I have noticed that after every time I lock my laptop and log back in (or log out and then in), the RAM usage increases with around 100 MB. The reason for this seems to be that
lightdm keeps spawning processes on each lock/relogin and does not kill them properly after a sucessfull login. In the attached screenshot, you can see many
webkit2-greater processes and the RAM usage has reached 1300 MB, only from logging in/out and locking the computer and logging back in.
I saw a couple of threads elsewhere about zombie processes spawned by lightdm and I wonder if this is something that is happening to anyone else using Antergos or if it is unique to my system. It should be easy to test, just lock your screen, log back in and see if the RAM usage has increased with around 100 MB.
I currently using
GDM instead of
lightdm as a workaround. I also tested
sddm and it worked fine as well, only
lightdm seems to have this problem.