The swapper works on the biggest scheduling priority. Initially it will look for any sleeping process, if not get then it will see for the ready-to-run process for swapping. But the major need for the swapper to work the ready-to-run process must be core-resident for at least 2 seconds before going out. And for swapping in the process must have been resided in the swap machine for at least 2 seconds. If the need is not satisfied then the swapper will go into the wait state on that event and it is activated once in a second by the Kernel.