Will It Scale takes a testcase and runs it from 1 through to n parallel copies
to see if the testcase will scale. It builds both a process and threads based
test in order to see any differences between the two.

We rely on hwloc for a platform independent way of laying out tasks on cores.
It can be found at www.open-mpi.org/projects/hwloc/.

Care is taken to try and reduce run to run variability. By using hwloc we ensure
each task is on its own core and won't get bounced around by the scheduler. The
wrapper script (runtest.py) turns off address space randomisation which can
cause huge differences in pagetable related benchmarks (one run may fit within
one pte page, the next may span two). There is a warmup period before which an
average is taken. The averaging period can be changed with the -s option, which
by default is 5 seconds.