• The replacement policy determines which virtual page must be removed from memory to make room for a new page. Of the replacement policies considered in Chapter 3, the VM Manager uses a local FIFO replacement policy and keeps track of the pages currently in memory for each process—the process’s working set. The FIFO algorithm is local to each process, so that when a page fault occurs, only page frames owned by a process can be freed. When it’s created, each process is assigned a minimum working-set size, which is the number of pages the process is guaranteed
to have in memory while it’s executing. If memory isn’t very full, the VM Manager allows the process to have the pages it needs up to its working set maximum. If the process requires even more pages, the VM Manager removes one of the process’s pages for each new page fault the process generates.