Virtual memory, Operating System

Assignment Help:

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 physical address. Why would one do this? Here are some of the reasons that virtual memory is useful:

 To isolate and protect processes from each other,

 To manage the limited physical memory ef?ciently,


To give each process the illusion of having the whole address space for itself.

Since each program thinks it has the whole memory to itself, programs can use a lot of virtual memory. In fact, a computer might use huge amounts of virtual memory, much more than the amount of actual physical memory available. Most of the time this works fairly well, since processes typically only need to use a small amount of their virtual memory at once, and often a lot can be shared among processes (such as with shared libraries). But if the system gets into a situation where the active virtual memory demands exceed the available physical memory, we will need to use another mechanism, such as "swapping" memory pages to disk.

Virtual memory uses one level of indirection in the translation from virtual addresses to physical addresses.


Related Discussions:- Virtual memory

Diehard allocator - custom allocators, Allocators can also be used to avoid...

Allocators can also be used to avoid problems with unsafe languages. C and C++ are pervasive, with huge amounts of existing code. They are also memory-unsafe languages, in that the

What is indexed allocation, What is indexed allocation? Every file has ...

What is indexed allocation? Every file has its own block of pointers to the sectors of the file.

Explain the various methods of file access, Operating Systems 1. Illust...

Operating Systems 1. Illustrate the Microkernel Architecture with suitable diagram. 2. When Deadlock occurs? What are the Necessary Conditions for Deadlock? 3. Describe f

Quantum settings denoted by q, Determining the time quantum for a job is a ...

Determining the time quantum for a job is a critical task. Given the assumptions that the average switching time between processes is s, and the average amount of time an I/O bo

Transportation, what are the factors influencing the choice of a mode of tr...

what are the factors influencing the choice of a mode of transportation?

Calculate the maximum file size , A UNIX file system has 1-KB blocks and 4-...

A UNIX file system has 1-KB blocks and 4-byte disk addresses. What is the maximum file size if i-nodes contains 10 direct entries, and one single, double, and triple indirect entry

What is an operating system, What is an operating system? An operating ...

What is an operating system? An operating system is a program that manages the computer hardware. It acts as an intermediate among users of a computer and the computer hardware

Tree directory structure, please help us to write a code in c for tree dire...

please help us to write a code in c for tree directory structures.

What is the purpose of the global catalog, Question: (a) i. Consider A...

Question: (a) i. Consider Active Directory as a database, then for each type and new class of objects, what is created? ii. What is the purpose of the global catalog? ii

Blocking locks, We have talked about blocking locks, which voluntarily yiel...

We have talked about blocking locks, which voluntarily yield, and spinlocks, which just spin until they acquire the lock. At ?rst, it seems like spinlocks are verywasteful, and tha

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd