Scheduling Mechanisms: Context Switching and Policies

This lecture covers the essential mechanisms and policies involved in operating system scheduling. It begins with an overview of process abstraction and the APIs used to manage processes, emphasizing the importance of scheduling in operating systems. The instructor explains the two primary mechanisms: context switching and preemption. Context switching is detailed as the process of saving the state of a currently running process and loading the state of another process, allowing for multitasking. The lecture also discusses the process state transitions, illustrating how processes move between running, ready, and blocked states. Preemption is introduced as a critical mechanism that ensures the operating system retains control over hardware resources, preventing any single process from monopolizing the CPU. The lecture concludes with a discussion of various scheduling policies, including first-in-first-out, shortest job first, and round robin, highlighting how these policies determine which process to run next based on specific metrics. Overall, the lecture provides a comprehensive understanding of scheduling mechanisms in computer systems.