I would disagree with that interpretation. I would talk about the duration of the open() call, in the same way as when you&#x27;re optimising code, you talk about the duration of a function call, not its latency.<p>Sadly, misuse of the term is rife in software circles.<p>Latency is correctly used when talking about how long an ISR takes to <i>start</i> running when provoked by an external stimulus, or how long it takes for a task to be scheduled when made ready.<p>Latency is a very precise term. a syscall, as its name suggests is a &#x27;call&#x27;, and &#x27;calls&#x27; are not considered to be instantaneous.<p>(Edit: instantaneous, not atomic)<p>Duration is the correct term for syscalls.