Advances In CPU Scheduling Algorithms in Operating Systems

CPU scheduling algorithms significantly influence Operating System (OS) performance. Many studies have proposed optimized scheduling algorithms. This paper outlines the main characteristics of common scheduling algorithms, including First Come First Served (FCFS), Shortest Job First (SJF), Round Robin (RR), Priority Scheduling, and Highest Response Ratio Next (HRRN). It reviews comparative performance research on these algorithms and mentions their optimizations to summarize the progress in this field. This paper also analyses two specific operating systems - Time-Sharing Systems and Embedded Systems, and introduces scheduling algorithms applicable to these two systems and their typical applications. The review finds that SJF & SPTF perform better than FCFS and RR in terms of waiting time, while HRRN also significantly outperforms RR. The optimization of the scheduling algorithm mainly focuses on RR, by clustering techniques and dynamically resizing the quantum time. For time-sharing systems, RR is the most common strategy, while the Linux kernel adopts the Completely Fair Scheduler (CFS). For embedded systems, the real-time scheduling algorithms, Earliest Deadline First(EDF) and Least Slack Time(LST), are applicable to soft real-time systems.