Библиотека сайта rus-linux.net
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.
Next: 13. Out Of Memory Up: 12. Swap Management Previous: 12.8 Swapping Out Pages Contents Index
12.9 Reading/Writing the Swap Area
The top-level function for reading and writing to the swap area is
rw_swap_page(). This function ensures that all operations are
performed through the swap cache to prevent lost updates.
rw_swap_page_base() is the core function which performs the real
work.
It begins by checking if the operation is a read. If it is, it clears
the uptodate flag with ClearPageUptodate(). This flag will
be set again if the page is successfully read from disk. It then calls
get_swaphandle_info() to acquire the device for the swap partition
of the inode for the file. These are needed before block IO operations may
be performed.
If the swap area is a file, bmap() is used to fill a local
array with a list of all blocks in the filesystem which contain the page
being operated on. Remember that filesystems may have their own method of
storing files and disk and it is not as simple as the swap partition where
information may be written directly to disk.
Once that is complete, a normal block IO operation takes place with
brw_page(). The function of block IO is beyond the scope of
this document.
Next: 13. Out Of Memory Up: 12. Swap Management Previous: 12.8 Swapping Out Pages Contents Index Mel 2004-02-15