Taking CPU cores offline while under load makes them unable to unload?

I have an AMD Ryzen 5 5625 U CPU with 6 physical cores and 12 SMP cores. I'm running Zorin Core OS 16.2r-1. I've been testing ways of saving more power on a laptop. Ultimately I'd like to be able to park cores that are idle or below a user-configurable percentage load (the machine idles at 400 MHz CPU frequency, with 6 cores at 0% and 6 cores flipping between 1% and 0%). I'm using: for i in $(seq $(getconf _NPROCESSORS_ONLN)); do yes > /dev/null & done ... to impose a load upon all the cores, then I use powertop and powerstat to measure the power drawn. I kill that via: sudo killall yes One thing I noticed is that if I do: for x in /sys/devices/system/cpu/cpu{1..11}/online; do echo 0 >"$x"; done ... to take all but Core0 offline (Core0 can't be taken offline), while the CPUs are loaded using yes, the cores taken offline don't unload even after yes is killed... the cores remain at 100% (as shown in Conky ${cpubar cpuX 10,115} and ${freq X} and ${cpu cpuX} where 'X' is the CPU number) until I bring those cores back online via: for x in /sys/devices/system/cpu/cpu{1..11}/online; do echo 1 >"$x"; done Is this a bug in Conky such that when a core goes offline, it cannot update the status of that core; or are the cores actually remaining loaded even when taken offline? Powertop and PowerStat can't tell me, as they only measure online cores.