This is an old desktop I use for some small self hosting services. I never use all my RAM and I don't see any RAM spikes other than when I install/compile things which I haven't done in months. I restarted the machine a couple of times, but the SWAP will eventually go right back up to 100%.
I have an Ubuntu server/yunohost setup and found: https://askubuntu.com/questions/157793/why-is-swap-being-used-even-though-i-have-plenty-of-free-ram
My cat /proc/sys/vm/swappiness value is indeed 60. Im not sure what would reduce the SWAP space usage.
Would changing this swappiness value help? Anyone come across this issue before?
EDIT: Found out what it is, its the matrix server that is running on the system. Its taking up a significant amount of swap. Found out via:
smem -s swap -r -p
turning that off, the system is now using 90% less SWAP.
/opt/yunohost/matrix-synaps was the process.
Note that often it's more efficient to move infrequently accessed memory for background tasks to swap rather than having to move that out to swap when something requires the memory causing a delay in loading the application trying to get the RAM, especially on a system with lower total RAM. This is the typical behavior.
However, if you need background tasks to have more priority than foreground tasks, or it truly is a specific application that shouldn't be using swap and should be quickly accessible at all times, or if you need the disk space, then you might benefit from reducing the swap usage. Otherwise, let it swap out and keep memory available.