Paging and Swapping

[Chakravarthi]

Hi,

Please explain me about paging and swapping, What are they, and how they work and what is the difference between them.

Any documents or link on the topic

regards
chakri

[Sajid_1]

This will be a good starting-
http://www.docs.hp.com/hpux/onlinedocs/5965-4641/5965-4641.html

rgds,

[Sajid_1]

Hello,

this document will tell you about swapping:

http://support1.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000048595137

[V. V. Ravi Kumar_1]

hi chakri,
any process, if it is to be excecuted, must be loaded in to the memory(RAM). So depending on the size of the RAM it can accommodate limited no. of processes. but when a new process comes RAM has to provide place for it also. then OS identifies any sleeping process or process which is waiting (for other process to be finished) in the RAM, and swaps it to the virtual memory ( a space on the hard disk, which is called SWAP space) tempororily. Earlier entire process used to be swapped to SWAP space which is called Swaping. But now a new technique called Paging is introduced. here the size of the process will be divided into pages (small chunks like 4kb, 8kb) and these pages will be swapped to SWAP space, which is called Paging.
this is a simple explanation, to got indepth knowledge read manuals as others suggested.

regds

[S.K. Chan]

In a nutshell, swapping is the old terminology of memory management which happens when all pages of a process are moved to the physical disk when other processes need the memory (RAM). Paging on the other hand is a more efficient "swapping" mechanism because it doesn't move all pages of a process out to the disk. Instead it moves those "inactive" pages, thus reduce the overhead. So when these pages are moved from memory to disk it's call pageout and later moved back from disk to memory it's call pagein. You can apply the same argument (swapin and swapout) for swap as well.

[Justo Exposito]

Thanks Animesh good explanation.

Regards,

Justo.

[Rita C Workman]

One of the documents I like can be found at:

/usr/share/doc

..it's called mem_mgt. There are also a number of other papers there that contain an abundance of valuable information to read and learn.

Enjoy,
Rita

[Chakravarthi]

Thanks for info

regards
chakri