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

Explain working of the logical file system, Explain working of the logical ...

Explain working of the logical file system The logical file system manages metadata information. Metadata contains all of the file-system structure, excluding actual data. It h

Explain memory management using bit maps, MEMORY MANAGEMENT USING BIT MAPS ...

MEMORY MANAGEMENT USING BIT MAPS   In this memory is separated into different allocation units each of some particular size(a few bites).consider every space of size 4k. A

Financial objective of corporation, The primary financial objective of corp...

The primary financial objective of corporation is usually taken to be the maximization of shareholder wealth. Discuss:- i. Ways in which the shareholder of a company can encour

Explain User-level threads (ult), USER-LEVEL THREADS (ULT) In this lev...

USER-LEVEL THREADS (ULT) In this level the kernel isn't aware of the existence of threads -- All thread management is complete by the application by using a thread library. Th

How can deadlocks be represented?, How can deadlocks be represented? D...

How can deadlocks be represented? Deadlocks are able to be described in terms of a directed graph called as a system resource-allocation graph. This graph contains of the foll

What is the use of fork and exec system calls, What is the use of fork and ...

What is the use of fork and exec system calls? Fork is a system call by which a latest process is created. Exec is also a system call, which is used after a fork by one of the

Main advantages of the microkernel approach to system design, What are the ...

What are the main advantages of the microkernel approach to system design? Benefits typically contain the following  (a) Adding a new service does not require modifying the

Why page sizes always powers of 2, Q. Why page sizes always powers of 2? ...

Q. Why page sizes always powers of 2? Answer: Recall that paging is executed by breaking up an address into a page and offset number. It is most competent to break the address

Which are the different states of a process, Which are the different states...

Which are the different states of a process?   Different status of a process is: New: When the process is created. Running: When instructions are executed. Wait

Explain segmentation and paging, Why are segmentation and paging sometimes ...

Why are segmentation and paging sometimes combined into one scheme? Segmentation and paging are often combined in order to improve upon each other. Segmented paging is helpful

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