[$] Scheduler benchmarking with MMTests

The MMTests benchmarkingsystem is normally associated with its initial use case: testingmemory-management changes. Increasingly, though, MMTests is not limited tomemory management testing; at the 2020 Power Management and Schedulingin the Linux Kernel summit (OSPM), Dario Faggioli talked about how heis using it to evaluate changes to the CPU scheduler, along with adiscussion of the changes he had to make to get useful results for systemshosting virtualized guests.