Operating Systems

Start Lecture #15

Chapter 3 Memory Management

Also called storage management or space management.

The memory manager must deal with the storage hierarchy present in modern machines.

We will see in the next few weeks that there are three independent decision:

  1. Should we have segmentation.
  2. Should we have paging.
  3. Should we employ fetch on demand.

Memory management implements address translation.

Homework: What is the difference between a physical address and a virtual address?

When is address translation performed?

  1. At compile time
  2. At link-edit time (the linker lab)
  3. At load time
  4. At execution time


  1. Dynamic Loading
  2. Dynamic Linking.
Note: I will place ** before each memory management scheme.

3.1 No Memory Management

The entire process remains in memory from start to finish and does not move.

The sum of the memory requirements of all jobs in the system cannot exceed the size of physical memory.


The good old days when everything was easy.