Abstract
A hierarchical scheduling mechanism has been implemented in RED-Linux to integrate different scheduling paradigms together. In this paper, we extend the concept of group so that the execution budget for jobs in RED-Linux can be managed in a hierarchical way. A budget group contains a set of jobs that share the available budget for the group. The jobs in a budget group could be a normal job or another budget group job, which contains its own group of jobs. Every job has its system budget. But if it belongs to a budget group, the job's budget is also constrained by its group's budget. We discuss how the budget group mechanism is implemented in RED-Linux. We also show how to use the mechanism to implement several schedulers.