FIFO
FIFO is an obvious algorithm and simple to implement.
Basic idea, maintain a list or queue of pages in the order in which they were paged into memory.
On replacement, remove the one brought in the longest time ago.
Why might it work?
- Maybe the one brought in the longest ago is one we’re not using now.
Why it might not work?
- Maybe it’s not.
- We have no real information to tell us if it’s being used or not.
FIFO suffers from “Belady’s anomaly”
- the fault rate might actually increase when the algorithm is given more memory -- a bad property.