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.
Is disk scheduling, other than FCFS scheduling, useful in a single-user environment? Explain your answer. In a single-user environment, the I/O queue usually is blank. Requests
Q. In some systems a subdirectory is able to be read and written by an authorized user just as ordinary files can be. a. Explain the protection problems that could arise. b.
Consider the following C program where M, N, K are predefined constants. Assume int is 4 bytes. Suppose this program is run on a machine with 4KB page size and 32 TLB entries. Init
Briefly discuss on real-time scheduling? It is divided into two types. Hard real-time systems are needed to complete a critical task within a guaranteed amount of time. T
Explain the TlsAlloc (VOID) This function is used to allocate a TLS index.Any subsequent TLS function calls will require the handle returned from TlsAlloc to be passed. The i
Advantages and disadvantages of time-sharing operating system
how are you
What is the use of inter process communication. Inter process communication gives a mechanism to allow the co-operating process to communicate with each other and synchronies t
Explain the Spawnvp Function used in the netware Spawnvp(flags, execNmae, argv) This function executes similarly to spawnlp( ) except that parameters are passed as a v
list trhe various classification of model and types?
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