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 are kernels and what do kernels do, What are kernels and what do kerne...

What are kernels and what do kernels do? The kernel is a program that comprises the central core of a computer operating   system. It has entire control over everything that

What is the kernel, What is the kernel? A more common explanation is th...

What is the kernel? A more common explanation is that the OS is the one program running at all times on the computer  usually known as the kernel, with all else being applicati

What is a buddy system?, What is a buddy system? We are dividing the me...

What is a buddy system? We are dividing the memory as powers of two therefore the division will be 2, 4, 8, 16, 32, 64, 128, 256...i.e. in powers of 2 as well as we are selecti

Define paging , Paging: Only the needed memory pages are moved to main me...

Paging: Only the needed memory pages are moved to main memory from the swap machine for execution. Process size does not matter. Produce the concept of the virtual memory. It

Selection of a disk-scheduling algorithm, Q. How would utilize of a RAM di...

Q. How would utilize of a RAM disk affect your selection of a disk-scheduling algorithm? What factors would you require to consider? Do the similar considerations apply to hard-di

Explain about operating system services, Q. Explain about Operating System ...

Q. Explain about Operating System Services? An operating system offers services to programs and to users of those programs. It provided by one environment for execution of

Differentiate pre-emptive and non-preemptive scheduling, Differentiate pre-...

Differentiate pre-emptive and non-preemptive scheduling In a pre-emptive scheduling technique, CPU can be taken away from a process if there is a requirement while in a non-pre

Unix and linux commands, To explore the UNIX file system, use basic UNIX co...

To explore the UNIX file system, use basic UNIX commands and use a text editor. Task:   1.      Logon to Linux. 2.      Create a directory "Unix" under your home d

Define fifo page replacement algorithm, Define FIFO Page Replacement Algori...

Define FIFO Page Replacement Algorithm This policy simply eliminates pages in the order they arrived in the main memory. By using this policy we simply remove a page based upo

Virtualization, What factors are involved in choosing the host operating sy...

What factors are involved in choosing the host operating system?

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