To make it short, conky is used for monitoring your system. If you're about to be out of RAM, you probably want to see a RAM bar approaching 100%, right?
That would need accounting for tmpfs and other shared memory: if you fill a tmpfs, or use postgresql with big shared_buffers, you'll be out of RAM and linux will start killing apps with conky saying you're using 10% of your RAM!
This patch provides accounting for this at approximately zero cost.
It it thoroughly commented, but for more info, see: http://calimeroteknik.free.fr/blag/?article20/really-used-memory-on-gnu-linux
Merged: https://github.com/brndnmtthws/conky/pull/54
Can be closed.