Define Swapping technique which is usually used in memory management

 

Define Swapping technique which is usually used in memory management

 

• Swapping is a simple memory/process management technique used by the operating system(os) to increase the utilization of the processor by moving some blocked process from the main memory to the secondary memory(hard disk);thus forming a queue of temporarily suspended process and the execution continues with the newly arrived process.

•  After performing the swapping process, the operating system has two options in selecting a process for execution

• Swapping is a mechanism in which a process can be swapped temporarily out of main memory to a backing store , and then brought back into memory for continued execution.
• Backing store is a usually a hard disk drive or any other secondary storage which fast in access and large enough to accommodate copies of all memory images for all users. It must be capable of providing direct access to these memory images.
• Major time consuming part of swapping is transfer time. Total transfer time is directly proportional to the amount of memory swapped. Let us assume that the user process is of size 100KB and the backing store is a standard hard disk with transfer rate of 1 MB per second. The actual transfer of the 100K process to or from memory will take

100KB / 1000KB per second

= 1/10 second

= 100 milliseconds

 

Here are the example of swapping

 

 



 

Swapping