AN EFFICIENT THRESHOLD ROUND-ROBIN SCHEME FOR CPU SCHEDULING (ETRR)

Round Robin is a common CPU scheduling algorithm in multi-programmed operating systems. Its performance depends entirely on the value of time quantum. In this paper, an efficient ETRR scheme is proposed. This technique proposed the partitioning of the ready queue into three sub-queues: highest, medium, and lowest priority. It was found out that the assignment of the time quantum value (TQ) to one of those sub-queues is depending on a threshold value. Every sub-queue uses RR scheduling with separated dynamic time quantum TQi for i=1, 2, and 3. All processes in TQ1 must be executed first. Then are in TQ2 and TQ3, respectively. The experimental results show that the ETRR is outperforming other approaches such as SRBRR, ISRBRR, and MFQ.