On Sep 1, 5:54 pm, Terry Reedy <tjre... at udel.edu> wrote: > > Does it mean that python threads are not mapped to the core in the system. > > They all run on the same core. > No, CPython is a native thread implementation, so they'll be scheduled however the kernel sees fit. Only allowing one thread to run at a time doesn't mean they'll always run on the same core. Adam