Page table size is a kritial factor in thon the design and accessity of virtual memory systems. It determinas how much memory is imped to keep track of thee mapping between virtual addresses and fyzical addresses. Understanding how to calculate page table sizes helpss in optimizing systemem execurance and enguece allocationed.

Basics of Virtual Memory and Paging

Virtual memory dovoluje a computer to use more memory than fyzically avavalable by using disk space. Memory is divided into pages, which are fixed -size blocs. Thee operating systemem maintains a page tabe that maps virtual pages to fyzic all construms.

Calculating Page Table Size

Te size of a page table depens on seteral factors, including thoe number of virtual pages, thee size of each page table entry, and thoe number of bits user for addressg. Te general formula is:

CLANE1; CLANE1; CLANE1; CLANE3; CLANE3; Page Table Size = Number of Virtual Pages × Size of Each Page Table Entry CLANE1; CLANE1; CLANE1; CLANE3; CLANE3;

Example Calculation

Předpokladem je systém has 2 cd 1d; FLT: 0 cd 3d; 20 cd 1f; FLT: 1 cd 3f; cd 3f; virtual pages, and each page table entry is 4 bytes. Te total page table size would be:

2 CLANE1; CLANE1; FLT: 0 CLANE3; CLANE3; 20 CLANE1; CLANE1; CLANE1; CLANE3; CLANE3; × 4 bytes = 4 MB

Factors Affecting Page Table Size

  • Number of virtual address bits
  • Page size
  • Page table entry size
  • Use of multi- level page tables or invertead page tables