Page replacement algorithm
ALGORITHM IN AN OS THAT DECIDES WHICH MEMORY PAGES TO PAGE OUT (SWAP OUT, WRITE TO DISK) WHEN A REQUESTED PAGE IS NOT IN MEMORY (PAGE FAULT) AND A FREE PAGE CANNOT BE USED TO SATISFY THE ALLOCATION (BECAUSE THERE ARE TOO FEW OR NONE)
Page replacement algorithms; Not recently used; Local replacement algorithm; Second chance replacement strategy; Second-chance replacement strategy; Second-chance algorithm; Second chance algorithm; Clock with Adaptive Replacement; Clock with adaptive replacement; Page replacement
In a computer operating system that uses paging for virtual memory management, page replacement algorithms decide which memory pages to page out, sometimes called swap out, or write to disk, when a page of memory needs to be allocated. Page replacement happens when a requested page is not in memory (page fault) and a free page cannot be used to satisfy the allocation, either because there are none, or because the number of free pages is lower than some threshold.