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 we have discussed, page tables map virtual page addresses to physical page addresses. One of the advantages of using virtual addresses is that we can achieve complete separation between processes, in terms of address spaces. One drawback to this is that it is convenient to be able to share some things, for example library code which would otherwise be replicated wastefully by many different programs. We don't want to have to load exactly the same library code into every process' address space; we'd prefer to map the library code to its own pages, and let all processes share those pages. This will usually reduce the memory requirements for the system. In order to do this, we need to do some common tricks with page tables.
The ?rst important memory-sharing concept is known as Copy-On-Write, or COW. COW shares pages by default, whenever sharing is still possible. Whenever a new process is created, for example by fork(), we "clone" an old process by making a copy of its page tables and marking all referenced pages as read-only.
Then whenever either of the processes (the original one, or the clone) tries to write to one of the pages, the two processes will differ, and sharing is no longer possible. The OS allocates a new page and changes the mapping in one of the page tables. If neither of the processes ever tries to modify a memory location, however, the processes will share the same (read-only) pages forever! COWtries to maximize the amount of sharing at all times.
Q. a number of systems automatically delete all user files when a user logs off or a job terminates unless the user explicitly requests that they be kept other systems keep all fil
summary of what operating system do
basic advantage of using interrupt initiated data transfer over transfer under program control without an interrupt
Explian Integrating a Request/Response Mechanism Traditional application developers will need to develop a mechanism for communication between requesting (client) and respondin
breifly write a note on about evolution of operating system?
KERNEL-LEVEL THREADS (KLT) In this level every thread management is done by kernel .No thread library except an API system calls to the kernel thread facility exists. The kern
How a virtual memory can be implemented? What are the benefits of using virtual memory?
Explain how the os implements virtual memory phenomenon.
Q. How could a system be designed to allow a choice of operating systems to boot from? What would the bootstrap program need to do? Answer: Delieve a system that would like to
This assignment is based on Programming Project 6.40 in Silbershatz. Implement the ProducerXConsumer program according to the instructions for Project 6.40 for both Linux and Win32
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