In-depth understanding of computer operating systems--9th: caching, Memory management

9.3 Virtual memory as a caching tool

(1) The virtual memory is organized into an array of n contiguous byte-sized cells stored on disk.

(2) Each byte has a unique virtual address, as an array index

(3) The contents on the disk are cached in main memory

(4) The data on the disk is partitioned into chunks as a transmission unit between the disk and main memory

Virtual pages:

(1) The VM system splits the virtual memory into a fixed block of the size of the virtual page

(2) The size of each virtual page is p=2^p

Physical page:

(1) Similar physical memory is also divided into physical pages, and the size is p called page frame

A collection of virtual pages:

(1) Unassigned: No data is associated with it, and no disk storage space is consumed

(2) Not cached: The allocated pages in the physical memory are not slow to exist

(3) Cached: Cached pages in physical memory currently in slow existence

Medium: 1,4,6 is already assigned page, 0,3 is not assigned, 2,5,7 is already allocated but not cached

In-depth understanding of computer operating systems--9th: caching, Memory management