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.
Problem: a) The CPU can access 2 storage devices directly. What are these 2 storage devices? b) Define 2 key issues involved in memory management. c) How do processes sha
As we have discussed, page tables map virtual page addresses to physical page addresses. One of the advantages of using virtual addresses is that we can achieve complete separation
Question : (a) In the demand paging system, when a process tries to access a page that was not brought into memory, a page fault occurs that involves a series of actions. The
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
what is deadlock
what are the threds in operating system?
basic advantage of using interrupt initiated data transfer over transfer under program control without an interrupt
Partitions and mounting A disk can be sliced into many partitions, or a partition can span multiple disks. Every partition can be either "raw", having no file system, or "cooke
Q. Describe the purpose of the open() and close() operations. Answer: The open() operation notifies the system that the named file is about to become active. The c
Allocators can also be used to avoid problems with unsafe languages. C and C++ are pervasive, with huge amounts of existing code. They are also memory-unsafe languages, in that the
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