Cannot find the ionice utility

I am running LEDE on a Netgear R7800 and want to use Syncthing for file synchronization. Once in a while, when Syncthing is busy I get very slow transfer rates from Samba. It looks like Syncthing is overloading CPU and disk IO once in a while and that affects Samba transfers.
I can easily fix the CPU usage by using nice on Syncthing, but I cannot find the ionice utility. Is it not included for a reason or I am not looking in the right place?