Spinlocks are only used for low-level locking, and held for very short periods. A killed process won't die while spinning on a spinlock (or while holding one,

Spinlocks are only used for low-level locking, and held for very short periods. A killed process won't die while spinning on a spinlock (or while holding one, of course) - it will find out the next time it goes into an interruptible wait or returns to userspace.