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 input - output system management, Q. Explain about Input - Ou...

Q. Explain about Input - Output System Management? I/O System Management The module which keeps track of the status of devices is known as I/O traffic controller. Every

Explain busy waiting semaphores, Explain Busy Waiting Semaphores Weak, ...

Explain Busy Waiting Semaphores Weak, Busy-wait Semaphores a) The simplest way to implement semaphores. b) Useful while critical sections last for a short time, or we com

Linux kernel components, Example 1.  The diagram illustrating the data stru...

Example 1.  The diagram illustrating the data structures of in-memory VFS objects and on-disk objects and their relationships on slide 24 of the lecture notes OSD.4. This diagram i

Write a brief note on demand paging, Write a brief note on demand paging. ...

Write a brief note on demand paging. A demand paging is alike to a paging system with swapping. The Processes reside on the secondary memory while we want to implement a proces

Describe the purpose of the open and close operations, Q. Describe the pur...

Q. Describe the purpose of the open() and close() operations. Answer: The open() operation notifies the system that the named file is about to become active. The c

Operating system strectures, with the aid of diagrams describe the followin...

with the aid of diagrams describe the following os structures monolithic , layered, client server

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

What is the cache coherency problem, Question: (a) Modern processors op...

Question: (a) Modern processors operate in one of two modes: one for the operating system and one for applications. What is the purpose of having these two modes? What are

Explain about memory-management scheme, Q. In the IBM/370 memory protectio...

Q. In the IBM/370 memory protection is offered through the use of keys. A key is a 4-bit quantity every 2K block of memory has a key (the storage key) associated with it. The CPU

Write a program to synchronize the agent, The Cigarette-Smokers difficulty ...

The Cigarette-Smokers difficulty Consider a system with three smoker processes and one agent process. Every smoker continuously rolls a cigarette and then smokes it. But to roll as

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