Lxd resource limit

Excuse me for maybe stupid question, but does CPU resource limit really work? I tried to apply allowance limit, ran sysbench and see no difference with 1%-100%. Do I need to install/configure something else? CGroup, etc?
I used this tutorial:

My env is Ubuntu18+ lxd.

sorry for my stupid question, do you understand what is implied by “When using a percentage value, the limit will only be applied when under load” ?

it looks like no:( “sysbench” is not a load? what does it mean “under load”?

it means that when your system is idle, the cpu limitation does nothing. It only kicks in when other processes are trying to use the CPU, to avoid wasting computer power when it’s not needed elsewhere.