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

Define dynamic loading, Define dynamic loading. To obtain better memory...

Define dynamic loading. To obtain better memory-space utilization dynamic loading is used. With dynamic loading, a routine is not loaded until it is called. All routines are ke

Explain threads in details?, What are threads? A thread - sometimes c...

What are threads? A thread - sometimes called as an implementation context or a lightweight process - is a single sequential flow of control within a program. We use threads

State critical section problem, State critical section problem? Discuss thr...

State critical section problem? Discuss three solutions to solve the critical section problem. C-S Problem:- n processes all competing to use some shared data Every

Define seek time and latency time, Define seek time and latency time. T...

Define seek time and latency time. The time taken by the head to move to the appropriate cylinder or track is known as seek time. Once the head is at right track, it must wait

Fork system call in unix, Forking is an important phase of Unix, critical t...

Forking is an important phase of Unix, critical to the support of its design strategies, which encourages the implementation of filters. In Unix, a filter is a process that reads i

Is computers protect the operating system, Q. Some untimely computers prot...

Q. Some untimely computers protected the operating system by placing it in a memory partition that couldn't be modified by either the user job or the operating system itself. Expl

Question 3:, Question 3: (a) Fincorp Ltd is an insurance company wishing t...

Question 3: (a) Fincorp Ltd is an insurance company wishing to change over to a better business system using an improved version of a financial information system (FIS). The direc

The key challenges of distributed systems, Question 1 Explain the followin...

Question 1 Explain the following with respect to Resource Management in Distributed Systems- Task assignment Approach Load - Balancing Approach Load - Sharing Approach

What is segmentation?, What is segmentation? In a segmented memory mana...

What is segmentation? In a segmented memory management scheme a programmer views a program to be collection of program components called as segments. Every segment is a logical

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