Single-level page tables, Operating System

Assignment Help:

As mentioned above, page tables, are lookup tables mapping a process' virtual pages to physical pages in RAM. How would one implement these page tables?

The most straightforward approach would simply have a single linear array of page-table entries (PTEs). Each PTE contains information about the page, such as its physical page number ("frame" number) as well as status bits, such as whether or not the page is valid, and other bits to be discussed later.

If we have a 32-bit architecture with 4k pages, then we have 2 pages, as discussed in the last lecture. If each PTE is 4 bytes, then each page table requires 4 Mbytes of memory. And remember that each process needs its own page table, and theremay be on the order of 100 processes running on a typical personal computer. This would require on the order of 400 Mbytes of RAM just to hold the page tables on a typical desktop!

Furthermore, many programs have a very sparse virtual address space. The vast majority of their PTEs would simply be marked  invalid.Clearly, we need a better solution than single-level page tables.


Related Discussions:- Single-level page tables

Objectives and functions of an operating system, Question: a) What is ...

Question: a) What is an Input/Output module and what are the five categories their functions fall into? b) What is an Operating System? Briefly describe the two objectives

What is the purpose of the virtual memory in windows xp, Question: a) T...

Question: a) The following refers to optimization under Windows XP: i) Give five steps which could undertake to enhance overall system performance in a default Windows XP in

What is a file, Question 1 What is a file? Write down the operations on fi...

Question 1 What is a file? Write down the operations on files Question 2 What do you mean virtual machine? Write down the application of virtual machine Question 3 What

Define field that contain segment index or an internal index, The field tha...

The field that consists of a segment index or an internal index is known as Target datum is field that consists of a segment index or an internal index.

List antivirus techniques used for protection purposes, Question: a) Th...

Question: a) There are main goals of data security. List them and elaborate on how they provide protection. b) Describe threats associated with data security. c) Describe

What are the three major purposes of an operating system, Q. What are the t...

Q. What are the three major purposes of an operating system? Answer: To offers an environment for a computer user to execute programs on computer hardware in a conveni

What is meant by the phrase thread-safe, The term thread-safe in computer p...

The term thread-safe in computer programming describes that routine or portion of the program that may be called from multiple programming threads without uncalled for interactions

How can the deadlock be prevented?, How can the deadlock be prevented? ...

How can the deadlock be prevented? To evade deadlocks first we will have to obtain the information about how resources are to be requested. And as well we should make sure that

What are batch systems?, What are batch systems? Early computers were p...

What are batch systems? Early computers were physically huge machines run from a console. The general input devices were card readers and tape drivers. The common output device

Computers, What is operating system?

What is operating system?

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd