Page Tables
Page table contains the translation information of virtual page number to physical frame number. For an address space of 32 bits and page size of 4 KB (i.e. memory of 2^32 is divided into segments of 4 KB where each segment is called a memory page) , The virtual address will be of size 32 bits of which 12 bits (2^12 = 4 KB) will be used as offset inside a single page whereas remaining 20 bits will be used as virtual page number
Example Memory Access
As it can be seen from the above memory access flow, translating and accessing a virtual page address to actual physical frame address requires 2 memory access which can be slow when the process assumed that it is making only one memory access to fetch data or instruction from memory.
- Page table size is directly proportional to address space size
- Page table size is inversely proportional to a page size