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

What is a pure demand paging, What is a pure demand paging? When starti...

What is a pure demand paging? When starting implementation of a process with no pages in memory, the operating system sets the instruction pointer to the first instruction of t

Explain first fit algorithm, FIRST FIT ALGORITHM Scanning a list along...

FIRST FIT ALGORITHM Scanning a list along with if a free hole is available with necessary space for the process to allocate it allocates the process in that space. The first s

List five services provided by an operating system, List five services prov...

List five services provided by an operating system. Explain how each provides convenience to the users. Explain also in which cases it would be impossible for user-level programs t

Elimination of common sub expression - code optimizatin, Elimination of com...

Elimination of common sub expression during code optimization An optimizing transformation is a rule for rewriting a section of a program to enhance its execution efficiency wi

SYSTEM PROGRAMMING, advantages and disadvantages of monolithic and layered ...

advantages and disadvantages of monolithic and layered approach

System service program, System Service Program system service program S...

System Service Program system service program Supports and provides the services for other program. System service program perform Varity of tasks.  They are further divided in

Different ways in which a thread can be cancelled, What are the different w...

What are the different ways in which a thread can be cancelled? Cancellation of a target thread may happen in two different scenarios: Asynchronous cancellation: One thr

Define process? what is meant by state of a process?, Define process? What ...

Define process? What is meant by state of a process? Process is a program in implementation. A process in general includes the process stack, which consists temporary data and

Explain processing predefined application protocols, Explain Processing Pre...

Explain Processing Predefined Application Protocols Implementing and swift processing of predefined application protocols is sure to improve performance of server - side applic

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