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.
General Graph Directory A serious trouble with using an acyclic graph structure is making sure that there are no cycles. When links are further added to an existing tree struc
In modern operating systems, applications do not directly access the physical memory. Instead, they use so-called virtual memory, where each virtual address is translated to a phys
Entry-sequenced file organization The records in an entry-sequenced file are store up in the order they are written into the file. New records are for all time appended to
Explain with an example the need of Shift Alteration in critical section problem? Consider processes P i and P j and consider the algorithm for P i and P j .
What is preemptive and nonpreemptive scheduling? Under nonpreemptive scheduling once the CPU has been allocated to a process, the process keeps the CPU unless it releases the C
Define Latency plus seek time The total time to arrange a disk drive mechanism for a block of data to be read from is its Latency plus seeks time
Question 1: (a) Describe what is meant by Client-server Computing? (b) Distinguish between a server process and a client process. (c) What are the basic characteristics o
Applications allocate memory in terms of the number of bytes that they need, but this level of granularity is too ?ne-grained for the operating system to manage the system memory i
Ask question #Minimum 100 words accepted application of bounded and unbounded buffers
What components of the R/e system initiate the start of background jobs at the specified time? The batch scheduler initiates the begin of background job. The dispatcher then s
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