Unsupported ruby prof features in ruby 2.2

I am currently running ruby 2.2.2 and rails 4.2 and when I include 'rails-perftest' and 'ruby-prof' in the gemfile I get the following output.

wall_time: 7 ms
memory: unsupported
objects: unsupported
gc_runs: 0
gc_time: 0 ms

Is there any way to see the memory and objects outputs or is this completely impossible with ruby 2.2.2?