1. A memory swapping method comprising: receiving queue information for a memory swapping task from a host device; performing part of the memory swapping task in a storage device based on the queue information; receiving a command corresponding to the queue information from the host device after said performing of the part of the memory swapping task is completed; and performing a remaining part of the memory swapping task according to the command by using a result of the part of the memory swapping task previously performed.