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) Describe services of operating systems. (b) Differentiate among the short term, medium term and long term scheduling that are given by multi-tasking operating systems.
What is the information associated with an open file? Various pieces of information are associated with an open file which may be: File pointer Disk location of th
What are the operations of processes? Process creation A process may create several new processes. The creating process is called as parent process, where as the new proce
Explain the Spawnlp Functions Used in the NetWare Spawnlp(flags, execName, arg0,...) The Spawnlp function is used to load a NetWare executable file (NLM) specified by exec
One reason to learn C and C++ is simply that so much software is written in these languages. A related, butmore fundamental reason, is that C and C++ are relatively low-level, allo
What are over lays? If a large process enters which is huge than the available memory we are able to use overlays. In this we can divide process into pieces .which is recognize
What are the system components of an operating system and explain them? a) Process management b) Main-memory management c) I/O management d) File management e) Seco
What do you mean by system calls? System calls give the interface among a process and the operating system. When a system call is implemented, it is treated as by the hardware
best fit
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
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