Betweenness Centrality (BC) is a graph analytics application that is part of the Pannotia benchmark suite. It is used to calculate betweenness centrality scores for all the vertices in a graph. The provided version is for use with the gpu-compute model of gem5. Thus, it has been ported from the prior CUDA and OpenCL variants to HIP, and validated on a Vega-class AMD GPU.

Compiling BC, compiling the GCN3_X86/Vega_X86 versions of gem5, and running BC on gem5 is dependent on the gcn-gpu docker image, util/dockerfiles/gcn-gpu/Dockerfile on the gem5 stable branch.

Compilation and Running

To compile BC:

cd src/gpu/pannotia/bc
docker run --rm -v ${PWD}:${PWD} -w ${PWD} -u $UID:$GID make gem5-fusion

If you use the Makefile.default file instead, the Makefile will generate code designed to run on the real GPU instead. Moreover, note that Makefile.gem5-fusion requires you to set the GEM5_ROOT variable (either on the command line or by modifying the Makefile), because the Pannotia applications have been updated to use m5ops. By default, the Makefile builds for gfx801 and gfx803, and is placed in the src/gpu/pannotia/bc/bin folder.

Compiling GCN3_X86/gem5.opt

BC is a GPU application, which requires that gem5 is built with the GCN3_X86 (or Vega_X86, although this has been less heavily tested) architecture. The test is run with the GCN3_X86 gem5 variant, compiled using the gcn-gpu docker image:

git clone
cd gem5
docker run -u $UID:$GID --volume $(pwd):$(pwd) -w $(pwd) scons build/GCN3_X86/gem5.opt -j <num cores>

Running BC on GCN3_X86/gem5.opt

Assuming gem5 and gem5-resources are in your working directory

docker run --rm -v ${PWD}:${PWD} -w ${PWD} -u $UID:$GID gem5/build/GCN3_X86/gem5.opt gem5/configs/example/ -n3 --mem-size=8GB --benchmark-root=gem5-resources/src/gpu/pannotia/bc/bin -c bc.gem5 --options=""

Note that the datasets from the original Pannotia suite have been uploaded to: We recommend you start with the input (, as this is the smallest input designed to run with BC.

Pre-built binary

A pre-built binary will be added soon.