There is a loop that busy-waits and will gobble available CPU in the process. That CPU is still available to other processes but it will be used by that loop if nothing else is using it, basically.
If you care slightly less about the responsiveness of that loop then you can change a setting that lets it relax a little.
...but actually, it should default to 1 and be fine.
I thought maybe it was set to 0. Maybe it's something else then.