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!
As mentioned above, page tables, are lookup tables mapping a process' virtual pages to physical pages in RAM. How would one implement these page tables?
The most straightforward approach would simply have a single linear array of page-table entries (PTEs). Each PTE contains information about the page, such as its physical page number ("frame" number) as well as status bits, such as whether or not the page is valid, and other bits to be discussed later.
If we have a 32-bit architecture with 4k pages, then we have 2 pages, as discussed in the last lecture. If each PTE is 4 bytes, then each page table requires 4 Mbytes of memory. And remember that each process needs its own page table, and theremay be on the order of 100 processes running on a typical personal computer. This would require on the order of 400 Mbytes of RAM just to hold the page tables on a typical desktop!
Furthermore, many programs have a very sparse virtual address space. The vast majority of their PTEs would simply be marked invalid.Clearly, we need a better solution than single-level page tables.
A thread is defined as an independent stream of instructions that can be scheduled to run as such by the operating system. Each program contains a number of threads which can be ru
Additional Reference bits algorithm Here we keep an 8-bit byte for every page in memory. At standard intervals the reference bit is shifted by the OS. If a shift register conta
Define the “turn-around” time of a user job Turn- around time is total time taken to execute the job.
Linked list allocation: At this time the blocks are stored using linked lists. The block size require not be the same. Thus internal fragmentation is avoided. Consider
Q. Suppose that you want to utilize a paging algorithm that requires a reference bit (such as second-chance replacement or working-set model) however the hardware does not provide
Problem: a) Define the term ‘process' and what are the different constituents of a process. b) In the three-state process model, what does each of the three states signify?
Define Middleware to Ease the Low-Level Protocol Burden Fortunately, many products are available today to ease the low-level protocol burden on the application programmer. Midd
Explain what semaphores are, their usage, implementation given to avoid busy waiting and binary semaphores. Semaphore definition Usage for mutual exclusion and process synch
Q. More than one disk drive is able to be attached to a SCSI bus. Especially a fast wide SCSI-II bus can be connected to at most 15 disk drives. Remember that this bus has a bandw
Symmetric multiprocessing To get maximum reliability and efficiency a mode of function called as symmetric multiprocessing is used. In essence, with SMP any program or threads
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