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 a public key encryption system, Define a public key encryption syste...

Define a public key encryption system Allows just the correct receiver to decode the data

Most wans utilize only a partially connected topology, Q. Most WANs utilize...

Q. Most WANs utilize only a partially connected topology. Why is this subsequently Answer: Cost. A completely connected network requires a link between every node in the netw

Multi-level page tables, Multi-level page tables are tree-like structures t...

Multi-level page tables are tree-like structures to hold page tables. As an example, consider a two- level page table, again on a 32-bit architecture with 212 = 4 kbyte pages. Now,

What is the main advantage of multiprogramming, What is the main advantage ...

What is the main advantage of multiprogramming? Multiprogramming makes efficient use of the CPU by overlapping the demands for the CPU and its I/O devices from various users. I

Garbage collection, The dynamic memory allocator is a layer between the app...

The dynamic memory allocator is a layer between the application and the OS, managing heap objects. When a program requests memory from the allocator (via malloc(), for instance), t

What are the five major activities of an operating system, What are the fiv...

What are the five major activities of an operating system in regard to process management? The creation and deletion of both user and system processes The suspension and res

What is spooling, What is spooling? Spooling overlaps the I/O of single...

What is spooling? Spooling overlaps the I/O of single job with the computation of other jobs.

Advantages and disadvantages of using circuit switching, Q. What are the ad...

Q. What are the advantages as well as disadvantages of using circuit switching? For what types of applications is circuit switching a viable strategy? Answer: Circuit

Explain first fit allocation algorithm, Describe the following allocation a...

Describe the following allocation algorithms: a. First fit b. Best fit c. Worst fit   a. First-fit: search the list of available memory and all

Explain the procedure for handling the page fault, The procedure for handli...

The procedure for handling the page fault is as follows 1. We check the internal table to verify whether the reference was valid or invalid. 2. If the reference was invalid,

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