Workload Examples

Compare how different policies behave with different workloads of a system in this lesson.

Let’s look at a few more examples in order to better understand how some of these policies behave. Here, we’ll examine more complex workloads instead of small traces. However, even these workloads are greatly simplified; a better study would include application traces.

Example: workload without locality

Our first workload has no locality, which means that each reference is to a random page within the set of accessed pages. In this simple example, the workload accesses 100 unique pages over time, choosing the next page to refer to at random; overall, 10,000 pages are accessed. In the experiment, we vary the cache size from very small (1 page) to enough to hold all the unique pages (100 pages), in order to see how each policy behaves over the range of cache sizes.

The figure below plots the results of the experiment for optimal, LRU, Random, and FIFO. The y-axis of the figure shows the hit rate that each policy achieves; the x-axis varies the cache size as described above.

Get hands-on with 1200+ tech skills courses.