Page Frame Number Database
In several previous sections, we’ve concentrated on the virtual view of a Windows process—page tables, PTEs, and VADs. In the remainder of this chapter, we’ll explain how Windows manages physical memory, starting with how Windows keeps track of physical memory. Whereas working sets describe the resident pages owned by a process or the system, the page frame number (PFN) database describes the state of each page in physical memory. The page states are listed in Table 10-16.
Table 10-16. Page States
Active (also called Valid)
The page is part of a working set (either a process working set, a session working set, or a system working set), or it’s not in any working set (for example, nonpaged kernel page) ...