Computer Laboratory

Technical reports

Operating system support for quality of service

Eoin Andrew Hyden

June 1994, 102 pages

This technical report is based on a dissertation submitted February 1994 by the author for the degree of Doctor of Philosophy to the University of Cambridge, Wolfson College.

Abstract

The deployment of high speed, multiservice networks within the local area has meant that it has become possible to deliver continuous media data to a general purpose workstation. This, in conjunction with the increasing speed of modern microprocessors, means that it is now possible to write application programs which manipulate continuous media in real-time. Unfortunately, current operating systems do not provide the resource management facilities which are required to ensure the timely execution of such applications.

This dissertation presents a flexible resource management paradigm, based on the notion of Quality of Service, with which it is possible to provide the scheduling support required by continuous media applications. The mechanisms which are required within an operating system to support this paradigm are described, and the design and implementation of a prototypical kernel which implements them is presented.

It is shown that, by augmenting the interface between an application and the operating system, the application can be informed of varying resource availabilities, and can make use of this information to vary the quality of its results. In particular an example decoder application is presented, which makes use of such information and exploits some of the fundamental properties of continuous media data to trade video image quality for the amount of processor time which it receives.

Full text

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BibTeX record

@TechReport{UCAM-CL-TR-340,
  author =	 {Hyden, Eoin Andrew},
  title = 	 {{Operating system support for quality of service}},
  year = 	 1994,
  month = 	 jun,
  url = 	 {http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-340.pdf},
  institution =  {University of Cambridge, Computer Laboratory},
  number = 	 {UCAM-CL-TR-340}
}