Hello all, I am a kernel newbie. While reading about the page cache from "Understanding the Linux Kernel",3rd Edition, I came to know that... Page cache is used to hold pages that contain the data read/written from disk. Whenever a file is read from disk, the data is first copied in page in Page Cache and then to userspace buffer. Similarly,while writing the data is first written to page in page cache and then to the disk(deferred write). Buffer cache is now implemented through Page Cache(there's no separate Buffer Cache now)...those pages that are used as buffer cache in the Page cache are called as "buffer pages" My question is :
What type of data is held by "normal pages" in Page Cache and what
data is held by "buffer caches"? As any read/write from/to the disk will be in the form of blocks and in that case all pages will be divided in buffers maintained by "Buffer Heads"... "normal pages" in page cache contain the data read/written from/to the disk and so does the "buffer pages".. so whats the difference between the two?
What type of disk I/O require "buffer pages" and what type of disk
I/O can be done without "buffer pages" ? I am totally confused..kindly help!! -Adheer -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
