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 Search for pronunciation examples


 
<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!

  • Luna, 19
    Mexico, Yucatan
    Native language: Spanish
    Foreign language: English, Japanese
    Luna
  • ZIAD, 52
    Jordan, Amman
    Native language: Arabic
    Foreign language: English
    ZIAD
  • mayra, 17
    Colombia, Barranquilla
    Native language: Spanish
    Foreign language: Spanish
    mayra
  • Toms Aranda Luis, 68
    Mexico, Ciudad De México
    Native language: Spanish
    Foreign language: English
    Toms Arand...
  • klara, 48
    Kazakhstan, Astana
    Native language: Russian
    Foreign language: English
    klara
  • eilyn, 35
    Venezuela, Valencia
    Native language: English
    Foreign language: French
    eilyn
  • alejandro, 26
    Cuba, Matanzas
    Native language: Spanish
    Foreign language: English
    alejandro
  • Esthefany, 23
    Venezuela, Guayana
    Native language: Spanish
    Foreign language: English
    Esthefany
  • Fernanda Ramirez, 25
    Colombia, Bogotã¡
    Native language: Spanish
    Foreign language: English
    Fernanda R...
  • MIGUEL. G. ARMENDARIZ, 62
    Mexico, Mexico, Distrito Federal
    Native language: Spanish
    Foreign language: English
    MIGUEL. G....
  • Nzenwa irenus, 23
    Nigeria, Lagos
    Native language: Afrikaans
    Foreign language: English
    Nzenwa ire...
  • pepe, 64
    Spain, Córdoba
    Native language: Spanish
    Foreign language: German
    pepe
  • Eвгений, 27
    Ukraine, Нова Ушиця
    Native language: Ukrainian
    Foreign language: English
    Eвгений
  • Walter, 28
    Peru, Lima
    Native language: Spanish
    Foreign language: Portuguese, English
    Soy un Ing. Químico con ganas de aprender y poder compartir experiencias en diferentes idiomas.
    Walter
  • pedro , 22
    Dominican Republic, Sna Cristobal
    Native language: Spanish
    Foreign language: Spanish
    pedro
  • magdalena, 45
    Dominican Republic, Santo Domingo
    Native language: Spanish
    Foreign language: English
    magdalena
  • George, 43
    Colombia, Bogota
    Native language: Spanish
    Foreign language: English
    George
  • Nahumi, 30
    Peru, Lima
    Native language: Spanish
    Nahumi
  • Enrique Napoles Fernandez, 43
    Cuba, Havana
    Native language: Spanish
    Foreign language: Russian
    Enrique Na...
  • luis, 45
    Peru, Lima
    Native language: Spanish
    Foreign language: English
    luis