Tested this and it works as expected. My test code worked as follows:

control, err := cgroups.Load(cgroups.SingleSubsystem(cgroups.Systemd, cgroups.Pids), cgroups.Slice("system.slice", "docker.service"))

Can you sign your commit with the DCO? git commit -s --amend?

https://github.com/containerd/containerd/blob/master/CONTRIBUTING.md#sign-your-work

Thanks for working on this!

Codecov Report

Merging #52 into master will not change coverage.
The diff coverage is 0%.

@@           Coverage Diff           @@
##           master      #52   +/-   ##
=======================================
  Coverage   13.32%   13.32%           
=======================================
  Files          23       23           
  Lines        4518     4518           
=======================================
  Hits          602      602           
  Misses       3800     3800           
  Partials      116      116

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 2e2922e...2596f33. Read the comment docs.

@crosbymichael Think I have done this - although I ended up with 3 commits for 1 tiny change :(

@Sykomaniac if you amend and force push it should be one. you can git rebase -i HEAD~3 and squash

@crosbymichael Force push done - now only one commit

LGTM