multiple cores

Process/Thread per CPU

$ ps -e | grep migration
$ ps -e | grep ksoftirq
$ ps -e | grep cpuhp
$ ps -e | grep idle_inject
$ ps -e | grep kworker (multiple per cpu)

kernel stack running at ring 0

each process has two stacks user space stack kernel space stack

separation: if the user stack is corrupted, we don’t want the kernel clobbered