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.
advantage and dis advantage of threads
Safety algorithm : This is to make sure if the system is in safe state or not. It may need an order of m x n2 operation to determine if the state of the system is safe or not.
How Memory utilization factor shall be computed Memory utilization factor shall be defined as Memory in use/total memory connected
There are three kinds of Data Abstraction: Physical level: The minimum level of abstraction defines how data are saved. Logical level: The next bigger level of a
Q. Show that a few schedules are possible under the two-phase locking protocol however not possible under the timestamp protocol and vice versa. Answer: A schedule that is auth
what is file?explain the file access methods?
Determine what the “blocking factor” of a file is Blocking factor is the number of logical records in one physical record
What are the steps followed in testing? i. Unit testing - The individual components are tested in this type of testing. ii. Module testing - Related collection of independen
The performance of a file system depends upon the cache hit rate (fraction of blocks found in the cache). If it takes 1 msec to satisfy a request from the cache, but 40 msec to sat
MEMORY MANAGEMENT USING LINK LISTS The first one is for showing it is process or hole, second is for starting address and third is for length of the process and last is a point
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