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

Communications technique - application interaction protocols, Define the Co...

Define the Communications Techniques - Application interaction protocols    Communications techniques are well defined. They give developer the programmatic mechanism to transf

Determine the fork and execlp functions - linux, Assignment What I...

Assignment What I'm covering: General control flow fork() execlp() Parameters Makefiles Additional Questions General Control Flow/fork(

What are the various file operations, What are the various file operations?...

What are the various file operations? The six basic file operations are Creating a file Reading a file Writing a file Repositioning within a file Tr

Index node (inode), A file system depends on data structures about the file...

A file system depends on data structures about the files, beside the file structure. The former is named metadata-data that defines data. Each file is accumulated with an inode, wh

Comparing gc to malloc, Garbage collectors trade space for time. If we coll...

Garbage collectors trade space for time. If we collect all the time (which requires a lot of processing time), the GC allocator will use the least memory possible. On the other han

Malloc and calloc function, Note that the parameter for scanf doesn't need ...

Note that the parameter for scanf doesn't need the address operators & because name is an address. However the variable name has no defined space. This can cause problems within C

Multiprogramming, explain how response time are reduced by allowing time sh...

explain how response time are reduced by allowing time sharing on top of multiprogramming

Show the services which provided by operating system, Q. Show the services ...

Q. Show the services which provided by operating system? A) Resource Allocation: If there are more than one user or jobs running at the same instance then resource

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