You can check the current priority of the swap file from /proc/swaps.
$ cat /proc/swaps
Inorder to change the priority of the swap partitions, you need to edit the “fstab” and append the new priority. If you have the fstab entry for your swap file /swap1 as:
/swap1 swap swap defaults 0 0
then append the following:
/swap1 swap swap pri=x,defaults 0 0 where x is the new priority you have set.
You can re-mount it by using ‘mount -a’ command.