Before we end our study of virtualizing memory, let us take a closer look at how entire virtual memory systems are put together. We’ve seen key elements of such systems, including numerous page-table designs, interactions with the TLB (sometimes, even handled by the OS itself), and strategies for deciding which pages to keep in memory and which to kick out. However, there are many other features that comprise a complete virtual memory system, including numerous features for performance, functionality, and security