[Linux Kernel] What does pdflush do?

Linux usually writes data out of the page cache using a process called pdflush.

At any moment, between 2 and 8 pdflush threads are running on the system. You can monitor how many are active by looking at /proc/sys/vm/nr_pdflush_threads.

As you write out data ultimately intended for disk, Linux caches this information in an area of memory called the page cache. You can find out basic info about the page cache using tools like free, vmstat or top

Old version of Linux (before 2.6) uses kupdated or bdflush instead.

Original Link: http://itmission.org/wiki/?n=Main.What-is-pdflush