Memory Management

Memory management is how our OS handles virtual and physical memory (RAM). Please make sure to understand what a frame (fixed length block of physical memory) and a page are as these are often used when talking about memory.

In Module 1 we learned about creating a swap partition. Though, the reason for this was never really touched upon. We created this special partition as at times we do not have enough RAM to hold the requirements of all active processes. So, to handle this we use the swap partition and a process that is currently not needed or has not run in a while is copied to disk in order to free up RAM space. Once the process is scheduled to run it will be swapped back to RAM in order to run. This process continues behind the scenes in the OS and the end users never really notice this taking place. Also, computer systems these days have higher amounts of RAM, so we might not have to swap out as much due to this increased space.

Besides swapping there are other memory management techniques as well. Another one is called Contiguous Memory Allocation. This is a very simple method as memory is divided into fixed sized partitions and each partition contains a single process. When a partition is free a process is selected and copied into the empty partition location.

Memory management is a very complex topic and entire chapters of books on OS theory have been dedicated to this one topic. This section was just a short introduction into this complex topic.