Process Scheduling Algorithms Overview: Process scheduling algorithms determine the sequence in which processes execute on a multi-user system. These al...
Process Scheduling Algorithms
Overview:
Process scheduling algorithms determine the sequence in which processes execute on a multi-user system. These algorithms are responsible for assigning resources to processes, managing their execution, and ensuring that all processes execute correctly and timely.
Types of Process Scheduling Algorithms:
First-Come, First-Served (FCFS):
Processes are executed in the order they arrive.
It is simple to implement but can lead to starvation, where processes are starved of resources.
Shortest Job First (SJF):
Processes with the shortest execution time are executed first.
It is fair but can result in inefficient scheduling for processes with longer execution times.
Priority-Based:
Processes are assigned priorities, and those with higher priorities are executed first.
It allows for prioritizing specific processes but can lead to starvation of lower-priority processes.
Round Robin:
Processes are assigned a specific execution time called a quantum.
It ensures fairness and prevents starvation but can be inefficient for long processes.
Multi-Level Feedback Queue (MLFQ):
It consists of multiple levels, each with its own feedback queue.
Processes move between queues based on their priorities and resource availability.
Characteristics of Good Process Scheduling Algorithms:
Fairness: All processes are given equal opportunities to execute.
Responsiveness: The algorithm should be able to quickly schedule and execute processes.
Resource efficiency: It should assign resources in a way that minimizes idle time.
Scalability: It should be able to handle a large number of processes efficiently.
Examples:
In a multi-user system with multiple processes running, the FCFS algorithm would assign them execution order 1, 2, 3, ... .
In a system with priority-based scheduling, process 1 might have a higher priority than process 2, while process 3 might have a lower priority.
In an MLFQ system, processes would move through the queues based on their priorities and resource availability