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Full-Text Articles in Computer Engineering
Work In Progress: Automating Proportion/Period Scheduling, David Steere, Jonathan Walpole, Calton Pu
Work In Progress: Automating Proportion/Period Scheduling, David Steere, Jonathan Walpole, Calton Pu
Computer Science Faculty Publications and Presentations
The recent effort to define middleware capable of supporting real-time applications creates the opportunity to raise the level of abstraction presented to the programmer. We propose that proportion/period is a better abstraction for specifying resource needs and allocation than priorities. We are currently investigating techniques to address some issues that are restricting use of proportion/period scheduling to research real-time prototypes. In particular, we are investigating techniques to automate the task of selecting proportion and period, and that allow proportion/period to incorporate job importance under overload conditions.
Fine-Grain Period Adaptation In Soft Real-Time Environments, David Steere, Joshua Gruenberg, Dylan Mcnamee, Calton Pu, Jonathan Walpole
Fine-Grain Period Adaptation In Soft Real-Time Environments, David Steere, Joshua Gruenberg, Dylan Mcnamee, Calton Pu, Jonathan Walpole
Computer Science Faculty Publications and Presentations
Reservation-based scheduling delivers a proportion of the CPU to jobs over a period of time. In this paper we argue that automatically determining and assigning this period is both possible and useful in general purpose soft real-time environments such as personal computers and information appliances. The goal of period adaptation is to select the period over which a job is guaranteed to receive its portion of the CPU dynamically and automatically. The choice of period represents a trade-off between the amount of jitter observed by the job and the overall efficiency of the system. Secondary effects of period include quantization …
Qos Scalability For Streamed Media Delivery, Charles Krasic, Jonathan Walpole
Qos Scalability For Streamed Media Delivery, Charles Krasic, Jonathan Walpole
Computer Science Faculty Publications and Presentations
Applications with real-rate progress requirements, such as mediastreaming systems, are difficult to deploy in shared heterogenous environments such as the Internet. On the Internet, mediastreaming systems must be capable of trading off resource requirements against the quality of the media streams they deliver, in order to match wide-ranging dynamic variations in bandwidth between servers and clients. Since quality requirements tend to be user- and task-specific, mechanisms for capturing quality of service requirements and mapping them to appropriate resource-level adaptation policies are required. In this paper, we describe a general approach for automatically mapping user-level quality of service specifications onto resource …
Adaptive Resource Management Via Modular Feedback Control, Ashvin Goel, David Steere, Calton Pu, Jonathan Walpole
Adaptive Resource Management Via Modular Feedback Control, Ashvin Goel, David Steere, Calton Pu, Jonathan Walpole
Computer Science Faculty Publications and Presentations
A key feature of tomorrow’s operating systems and runtime environments is their ability to adapt. Current state of the art uses an ad-hoc approach to building adaptive software, resulting in systems that can be complex, unpredictable and brittle. We advocate a modular and methodical approach for building adaptive system software based on feedback control. The use of feedback allows a system to automatically adapt to dynamically varying environments and loads, and allows the system designer to utilize the substantial body of knowledge in other engineering disciplines for building adaptive systems. We have developed a toolkit called SWiFT that embodies this …