关于YIELD指令的一点点疑问

看ARMv8手册，发现一段关于YIELD的描述：

The YIELD instruction has no effect in a single-threaded system, but developers of such systems can use the
instruction to flag its intended use for future migration to a multiprocessor or multithreading system. Operating
systems can use YIELD in places where a yield hint is wanted, knowing that it will be treated as a NOP if there is no
implementation benefit.

问题：线程的调度不应该是内核做的事情吗？某个核执行线程YIELD指令是怎样影响OS内核调度的？