Page Buffering Algorithm
As an add-on to any previous algorithm.
A pool of free frames is maintained.
When a page fault occurs, the desired page is read into a free frame from the pool. The victim frame is later swapped out if necessary and put into the free frames pool.
Advantage / disadvantage ?
Plus - Process is put back to ready queue faster.
Minus - less pages are in use overall.
VAX/VMS version - basic FIFO replacement with a free frame pool. A victim is put into the pool but the original virtual address is kept. When a page fault occurs, we first look in the pool. If we find the page there - no need for disk operation.