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 to differentiate scheduling algorithms?
Q. Describe why SSTF scheduling tends to favour middle cylinders over the innermost and outermost cylinders. Answer: The middle of the disk is the location having the smalles
Q. Why do some systems stay track of the type of a file while others leave it to the user or simply don't implement multiple file types? Which system is "better?" Answer: A f
Q. In the IBM/370 memory protection is offered through the use of keys. A key is a 4-bit quantity every 2K block of memory has a key (the storage key) associated with it. The CPU
Problem 1. List out the conditions that result in Deadlock situations. Illustrate deadlock situation with a simple graphical notation Listing conditions for deadlock occu
Explain internal fragmentation The Internal fragmentation signifies to the result of reserving a piece of space without ever intending to use it. This space is wasted that this
Process termination A process terminates when it finishes implementing its final statement and asks the operating system to delete it by using the exit system call. At that tim
Explain DosCreateThread Functions Used in the OS/2 DosCreateThread(&threadID,MyThreadFunction,arg,flags,stackSize) DosCreateThread creates a thread within the context of th
explain function of computer operating system?
An analysis, which defines the syntactic structure of the source statement, is known as Syntax analysis defines the syntactic structure of the source statement
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