An Improved Priority Dynamic Quantum Time Round-Robin Scheduling Algorithm

Information Technology

In real-time embedded systems, scheduling policy is considered one of the main factors that affect their performance. It helps to choose which task should be selected first from ready queue to run. Round Robin (RR) scheduling algorithm is widely used and its performance highly depends on a Quantum size Qt, which is a predefined amount of time assigned by CPU to every task to be executed. However, the performance degrades with respect to an average waiting time (AWT), an average Turn­ Around time (ATT) and a number of Context Switches (NCS). This paper presents a new improved dynamic Round Robin scheduling algorithm to reduce the average waiting time, turn­ around time and the number of context switches in order to improve the system overall performance. The queue size distribution and average waiting time for a time-shared system using round-robin (RR) scheduling, with and without overhead, are determined. In this study, the incoming processes are prioritized, and dynamic quantum times are assigned depending on the level of priority. With these parameters, RR versus priority dynamic quantum time round robin scheduling algorithm is analyzed to explore the effect of changing the quantum time of processes and determine the optimum context switches, turnaround time, and waiting time.

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