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

State about the directed-test methodology, Directed-Test Methodology Bu...

Directed-Test Methodology Building a directed verification environment with a comprehensive set of directed tests is very time-consuming and difficult. As directed tests only c

Multithreaded architecture, Multithreaded Architecture:  It is clear now th...

Multithreaded Architecture:  It is clear now that if we give many contexts to multiple threads, then processors with multiple contexts are known as multithreaded systems. These sys

Ip fragmentation of user datagarm, IP specified that datagram can arrive in...

IP specified that datagram can arrive in a different order than they were sent. If a fragment from one datagram arrives at a destination before all the segments from a previous dat

What is the task of the pass 2 in a two-pass assembler, In a two-pass assem...

In a two-pass assembler, the task of the Pass II is to? Ans. The task of the Pass II is to synthesize the target program in a two-pass assembler.

What is error checking, What is error checking? It computes the error c...

What is error checking? It computes the error correcting code (ECC) value for the data read from the given sector and compares it with the corresponding ECC value read from the

What is difference between hold time and setup, What is difference between ...

What is difference between hold time and setup? The interviewer was looking for one exact reason, and it’s really a good answer as well..The hint is hold time doesn't depend onto c

What do you mean by shopping bots, Q. What do you mean by shopping bots? ...

Q. What do you mean by shopping bots? ANSWER: A shopping bot or buyer agent is an intelligent agent on a Web site that assists you, the customer, search the products and servic

Neural networks as perceptrons, Neural networks as perceptrons: Howeve...

Neural networks as perceptrons: However ANNs look like this in the general case:  Considered that the w, x, y and z represent real valued weights so all the edges in t

Compute physical address of data byte, Q. Compute Physical address of data ...

Q. Compute Physical address of data byte? Offset of data byte = 0020h Value of data segment register (DS) = 3000h Physical address of data byte   This computation

Explain message, Differentiate between message switching, packet switching ...

Differentiate between message switching, packet switching and circuit switching Message switching: Recourse computer sends data to switching office that stores the data in

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