Collective benchmark (using models)

The basic usage of this tool and a description how to plot the output file is described in MPIBlib.

Example using a model-based collective:

 $ mpirun -n 16 collective -O Hockney_Scatter_dfs_binomial_min -o model=Hockney,file=model.out -l libcpm_coll.so -m 1024 -M 2049 > collective.out

will benchmark a binomial tree scatter operation with message sizes per process of 1024 and 2048. The binomial tree will be generated through depth-first approach choosing the node with minimum predicted communication by the Hockney model.