Free page pool

Question

Explain Free page pool?

Answer 1

Free page pool: some systems have a small list of clean pages which are available immediately for replacement.

• During replacement, take the page which has been in the free pool the longest time, then run the replacement algorithm to insert a new page to the free pool.
• Pages in the free pool put their exists bit off, therefore any references to those pages cause a page fault.
• If a page fault takes place for a page in the free pool, eliminate it from the free pool and put it back in service; much faster than reading from disk.
•  Provides an extra chance for recovery if we make a poor page replacement decision.