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If you require a page to be swapped out and must allow for the possibility of it being swapped back in, you need to make sure that the page has the latest changes when it is again swapped in. If changes have been made to a page selected for swapping out, you must save the page to disk. If changes have NOT been made to a page selected for swapping out, you can immediately overwrite memory with a new page, without writing the old page back to disk. Disk access is sl.o..w... . You do not want to spend time writing to disk unless you really have to. The "modified" bit tells you if a change has been made to a page since it has been loaded into memory. As usual, a little bit of information can save you a lot of seek time.
What else can I help you with?
Explain how virtual memory system using demand paging?
Demand paging is a process which involves the copying and relocation of data from a secondary storage system to random access memory (RAM), a main memory storage system. Demand paging copies and relocates data to facilitate the fastest access to that data. Once the data is relocated, demand paging sends a command to the operating system to inform it that the data file or files are now ready to be loaded. Demand paging is performed on demand, or after a command has been sent to retrieve specific data.
What purpose does the referenced bit served in a demand paging system?
It indicates whether the page has been called (referenced) recently. This bit is important because it is used by the LRU algorithm to determine which pages should be swapped out.
What is the best restaurant paging system?
The best paging system is Wendy's drive thru
What is demand paging in Unix?
In computer operating systems, demand paging is an application of virtual memory. In a system that uses demand paging, the operating system copies a disk page into physical memory only if an attempt is made to access it (i.e., if a page fault occurs). It follows that a process begins execution with none of its pages in physical memory, and many page faults will occur until most of a process's working set of pages is located in physical memory. This is an example of lazy loading techniques.
What is page stealing in operating system?
Some Operating Systems periodically look for pages that have not been recently referenced and add them to the Free page queue, after paging them out if they have been modified.
What are the differences between simple paging and virtual memory paging?
In case of simple paging all pages should be in main memory to run a process..while in case of virtual memory paging pages can be loaded as needed by the processor i.e. called demand paging...
What is the normal path of the windows paging file in Windows Vista?
Paging file is located in the root folder of the system drive.
Where can one find a paging system at wholesale prices?
There are a variety of different paging systems that can be purchased at wholesale prices. One can find wholesale paging systems on sites such as Dollar Days and DHgate.
What is paging system implementation?
The question is not very clear - in general the implementation of paging is too complex to answer in a Wiki answer entry; I suggest you take a look at any Operating System theory book.
What is pagging?
Paging is a system of locating the guest. If the guest is not in his allotted room but some where inside the hotel premises, paging is done to locate him the message.
When an operating system spends much of its time paging it is called?
Thrashing
What is the Difference between paging and demand paging in operating system?
paging is the process of memory management in which memory is allocated in the non contiguous form,i.e. the program is break into block of fixed size known as page and also the main memory also break down into block of same size known as frame or page frame. Now all this page are brought into the main memory but in the space available so they can be contiguous if they find whole space required by the program or if the space is available but in scattered form then they can give space in non contiguous form. But in demand paging only those pages are brought into main memory which are required to execute the program at that time when a program need other pages it will swap out the unused pages from the main memory and swap in the desired page thus allowing it to execute the program though the space available is not sufficient to bring the whole program into main memory..................One of the problem arises due to demand paging is page fault which is caused due to required page not found in main memory for which we require swapping. hey if you like my post don't forget to thank me....... for any further queries e-mail me at hemant_spidey3@yahoo.co.in or 1989hemantrajput@gmail.com
