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

Changing the runlevel of system from 5 to 3 on startup, Front page We n...

Front page We need to continue or customization and documentation of our system. Currently our system boots into runlevel 5 and we need it to boot into runlevel 3. For future r

Explain message passing among systems, Q. Explain Message passing among sys...

Q. Explain Message passing among systems? Communications- Message passing among systems requires messages to be turned into packets of information and sent to the network contr

What is an operating system process, What is an operating system process? H...

What is an operating system process? How is it different from a program? Why do we need the concept of a process, rather than simply talk about programs running in memory? The e

Compute the effective instruction time on the system, Q. An operating syst...

Q. An operating system sustains a paged virtual memory using a central processor with a cycle time of 1 microsecond. It costs an additional one microsecond to access a page other

What are the benefits of thread pools, What are the benefits of thread pool...

What are the benefits of thread pools:- The benefits of thread pools are 1. It is usually faster to service a request with an existing thread than waiting to make a thread.

Operating System, my Operating System is windows trust but when the windows...

my Operating System is windows trust but when the windows start say its windows xp. help pleaes

Characteristics of suspend process, Characteristics of suspend process ...

Characteristics of suspend process Suspended process isn't immediately available for execution. The process may or may not be waiting on an event. For preventing t

Protection scheme in unix, Q. Consider a system that holds 5000 users. Pre...

Q. Consider a system that holds 5000 users. Presume that you want to allow 4990 of these users to be able to access one file. a. How would you denote this protection scheme in

Bind a real-time thread to an lwp, Q. Suppose an operating system maps user...

Q. Suppose an operating system maps user-level threads to the kernel utilizing the many-to-many model where the mapping is done through the use of LWPs. In addition the system allo

Homework, Write an application that does the following:(1) fill an array wi...

Write an application that does the following:(1) fill an array with 50 random integers; (2) loop through the array, displaying each value, and count the number of negative values;

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