After enabling GarbageCollector in Kubemark, kubemark-scale started failing pretty reliably (all runs failed). Looking into log it seems pretty much related to garbage-collector.

The example failure is here:
http://kubekins.dls.corp.google.com/view/Scalability/job/kubernetes-kubemark-gce-scale/1344/consoleFull

I didn't have time to investigate deeper, but the timing of those failure matches timing of merging:
#30401

@lavalamp @gmarek