The fact that this stat disappeared from cgroups v2 is consistent with the frustrating theme that cgroup v2 did not understand the lessons of cgroup v1, and tha

The fact that this stat disappeared from cgroups v2 is consistent with the frustrating theme that cgroup v2 did not understand the lessons of cgroup v1, and that the maintainers/gatekeepers of these subsystems do not necessarily have the experience to perceive the tradeoffs of disabling or removing these things. In a multitenant environment with hundreds of tasks contending for CPUs on a single box, the delay stat is one of the most useful, or at least it was before it disappeared in cgroups v2.