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

Describe what is meant by client-server computing, Question 1: (a) Desc...

Question 1: (a) Describe what is meant by Client-server Computing? (b) Distinguish between a server process and a client process. (c) What are the basic characteristics o

Define a policy for data storage, Produce a referenced four page report whi...

Produce a referenced four page report which describes the possible functionality of the system; similar systems that are out there and different possible approaches to delivering t

Explain busy waiting semaphores, Explain Busy Waiting Semaphores Weak, ...

Explain Busy Waiting Semaphores Weak, Busy-wait Semaphores a) The simplest way to implement semaphores. b) Useful while critical sections last for a short time, or we com

Describe the actions of sun ultra sparc processor, Q. The Sun Ultra SPARC p...

Q. The Sun Ultra SPARC processor has numerous register sets that describe the actions of a context switch if the new context is previously loaded into one of the register sets. Wha

Networking tidbits, There is a very small amount of networking background r...

There is a very small amount of networking background required for Project 2. In Project 2, we want our computer (or our "host") to request information over the Internet from a rem

Briefly discuss on page replacement, Briefly discuss on page replacement? ...

Briefly discuss on page replacement? Page replacement approach is fixed as follows. If no frame is free, we search one that is not presently being used and free it. We can fre

What disadvantages are there to this two-level directory, What disadvantage...

What disadvantages are there to this two-level directory? Without other provisions, two users who require cooperating with each other are hampered in reaching every other's fi

Show the multithreading performance, Q. Provide two programming instances i...

Q. Provide two programming instances in which multithreading provides better performance than a single-threaded solution. Answer: (1) A Web server that services every request

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