Explain Not recently used page replacement algorithm, Computer Engineering

Assignment Help:

Not Recently Used Page Replacement Algorithm

The not recently used abbreviated as NRU page replacement algorithm works on the subsequent principle: while a page is referenced, a referenced bit is set for that page, marking it as referenced. Likewise, while a page is modified (written to), a modified bit is set.  At a specific fixed time interval, the clock interrupt triggers and clears the referenced bit of all the pages, thus only pages referenced in the current clock interval are marked with a referenced bit. When a page requires to be replaced, the operating system categorizes the pages into four classes:

a) Class 0: not referenced, not modified 
b) Class 1: not referenced, modified 
c) Class 2: referenced, not modified 
d) Class 3: referenced, modified.

The NRU (Not recently used) algorithm picks a random page from the lowest category for removal. 


Related Discussions:- Explain Not recently used page replacement algorithm

What is page fault, What is page fault? Its types? Page fault refers to...

What is page fault? Its types? Page fault refers to the situation of not having a page in the major memory when any process references it. There are two kinds of page fault :

What is disk access time, Q. What is disk access time? The disk access ...

Q. What is disk access time? The disk access time has two key components: Seek Time: Seek time is the time for disk arm to move heads to the cylinder comprising the desi

Design issues related to interrupt-driven input - output, Q. Design issues ...

Q. Design issues related to interrupt-driven Input - output? So interrupt handling includes interruption of currently executing program, execution of interrupt servicing progra

Define constraints, Define Constraints Constraints can be defined as P...

Define Constraints Constraints can be defined as Preconditions (input values) and Post Conditions (output values). Preconditions on functions are constraints which input value

What are the values of the slack or surplus variables, Consider the followi...

Consider the following linear programming problem: Minimize:        70M + 40N Subject to:           3M + 7N ≥ 233                             10M + 2N ≥ 254

Global business-to-consumer e-commerce, "Global business-to-consumer e-comm...

"Global business-to-consumer e-commerce sales will pass the 1 trillion euro ($1.25 trillion) mark by 2013, and the total number of Internet users will increase to approximately 3.5

Security, We now consider the relation between passwords and key size. For ...

We now consider the relation between passwords and key size. For this purpose consider a cryptosystem where the user enters a key in the form of a password. Assume a password consi

Computer Graphics , What do you mean by ‘Bresenham’s him Algorithm?

What do you mean by ‘Bresenham’s him Algorithm?

Smtp vs esmtp, what shortcomings of smtp are over come by esmtp?

what shortcomings of smtp are over come by esmtp?

How do you import data from one more access database, The process of import...

The process of importing data from one more Access database follows these common steps they are. ? Preparing the document for import operation and make ensure that extensions ar

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