Question

Draw and explain paging model of memory management system.

Answer 1

1. Partitioned memory systems experience external fragmentation because the free memory available is not continuous.
2. Paging allows a program’s memory to be non-contiguous, enabling the program to be placed in physical memory wherever free space is available.
3. Physical memory is divided into fixed-size units known as page frames, while logical memory is divided into blocks of the same size, called pages.
4. When a program is executed, its pages are loaded into any free page frames, and page tables are used to map user pages to memory frames.
5. The page size is determined by the hardware and is usually a power of two. The paging memory model is represented as shown below.
   
6. Every address produced by the CPU is split into two components: a page number (p) and a page offset or displacement (d). The page number is used as an index to access the page mapping table (PMT).