swapoff錯誤Cannot allocate memory

I found out why swapoff fails; and its because the amount of swap file being used is bigger than what can fit in the my RAM 

In other words, when we do swapoff; all that is stored in the swap will be moved to the amount of free RAM available. 
If the free RAM available is less than the swap being used, the system cant turn off the swap because it needs to 'dump' it to the RAM 

In other words if you have 512 of ram and you only have 100mb of that ram available and your swap is using 300mb, you cant swapoff because the 300mb of the swap wount be able to fit in the free 100mb of the RAM. 

To test this i killed most applications that i wasnt using at the time and tried to lower the amount of RAM and SWAP being used at the moment. 

Once the i was able to free enough RAM i was able to swapoff it no issues. 

This problem is solved.