This is the simplest page replacement algorithm. In this algorithm, the operating system keeps track of all
pages in the memory in a queue, the oldest page is in the front of the queue. When a page needs to be
replaced page in the front of the queue is selected for removal.
Example-1Consider page reference string 1, 3, 0, 3, 5, 6 with 3 page frames.Find number of page
faults.
Initially all slots are empty, so when 1, 3, 0 came they are allocated to the empty slots —> 3 Page Faults.
when 3 comes, it is already in memory so —> 0 Page Faults.
Then 5 comes, it is not available in memory so it replaces the oldest page slot i.e 1. —>1 Page Fault.
6 comes, it is also not available in memory so it replaces the oldest page slot i.e 3 —>1 Page Fault.
Finally when 3 come it is not avilable so it replaces 0 1 page fault
