Basic Strategies

Explore basic free space management strategies used in virtualization to allocate memory efficiently. Understand how best fit, worst fit, first fit, and next fit algorithms work and learn their advantages and performance trade-offs. This lesson helps you grasp foundational allocation policies critical for optimizing memory usage in operating systems.

We'll cover the following...

Best fit
Worst fit
First fit
Next fit
Examples

Now that we have some machinery under our belt, let’s go over some basic strategies for managing free space. These approaches are mostly based on pretty simple policies that you could think up yourself; try it before reading and see if you come up with all of the alternatives (or maybe some new ones!).

The ideal allocator is both fast and minimizes fragmentation. Unfortunately, because the stream of allocation and free requests can be arbitrary (after all, they are determined by the programmer), any particular strategy can do quite badly given the wrong set of inputs. Thus, we will not describe a “best” approach, but rather talk about some basics and discuss their pros and cons.

Basic Strategies

Best fit