The Case for Using Middleware to Manage Diverse Soft Real-Time Schedulers

John Regehr and Jay Lepreau
{regehr,lepreau}@cs.utah.edu

University of Utah, School of Computing
50 South Central Campus Drive, Room 3190
Salt Lake City, Utah 84112-9205
http://www.cs.utah.edu/flux/

Abstract

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.

Appeared in Proceedings of the International Workshop on Multimedia Middleware (M3W '01), pages 23-27, Ottawa, Canada, October 2001.

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Citation information:

@InProceedings{RegehrM3W01,
  author =       "John Regehr and Jay Lepreau",
  title =        "The Case for Using Middleware to Manage Diverse Soft
                 Real-Time Schedulers",
  booktitle =    "Proc.\ of the International Workshop on Multimedia
                 Middleware (M3W '01)",
  pages =        "23--27",
  address =      "Ottawa, Canada",
  month =        oct,
  year =         "2001",
}