Operating Systems · Chapter 8

Memory Allocation Simulator

Compare contiguous memory allocation strategies. Allocate processes, free them, and observe how holes and external fragmentation evolve.

Algorithm Process ID Process size Scenario

Memory Map

Total free memory–

Largest free block–

External fragmentation–

Allocated processes–

Allocated Processes

Process	Size	Start	End	Action

Event Log

Algorithm Guide

First Fit: choose the first hole large enough.

Best Fit: choose the smallest hole that can satisfy the request.

Worst Fit: choose the largest available hole.

Next Fit: like First Fit, but continue searching from the previous allocation position.

External fragmentation is approximated here as total free memory minus the largest free block. A high value means free space is split across many smaller holes.