removes all object files but retains the configuration options.

make distclean 
     Performs clean and completely removes the build directory.

Runing the program

By default, the binary, called gktc, will be installed in ~/local/bin. For usage information just type

gktc -help

Usage: gktc [options] infile

     Specifies the format of the input file.
     Possible values are:
        metis   Metis format [default]
        tsv     tsv format (i, j, v)

     Specifies the number of threads to use.
     The default value is set to the value returned by omp_get_max_threads().

     Prints this message.

The program supports two formats for its input files:

  • The one used by the Metis graph partitioning program.
  • The tsv format used by the graphs in the GraphChallenge 2017 competition. Note that the graph has to be undirected and it needs to include both pairs of edges (i.e., (u,v) and (v,u)).

Here is the output of a sample run:

gktc -nthreads=4 test/p2p-Gnutella31.metis
Reading graph test/p2p-Gnutella31.metis...

  infile: test/p2p-Gnutella31.metis
  #nvtxs: 62586
 #nedges: 295784
nthreads: 4

& compatible maxhmsize: 255, startv: 23

  #triangles:         2024; #probes:       209251; rate:     248.56 MP/sec

     preprocessing:     0.002s
 triangle counting:     0.001s
    total (/x i/o):     0.003s


The following shows a sample of gktc's performance on Intel's Knights Landing processor:

     #p: # of threads (this KNL has 68 cores)
  total: total time excluding I/O
    ppt: pre-processing time
    tct: triangle counting time
speedup: relative to p=1

rmat scale25 
#p     total     ppt       tct   speedup 
1      767.4s  141.9s    625.5s   
5      154.4s   29.1s    125.2s     5.0x 
10      77.2s   14.5s     62.6s     9.9x
20      38.6s    7.3s     31.2s    19.9x
40      19.6s    3.7s     16.1s    39.2x
68      12.2s    2.2s      9.9s    62.9x
136      9.3s    1.7s      7.6s    82.5x
272     10.1s    1.5s      8.6s    76.0x

#p     total     ppt       tct   speedup    
1     1422.6s  307.7s   1114.9s  
5      285.7s   62.3s    223.2s     5.0x 
10     143.4s   31.2s    112.1s     9.9x 
20      71.4s   15.6s     55.8s    19.9x 
40      37.1s    7.9s     29.1s    38.4x 
68      23.1s    4.8s     18.3s    61.6x 
136     17.1s    3.4s     13.6s    83.2x 
272     19.3s    3.2s     16.0s    73.7x 

#p     total     ppt       tct   speedup  
1     1618.5s  421.3s   1196.7s   
5      316.8s   84.8s    231.5s     5.1x  
10     159.0s   42.5s    116.1s    10.2x 
20      79.5s   21.3s     57.8s    20.4x
40      40.6s   10.7s     29.4s    39.9x 
68      25.5s    6.5s     18.4s    63.5x 
136     16.9s    4.5s     11.7s    95.8x 
272     13.5s    3.6s      8.9s   119.9x 


The parallel algorithm implemented is based on the one described in

"Exploring Optimizations on Shared-memory Platforms for Parallel Triangle Counting Algorithms." Ancy Sarah Tom, Narayanan Sundaram, Nesreen K. Ahmed, Shaden Smith, Stijn Eyerman, Midhunchandra Kodiyath, Ibrahim Hur, Fabrizio Petrini, and George Karypis. IEEE High Performance Extreme Computing Conference (HPEC), 2017

This was one of the finalists for the GraphChallenge 2017 competition.