System Programming & Operating System - TE

Swapping

Subtopic

Swapping is method of temporarily removing inactive process programs from the physical

memory. Keeping all processes in memory all the time requires a large amount of main memory for

execution of this process, it must be swapped

When process P2 send requests for an I/O operation OS blocked P2 process and will not

return to the ready state for long period of time. Process P2 is in blocked state. Process manager

place the process P2 in blocked this and inform to the memory manager regarding this action

process manager moves a blocked process P1 into the ready state and inform to memory manager.

Process P1 is loaded into main memory by memory manager when there is space available Swapped

out process is stored on the secondary storage disk. It contains executable image with code, data

and stack. Round robin uses swapping concept when swapping creates multiple holes memory, it is

possible to combine them all into by moving all the processes to one side of memory. This technique

is known as memory compaction.

References

• WikiNote Foundation