Swapus
Swapus is a little software to get processes who use swap.
Install
On debian or ubuntu:
apt install ruby
gem install swapus
How to use
It's simple:
swapus
Output with the swap usage, pid and the command:
144 kB [2119] tmux
256 kB [251] /lib/systemd/systemd-journald
256 kB [1990] ntpd: ntp engine
1088 kB [3253] irssi
1716 kB [275] /lib/systemd/systemd-udevd