Today tells Demand Paging. The previous UNIX operating system is swapping on PDP-11, not Demand Paging, because Demang Paging requires hardware support (Restartable Instructions) and operating system support. The current operating system, such as the BSD UNIX is Demand Paging, the principle is part of the program access, so the page that is often accessed constitutes a collection, called a work set, (Working Set). DEMAND PAGING includes 1) Page Table Entries, 2) Disk Block Descriptors, 3) Page Frame Data Table, 4) SWAP-Use TABLE. Page Frame Data Table is a global data structure assigned when operating system initialization, which uses Hash List and Free List, similar to Buffer Cache in the file system. The process of the process contains Per Process Region Talbe, where each entry corresponds to a region (such as BSS Region, Data Region, Stack Region, Shared Region, etc.), each entry contains this REGON in the entire virtual address space. Location and size, as well as Region's properties, if you write or read-only (such as TEXT Region is read-only), and a pointer to this Region page table, this page table completes the virtual address to physical address Mapping,
This index is in size in size. Sustainable continued. . . . . .
