CPU Scheduling Review

These flashcards cover essential vocabulary and concepts related to CPU scheduling and process states.

Scheduler

A component that maintains the status of each process and decides the order of execution.

Process States

The various states a process can be in during its life cycle, including New, Ready, Running, Blocked, and Terminated.

New State

The state where a process has been created but is not yet in memory.

Ready State

The state where a process is in memory and waiting to be assigned a CPU.

Running State

The state where a process is currently being executed by the CPU.

Blocked State

The state where a process is waiting for some event to occur, such as a completion of an I/O operation.

Terminated State

The state where a process has completed its execution.

Context Switch

The process of saving the execution context of a currently running process and loading the context for the next process to execute.

Dispatch Latency

The amount of time it takes for the OS to stop one process and start another.

CPU Scheduling Algorithms

Methods that determine the order in which processes are executed on the CPU.

First Come First Served (FCFS)

A non-preemptive scheduling algorithm where processes are executed in the order they arrive.

Shortest Job First (SJF)

A scheduling algorithm that executes processes based on the length of their CPU burst, selecting the shortest first.

Priority Scheduling

A scheduling algorithm that executes processes based on priority levels, either numerical or defined by the system.

Round Robin (RR)

A preemptive scheduling algorithm that allows each process to run for a fixed time quantum before moving to the next.

Multi-Level Queue

A scheduling method that uses multiple queues for process management, with each queue having its own scheduling algorithm.

Multi-Level Feedback Queue

A scheduling method that allows processes to move between multiple queues, promoting and demoting their priority.

Starvation

A condition where a process is perpetually denied access to resources due to other processes continuously taking precedence.

Aging

A technique used in priority scheduling to prevent starvation, where the priority of a waiting process is gradually increased.

Time Quantum

The fixed amount of time a process is allowed to run in a time-sharing scheduling algorithm like Round Robin.