Because interrupt processing is typically a non-preemptible task in time-sharing operating systems, an interrupt storm will cause sluggish response to user input, or even appear to freeze the system completely. This state is commonly known as "live lock". In such a state, the system is spending most of its resources processing interrupts instead of completing other work. To the end-user, it does not appear to be processing anything at all as there is often no output. An interrupt storm is sometimes mistaken for thrashing, since they both have similar symptoms (unresponsive or sluggish response to user input, little or no output).