the case for using middleware to manage diverse soft real-time schedulers
Although a number of general-purpose operating systems have been extended with soft real-time schedulers and have the potential to support coexisting, independently developed real-time applications, this potential is currently largely unexploited by common applications. This is because the provided scheduling functionality is low-level and depends on parameters that are difficult to estimate, and because different semantics are provided by different schedulers. The cost/benefit ratio of real-time support in general-purpose operating systems is too high for most users and application developers to tolerate.The contribution of this paper is the design of the CPU Resource Manager (CRM): a middleware application that manages processor allocation in a QoS-enabled general-purpose operating system by (1) providing a level of indirection between applications and the scheduling subsystem, (2) automatically calculating scheduling parameters when applicable, and (3) providing an environment supporting the execution of user-specified rules about the allocation of processor time. The focus of this work is not to increase the benefit provided by real-time schedulers, but rather to decrease the cost of using them.
middleware soft real-time resource management open systems scheduler composition multimedia scheduler parameter estimation