Free memory graph is wrong?

[heyimalex]

The free memory graph has this query:

node_memory_MemTotal{instance=~"$server"} - node_memory_MemFree{instance=~"$server"}

Wouldn't that be memory in use?

[cceckman]

+1, came here to say this.

I do like having the graph be mem used rather than mem free. But it should be labelled appropriately.