Operating Systems: Concurrent and Distributed Software Design

5.7. Operating system data structures

As main memories have become larger, the criteria for designing OS memory management algorithms have changed. An important factor on modern processors with vast 64-bit virtual address spaces is that the size of the data structures needed to support memory management should depend on the amount of that address space that is in use rather than on its total size. For example, a simple page table holding a mapping for each virtual page would be impracticable at such a size.

Realistic algorithms exploit the fact that a process's pages are allocated in clusters which are widely dispersed in the virtual address space according to software conventions. The UNIX and Windows case studies in Part IV will show how so-called ...