Designing and Implementing of Earliest Deadline First Scheduling Algorithm on Standard Linux

Abstract

This thesis focuses on the problem of utilizing a desktop operating system to provide support for concurrent Real-Time (RT) processes. The operating system discussed is Linux. An Introduction into the nature of real time is given as well as justifications for using a desktop operating system (OS) as a Real-Time OS (RTOS). RT processes are characterized and the EDF scheduling algorithm is discussed. The characteristics that make up a RTOS are given and their relationship to Linux is discussed. Many real-time operating systems like RT-Linux schedule tasks according to their priorities. However, the theoretical results expose that EDF scheduling brings better performance. It gave me impetus to implement EDF scheduler in Linux. In fact, EDF ready queue is more difficult to implement than ready queue with fixed priority levels since ready tasks have to be order by ascending absolute deadline that change for each instance of task and can take the value from wide range. This project proposed and implemented the EDF scheduling algorithm for Linux O.S. This structure has the linear space complexity. Time complexity of operations handling in the worst case. This document describes implementation of Earliest Dead Line First scheduling solution.