Idle - When the CPU currently has no work to do and is waiting to be assigned some new task.Waiting - When the CPU is waiting for new instructions or waiting for a certain input request to be completed.Running - When the CPU is performing tasks actively.Normally, a CPU can exist in four states: When a computer is in I/O wait, it is not performing any computational tasks and is instead waiting for data to be read from or written to a storage device, such as a hard drive or networked file system. I/O wait is the term used to describe a state in which a computer's Central Processing Unit (CPU) is idle, waiting for input/output (I/O) operations to complete. Let’s learn what is I/O wait, the reasons for having such high I/O wait time and the solutions of fixing them in this article. The problem with this seemingly harmless issue is that overtime, this drains our kernel and bogs down our CPU thus resulting in poor performance. Ideally, our CPU doesn't seem to do any work when it is processing one input request at a time, thus the duration between your input and the output provided by the system can be treated as the I/O wait time. Speaking in layman terms, I/O wait is the time taken by the processor (here, CPU) to complete an input service request.

Linux cpu monitoring