Statistical processor service guarantee for continuous media applications

• Main Author: Laoh, Peggy K.
• Format: text
• Language: English
• Published: Animo Repository 1997
• Subjects: Statistical services; Real-time programming; Computer simulation; Computer systems; Computer design; Information technology; Communication; Computer Sciences
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/1736; https://animorepository.dlsu.edu.ph/cgi/viewcontent.cgi?article=8574&context=etd_masteral
• Institution: De La Salle University

Continuous media tasks have a highly unpredictable processor time requirement. But this type of application has a real-time requirement that requires the processor to provide service guarantee. Several attempts have been made to design a processor manager that satisfies the above requirement. However, none have attempts to provide statistical guarantee to processor service. Statistical processor guarantee allocates processor among several tasks based on distribution characteristic of these tasks as opposed to the existing processor manager that allocates processor based on average case or worst case. It is the objective of this research to design a processor manager that provides statistical service guarantee to continuous media tasks. The processor manager uses a processor delay model when reserving and allocating processor cycle. The processor delay model made a prediction of the computation time of a task based on that task's past computation time. It utilizes the Central Limit Theorem when making normal approximation and window estimator when estimating the computation time of a task. The processor manager also performs admission control test to decide whether a task can be accepted to the system based on available processor capacity and current processing time characteristics of admitted tasks. The admitted tasks are scheduled using Earliest Deadline First (EDF) scheduling mechanism which has been proven to be optimal in scheduling continuous media tasks. The presence of adaptation manager further increases the effectiveness of the processor manager to provide a service guarantee according to the requirements and nature of continuous media applications. The adaptation manager performs feedback to applications when processor requirements change or the demand for processor times exceed available capacity. The characteristics and properties of the processor manager are further investigated by using performance results from a trace-driven simulation. The result of this simulation shows that the processor manager satisfies the proposed objective this research.