Demand paging

[jason s]

Demand paging is an application of virtual memory. In a system where Demand paging is used, the operating system copies a disk page into physical memory only if an attempt is made to access it. It works in the process, execution begins with none of its pages in the physical memory and many page faults will occur until most of a process's working set of pages is located in physical memory. It's one of the best example of Lazy loading techniques.