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 segmentation hardware?, Explain segmentation hardware? We defin...

Explain segmentation hardware? We define an completion to map two-dimensional user-defined addresses into one-dimensional physical addresses. This mapping is affected by means

Bag of tasks, The producer-consumermodel above has a standard human analogy...

The producer-consumermodel above has a standard human analogy of an assembly line. Humans have specialized skills, however, whereas threads running the same program do not need to

What is the purpose of system calls, What is the purpose of system calls? ...

What is the purpose of system calls? System calls permit user-level processes to request services of the operating system.

Page fault handling , Page Fault Handling conditions like, where the copy...

Page Fault Handling conditions like, where the copy on write bit of a page is set and that page is send by more than one process, the Kernel assign new page and copies the conten

Briefly explain process management in windows 2000., Briefly explain proces...

Briefly explain process management in Windows 2000. The Windows 2000 process manager provides for deleting, creating and using threads and processes. It has no knowledge about

Race condition, list the prevention of mechanism for race condition with op...

list the prevention of mechanism for race condition with operating system

Illustrate example for segmentation, EXAMPLE FOR SEGMENTATION Consider ...

EXAMPLE FOR SEGMENTATION Consider an instance as given in the table and we have five segments numbered from 0 through 4 the segment is stock in the physical memory as shown. Th

Explain why sstf scheduling tends to favor middle cylinders, Explain why SS...

Explain why SSTF scheduling tends to favor middle cylinders over the innermost and outermost cylinders. The center of the disk is the location having the fewest average distanc

Give an overview of unix based file systems, Give an overview of UNIX based...

Give an overview of UNIX based file systems. UNIX and UNIX-like operating systems allocate a device name to each device, other than this isn't how the files on that device are

What is a multiprocessing system, What is a multiprocessing system? Mul...

What is a multiprocessing system? Multiprocessor systems are those systems that use additional than a single processor for program execution. It is done for raising the executi

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