After this documentation was released in July 2003, I was approached by Prentice Hall and asked to write a book on the Linux VM under the Bruce Peren's Open Book Series.

The book is available and called simply "Understanding The Linux Virtual Memory Manager". There is a lot of additional material in the book that is not available here, including details on later 2.4 kernels, introductions to 2.6, a whole new chapter on the shared memory filesystem, coverage of TLB management, a lot more code commentary, countless other additions and clarifications and a CD with lots of cool stuff on it. This material (although now dated and lacking in comparison to the book) will remain available although I obviously encourge you to buy the book from your favourite book store :-) . As the book is under the Bruce Perens Open Book Series, it will be available 90 days after appearing on the book shelves which means it is not available right now. When it is available, it will be downloadable from http://www.phptr.com/perens so check there for more information.

To be fully clear, this webpage is not the actual book.

12.7 Swapping In Pages

The principal function used when reading in pages is read_swap_cache_async() which is called during page faulting for instance. This function is called as it first searches the swap cache with find_get_page() and returns it if it does. If it does not already exist, a new page is allocated with alloc_page(), it is added to the swap cache with add_to_swap_cache() and finally the IO is started with rw_swap_page() with flags to start the read operation which is covered in detail later.