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.
A hard-disk drive reads “120 GB HDD 7200 rpm 3 GB/sec transfer rate”. If the drive has a sector size of 512 bytes, what is the average rotational latency and transfer time to read
advantages and disadvantages of monolithic and layered approach
Define Ageing Ageing is a method of enhancing the priority of process waiting in Queue for CPU allocation
List operations to be performed on directories. Search for a file, delete a file, create a file, list a directory, rename a file, and traverse the file system.
explain in detail about ipc in linux
Describe paging technique used in UNIX systems. When a process begin in UNIX, not every its memory pages are read in from the disk at once. In its place, the kernel loads into
What is page fault and what are the steps taken by the OS to remove page fault? A page fault is caused while a page that hasn't been brought into memory is being addressed. The
In fixed portioning scheme, what are the advantages of using unequal- size partitions? With unequal-size partitions there are two probable ways to assign process to partitions.
function of lazy swapper
what is system performence?
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