Editing Page replacement algorithm (section)

== Local vs. global replacement ==
Replacement algorithms can be ''local'' or ''global.''

When a process incurs a page fault, a local page replacement algorithm selects for replacement some page that belongs to that same process (or a group of processes sharing a [[Memory management (operating systems)#Partitioned allocation|memory partition]]).
A global replacement algorithm is free to select any page in memory.

Local page replacement assumes some form of memory partitioning that determines how many pages are to be assigned to a given process or a group of processes. Most popular forms of partitioning are ''fixed partitioning'' and ''balanced set'' algorithms based on the [[working set]] model. The advantage of local page replacement is its scalability: each process can handle its page faults independently, leading to more consistent performance for that process. However global page replacement is more efficient on an overall system basis.<ref>{{cite web|last1=Bell|first1=John|title=Operating Systems Course Notes: Virtual Memory |url=http://www2.cs.uic.edu/~jbell/CourseNotes/OperatingSystems/9_VirtualMemory.html|website=University of Illinois at Chicago College of Engineering|access-date=21 July 2017|archive-url=https://web.archive.org/web/20180923235717/http://www2.cs.uic.edu/~jbell/CourseNotes/OperatingSystems/9_VirtualMemory.html|archive-date=23 September 2018|url-status=live}}</ref>