informIT: Page Table Management Oct 7, 2004, 08 :30 UTC (0 Talkback[s]) (2770 reads) (Other stories by Mel Gorman)
"Linux layers the machine independent/dependent layer in an unusual manner in comparison to other operating systems [CP99]. Other operating systems have objects that manage the underlying physical pages, such as the pmap object in BSD. Linux instead maintains the concept of a three-level page table in the architecture-independent code even if the underlying architecture does not support it. Although this is conceptually easy to understand, it also means that the distinction between different types of pages is very blurry, and page types are identified by their flags or what lists they exist on rather than the objects they belong to..."