Module 4 Introduction

One aspect of operating system design is memory management. Memory costs have decreased dramatically over the years. Many years ago, 640K of RAM was common.  Then 20 meg of RAM  was adequate.  Each of these at the time, cost a great deal of money and was the ideal amount to have. Now, most operating systems cannot practically run on that amount of memory. Consider your PC. Look at your task manager (windows, mac, linux/Unix) and look at the number of processes that you have open on your PC; it is likely more than 50. The operating system needs to determine how to allocate memory to these many processes to present as seamless concurrent operation, even though you likely don't have enough memory to have them all fully loaded in memory at the same time. This requires swapping processes in and out of memory and use of virtual memory.

It is important to understand memory management to be able to effectively select and integrate Operating System solutions.

In this module, we'll examine memory management.