One vital use of address_space object is by filesystem to manage page-cache of a file: - cache recently accessed data in page-cache - Read-ahead (prefectiching) of data sequentially read data in page-cache - support memory mapped I/O through page-cache. Look at address_space_operations vector how it achieve it through readpage, readpages, writepage and writepages methods to populate and flush page-cache of an inode. Thanks, Rajat On Mon, Feb 14, 2011 at 4:29 PM, piyush moghe <pmkernel@xxxxxxxxx> wrote: > While going through Page Cache explanation in "Professional Linux Kernel" > book I came across one term called "address space" ( not related to virtual > or physical address space ) > I did not get what is the meaning of this address space, following is > verbatim description: > "To manage the various target objects that can be processed and cached in > whole pages, the kernel uses an abstraction of > the "address space" that associates the pages in memory with a specific > block device (or any other system unit or part of a > system unit). > This type of address space must not be confused with the virtual and > physical address spaces provided by the > system or processor. It is a separate abstraction of the Linux kernel that > unfortunately bears the same name. > Initially, we are interested in only one aspect. Each address space has a > "host" from which it obtains its data. In most > cases, these are inodes that represent just one file.[2] Because all > existing inodes are linked with their superblock (as > discussed in Chapter 8), all the kernel need do is scan a list of all > superblocks and follow their associated inodes to obtain > a list of cached pages" > > Can anyone please explain what is the use of this and what this is all > about? > Regards, > Piyush > > > > _______________________________________________ > Kernelnewbies mailing list > Kernelnewbies@xxxxxxxxxxxxxxxxx > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > > _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
