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

Differences between symmetric and asymmetric multiprocessing, Describe the ...

Describe the differences between symmetric and asymmetric multiprocessing. What are three advantages and one disadvantage of multiprocessor systems? Symmetric multiprocessing t

Explain the fork function, Explain the Fork Function Fork function caus...

Explain the Fork Function Fork function causes a new process to be created. The calling progress is duplicated as an exact copy (called the child process) that differs only in

Dynamic memory management, Usually memory is allocated from a large pool of...

Usually memory is allocated from a large pool of unused memory area called the heap. In C++, dynamic allocation/deallocation must be manually performed using commands like malloc,

What are the operations of processes, What are the operations of processes?...

What are the operations of processes? Process creation A process may create several new processes. The creating process is called as parent process, where as the new proce

Enforce memory protection at compile time?, Why is it not possible to enfor...

Why is it not possible to enforce memory protection at compile time?   Every process should be protected against unwanted interference by other process, whether intentional or

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

Operation management, trace the historical evolution of the operations mana...

trace the historical evolution of the operations managent from themainly rural agricultural era of the artisans to the present day industrial revolution, high technoligical advance

Explain clustered file organization, Clustered file organization A cl...

Clustered file organization A clustered file is also called a B-tree-clustered file is a tree-structured file in which records with adjacent index values are clustered toget

What are the advantages of contiguous allocation, What are the advantages o...

What are the advantages of Contiguous allocation? The advantages are a. Supports direct access b. Supports sequential access c. Number of disk seeks is minimal.

Explain gui based operating system, GUI - Short for Graphical User Interfa...

GUI - Short for Graphical User Interface a GUI Operating System contains icons and graphics and is commonly navigated by using a computer mouse. Below are some instances of GUI Op

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