Page Replacement

Question

Only "Second chance" is mentioned then how can I know whether it is "FIFO 2nd chance" or "LRU 2nd chance" algorithm ?

Answer 1

The second Chance algorithm is generally a modified version of FIFO. It works just like FIFO, with a slight difference. Instead of swapping out at first go, we look for the status of referenced/use bit. 

• If the reference bit is set - > clear the bit but do not swap out the page.
• If the reference bit isn't set - > swap that page with the new page.
• This swapping happens just like the FIFO method. So Belady's Anomaly can also happen here.