> CFS quotas only become active under contention
That's not true at all. Take a look at `cpu.cfs_quota_us` in https://kernel.googlesource.com/pub/scm/linux/kernel/git/glo...
It's a hard time limit. It doesn't care about contention at all.
`cpu.shares` is relative, for choosing which process gets scheduled, and how often, but the CFS quota is a hard limit on runtime.