Unfamiliar items in the log - RT-AC87R

I have not seen these before with my RT-N66U, but they are appearing in large numbers, over and over in the AC87R. What are they related to?

Jul 21 18:46:21 kernel: HTB: quantum of class 110256 is small. Consider r2q change.
Jul 21 18:46:22 kernel: HTB: quantum of class 120001 is big. Consider r2q change.
Jul 21 18:46:22 kernel: HTB: quantum of class 120256 is small. Consider r2q change.
Jul 21 18:46:22 kernel: HTB: quantum of class 130001 is big. Consider r2q change.
Jul 21...

Unfamiliar items in the log - RT-AC87R