Permanently resident pages - main memory, Computer Engineering

Assignment Help:

Permanently resident pages:

Every virtual memory systems have memory areas that are "pinned down", for example cannot be swapped out to secondary storage, for instance:

  • Interrupt mechanisms usually rely on an array of pointers to the handlers for different types of interrupt (I/O completion, program error, timer event, page fault, etc.). If the pages containing these pointers or the code that they invoke were page able, interrupt-handling would become even more complicated and time-consuming; and it would be especially hard in the case of page fault interrupts.
  • The page tables are typically not page able.
  • Data buffers that are accessed outside of the CPU, for instance by peripheral devices that use direct memory access (DMA) or by I/O channels. Typically such devices and the buses (connection paths) to which they are connected use physical memory addresses rather than virtual memory addresses. Even on buses  with  an  IOMMU,  that  is  a  special  memory  management  unit  that  may  translate  virtual addresses used on an I/O bus to physical addresses that transfer can't be stopped if a page fault take place and then restarted when the page fault has been processed. So pages that contain locations to which or from which a peripheral device is transferring data are either enduringly pinned down or pinned down whilst the transfer is in progress.
  • Timing-dependent kernel/application cannot stand the varying response time caused by paging.

1356_Permanently resident pages.png


Related Discussions:- Permanently resident pages - main memory

Explain the working of broad band isdn, Explain the working of broad band I...

Explain the working of broad band ISDN. BISDN Configuration: Figure shows how access to the BISDN network is accomplished. All peripheral devices are interfaced to the acces

Operations of a scientific calculator, A program is to be developed to simu...

A program is to be developed to simulate the operations of a scientific calculator. List the facilities to be provided by this calculator. Analyze this using a DFD 0- level and 1-

What is parallel sections construct, What is Parallel Sections Construct? ...

What is Parallel Sections Construct? The parallel sections construct is a shortcut for specifying a parallel construct comprising one sections construct however no other statem

Mac and llc, how can we improve the way LLC and MAC are used for LAN operat...

how can we improve the way LLC and MAC are used for LAN operation.?

Time complexity in the worst case, Speicified the following piece of code: ...

Speicified the following piece of code: int i = 1; int j = 4; while (i     {      if (i%3 == 0) i+=3;      else i+=4;        if (j%2 == 0) j*=4;      els

Define windows authentication, Windows Authentication This provider uti...

Windows Authentication This provider utilizes the authentication capabilities of IIS. After IIS completes its authentication, ASP.NET uses the authenticated identity's token to

Explain about annotational notations, Explain about Annotational Notations ...

Explain about Annotational Notations These notations may be applied to describe remark and illuminate about any element in the model. They are considered as explanatory of U

Are there standards for electronic imaging, Are there standards for electro...

Are there standards for electronic imaging? Given the sensitive nature of most permanent records, there are microphotography standards in place which contain microfilm, compute

Why does microprocessor contain rom chips?, Microprocessor have ROM chip be...

Microprocessor have ROM chip because it have instructions to implement data. It have the monitor program which not only include implementation instruction but also interfacing

State the benefits of encapsulation, State The Benefits of Encapsulation ...

State The Benefits of Encapsulation To hide the details of a class, you can declare that data or implementation in the private part of class so that other class clients will n

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