Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Now, let us discuss two related algorithms for deciding which pages to evict. The clock algorithm is one of the most popular choices. It works by keeping frames in a circular structure. (Note that this circle may be very large: a 32-bit machine with 4k pages can have up to 220 1 million frames.) When a page fault occurs, it checks the reference bit of the next frame. If that bit is zero, it evicts that page and sets its bit to 1; if the reference bit is 1, the algorithm sets the bit to 0 and advances the pointer to next frame.
An implementation which is often used in real operating systems is a segmented queue. This type of algorithm divides all existing pages into two sets of pages. The most-active one-third of all pages use a clock algorithm. After that, pages that are evicted out of the clock are moved to a "uncommon" linked list, in which we use exact LRU. This way, we approximate LRU for the frequently-referenced pages (1/3 of the page frames - fast clock algorithm), and at the same time use exact LRU on the infrequently accessed pages (2/3 of all page frames). Since the pages in the uncommon list are not accessed very frequently, it is okay if their accesses are a little slower due to some pointer manipulation.
How does a program execution take place in multiprogramming? While the processor is dealing with a number of programs, the sequence with which programs are implemented will de
Q. Is the Internet a LAN or else a WAN? Answer: The Internet is a WAN as the a variety of computers are located at geographically different places and are connected by long-dis
Q. Is disk scheduling except FCFS scheduling useful in a single-user environment? describe your answer. Answer: In a single-user environment the I/O queue typically is empty.
Evicting the most-recently used (MRU) page does very well on LRU's worst case. In general, however, MRU is a bad idea, since many programs exhibit temporal locality in their memory
1. Problem Domain You will be considering the Wumpus world introduced in Russell and Norvig (2009) Chapter 7. For this programming assignment you'll use Prolog's ability to do in
The dynamic memory allocator is a layer between the application and the OS, managing heap objects. When a program requests memory from the allocator (via malloc(), for instance), t
Transparency Users must be able to access remote resources as though these resources were local. Transparency should as well promote user mobility. Users must be allowed
Fault tolerance : Machine failures, Communication faults, storage device crashes, and decays of storage media must be tolerated by the system to some extent. A fault tolerant sy
Q. Give an instance of an application in which data in a file should be accessed in the following order: a. Sequentially b. Randomly Answer: a. Print the content of
Producer-Consumer Problem Using Semaphores The Solution to producer-consumer problem use three semaphores namely- full, empty and mutex. The semaphore 'full' is utilized for
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd