Single-level page tables, Operating System

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.

Posted Date: 3/12/2013 5:38:48 AM | Location : United States







Related Discussions:- Single-level page tables, Assignment Help, Ask Question on Single-level page tables, Get Answer, Expert's Help, Single-level page tables Discussions

Write discussion on Single-level page tables
Your posts are moderated
Related Questions
What are the methods for handling deadlocks? The deadlock problem can be dealt with in one of the three ways: a. Use a protocol to prevent or avoid deadlocks, ensuring that

Questiion 1 Use Priority Scheduling Algorithm to schedule the following processes        Process                 Burst Time             Priority/Time            P1

Gopher Gallery consists of a shopping mall and a cart ride that covers  the 150 acre habitat. There are m visitors and n single-person vehicles. Visitors  stroll around the mall at

Operating Systems 1. Illustrate the Microkernel Architecture with suitable diagram. 2. When Deadlock occurs? What are the Necessary Conditions for Deadlock? 3. Describe f

What is the basic approach of page replacement? If no frame is free is available, find one that is not presently being used and free it. A frame can be freed by writing its con

What is a process? A process is a program in implementation. It is an active entity and it contains the process stack, having temporary data and the data section includes globa

Determine the Requiring Variables on the Scope of a Thread It is very common in server application programs to require variables on the scope of a thread. To provide such a sco

What are the three main activities of an operating system in regard to secondary-storage management? a) Free-space management. b) Storage allocation. c) Disk scheduling.

TII stands for The abbreviation of TII is Table of incomplete instructions.

I need help,i want a brief and easy explanation to understand and write in exams and easy to understand topic of DMA block diagram which Is of I/O management and scheduling? can u