[…]Basically, multi-CPU machines are the norm now. You might have multiple packages on the board, which is to say actual distinct chips in sockets. Each one of those might have have multiple cores on board, and each core might have multiple threads (as in hyperthreading). Odds are, if you really have found a “CPU bug”, it will be limited to that core. How do you verify this? Easy: use something like ‘taskset’.[…]

https://rachelbythebay.com/w/2018/04/18/cpu/