Scheduling forms an important aspect of operating systems because it has a direct impact on system performance. Most existing general-purpose schedulers use a priority-based scheme to schedule processes. Such priority-based mechanisms cannot guarantee proportional fairness for every process. Proportional share schedulers maintain fairness among tasks based on given weight values. In both of these scheduler types, the scheduling decision is done per-process. However, system usage policies are typically set on a per-consumer basis, where a consumer represents a group of related processes that may belong to the same application or user.

The COPS framework uses the idea of consumer sets to group processes. Its design guarantees system usage per consumer, based on relative weights. We have added a share management layer on top of a proportional share scheduler to ease the administrative job of share assignment for these consumer sets. We have evaluated our system in real world scenarios and show that the CPU usage for consumer sets with CPU-bound processes complies with the administrator-defined policy goals.