paging - definition

Create account
Where to search:
Thesaurus


Dictionaries » The Free On-line Dictionary of Computing » P »

paging - definition



A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
(Non-alphabetical character)


Free Online Dictionary of Computing - FOLDOC foldoc.org

paging


 
<operating system> A technique for increasing the memory space
available by moving infrequently-used parts of a program's
working memory from RAM to a secondary storage medium,
usually hard {disk.  The unit of transfer is called a page.
 
A memory management unit (MMU) monitors accesses to memory
and splits each address into a page number (the most
significant bits) and an offset within that page (the lower
bits).  It then looks up the page number in its page table.
The page may be marked as paged in or paged out.  If it is
paged in then the memory access can proceed after translating
the virtual address to a physical address.  If the
requested page is paged out then space must be made for it by
paging out some other page, i.e. copying it to disk.  The
requested page is then located on the area of the disk
allocated for "swap space" and is read back into RAM.  The
page table is updated to indicate that the page is paged in
and its physical address recorded.
 
The MMU also records whether a page has been modified since it
was last paged in.  If it has not been modified then there is
no need to copy it back to disk and the space can be reused
immediately.
 
Paging allows the total memory requirements of all running
tasks (possibly just one) to exceed the amount of {physical 
memory}, whereas swapping simply allows multiple processes
to run concurrently, so long as each process on its own fits
within physical memory.
 
(1996-11-22)
 



Permanent link to this page: http://www.diclib.com/cgi-bin/d1.cgi?l=en&base=en_foldoc&page=showid&id=9530


Learn foreign languages chatting with us!

  • Tara, 30
    Vietnam, Ha Noi
    Native language: Vietnamese
    Foreign language: Spanish
    Tara
  • valvos, 45
    Turkey, Istanbul
    Native language: Turkish
    Foreign language: English
    valvos
  • karina
    Ecuador, Guayaquil
    Native language: Spanish
    Foreign language: Spanish
    karina
  • Carlos Francisco Sol Iglesias, 61
    El Salvador, San Salvador
    Native language: Spanish
    Foreign language: English
    Carlos Fra...
  • Milandrys callaars, 17
    Venezuela, Edo. Nueva Esparta
    Native language: Spanish
    Foreign language: Dutch
    Milandrys ...
  • evelyn, 18
    Peru, Lima
    Native language: Spanish
    Foreign language: Spanish
    evelyn
  • alejandro cardenas , 16
    Colombia, Colombia
    Native language: English
    Foreign language: German
    alejandro ...
  • Iosvani More Quintero, 27
    Cuba, Ciego De Avila
    Native language: Spanish
    Foreign language: English
    Iosvani Mo...
  • Jesus
    Mexico, Mexico
    Native language: Spanish
    Foreign language: English
    Soy mas de la mitad mejor de lo que tu crees, con una pizca de maldad menor o igual a la tuya... No he llegado a donde quiero, pero no estoy donde estaba, entonces... todo va como debe!!! I am more than half better than you think, with a hint of evil or less yours ... I have not gotten to where I want, but I&# 39; m not where I was, then ... everything is as it should!
    Jesus
  • David Bolick, 64
    Mexico, Guadalajara
    Native language: English
    Foreign language: Spanish, Portuguese
    David Boli...
  • Ксения, 20
    Russian Federation, Saint Petersburg
    Native language: Russian
    Foreign language: Russian
    Ксения
  • Salkynai, 29
    Kazakhstan, Almaty
    Native language: Russian
    Foreign language: English
    Salkynai
  • linda, 45
    El Salvador, San Salvador
    Native language: Spanish
    Foreign language: English
    linda
  • Wilbert, 36
    Nicaragua, Managua
    Native language: Spanish
    Foreign language: English
    I am from Nicaragua located in central american, I want to learn English because I like so much. thanks for help me
    Wilbert
  • Alisher, 25
    Tajikistan, Dushanbe
    Native language: Russian
    Foreign language: English
    Alisher
  • AnastasiaLagoda, 17
    Russian Federation, Геленждик
    Native language: Russian
    Foreign language: English
    AnastasiaL...
  • TebIndio, 32
    Argentina, Mendoza
    Native language: Spanish
    Foreign language: English
    TebIndio
  • andres, 25
    Dominican Republic, Santo Domingo
    Native language: Spanish
    Foreign language: Spanish
    andres
  • yppv, 17
    Colombia, Bogotã¡
    Native language: Spanish
    Foreign language: Spanish
    yppv
  • Aigul, 23
    Russian Federation, Kazan
    Native language: Russian
    Foreign language: English
    Aigul