"Blocking" == "can be completed immediately" in this context, ie whether the equivalent syscall would complete immediately or if it would return EAGAIN. So if t

"Blocking" == "can be completed immediately" in this context, ie whether the equivalent syscall would complete immediately or if it would return EAGAIN. So if the operation can be completed immediately, it will be completed in the context of the calling thread without involving the kernel work queue. Otherwise it cannot be completed immediately, so the kernel work queue will take it and start working on it.