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

Explain about file allocation methods, Explain about file allocation method...

Explain about file allocation methods? The main problem in direct-access nature is how to assign space to these files so that disk space if utilized effectively and files can b

Computer, what is an operating system?

what is an operating system?

What are two probable uses of these multiple modes, Q. Several CPUs provide...

Q. Several CPUs provide for more than two modes of operation. What are two probable uses of these multiple modes? Answer: Although most systems merely distinguish between use

Explain process scheduling, Explain Process scheduling Process scheduli...

Explain Process scheduling Process scheduling consists of the subsequent sub-functions: 1.      Scheduling : Selects the process to be implement next on the CPU 2.      D

Page-table lookups, How exactly is a page table used to look up an address?...

How exactly is a page table used to look up an address? The CPU has a page table base register (PTBR)which points to the base (entry 0) of the level-0 page table. Each process h

Deadlock-avoidance safety algorithm, Q. Presume that you have coded the de...

Q. Presume that you have coded the deadlock-avoidance safety algorithm as well as now have been asked to implement the deadlock-detection algorithm. Can you do thus by simply usin

Invalid page fault, Invalid page fault :If a page fault happens for a ref...

Invalid page fault :If a page fault happens for a reference to an address that's not part of the virtual address space, so that there could not be a page in memory corresponding

Define programming fundamentals for client- server developer, Define the Pr...

Define the Programming Fundamentals for Client- Server Developers Coding for client - server enforces good programming fundamentals. In order for applications to become client

Information system, using the transformation process model and system think...

using the transformation process model and system thinking concepts explain the key operation of TGL works.

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