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

Microsoft, Discuss the high barriers to entry in the market for PL operatin...

Discuss the high barriers to entry in the market for PL operating systems

Define disadvantages of top down parsing of backtracking, Define Disadvanta...

Define Disadvantages of Top Down parsing of Backtracking The disadvantages of top down parsing of backtracking: (i)  Semantic actions cannot be carried out while making a pr

What is two-level directory, What is Two-level directory In the two-lev...

What is Two-level directory In the two-level directory structure every user has own user file directory (UFD). When a user jobs begins or a user logs in, the system's master fi

Explain fifo page replacement, Explain FIFO page replacement A FIFO rep...

Explain FIFO page replacement A FIFO replacement algorithm associates with every page the time when that page was brought into memory. When a page must be changed, the oldest p

Unix, difference between soft link and hard links

difference between soft link and hard links

Explain structure, Explain Structure The Grammar for programming langua...

Explain Structure The Grammar for programming language is a formal description of Structure

Find the optimal solution and optimal value, Find the optimal solution and ...

Find the optimal solution and optimal value of the following linear program. Use both (a) the enumerating the corner points method and (b) the iso-profit line method. Also identify

THREADS, advantage and dis advantage of threads

advantage and dis advantage of threads

List post-installation procedures that need to be performed, Problem: (...

Problem: (a) Based on your experience in setting up Windows 2003 Server operating system, briefly describe the twelve different steps in which the installation is conducted du

Explain a computing environment, Q. Polling for an I/O completion is able ...

Q. Polling for an I/O completion is able to waste a large number of CPU cycles if the processor iterates a busy-waiting loop several times before the I/O completes. However if the

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