Userland threads have the advantage of being very fast in the simple case, though the complexities of call conversion eats into this performance advantage for applications that make many system calls.

• 用户态线程的优势是在平常情况下速度非常快，不过在应用程序需要许多系统调用时，调用转换的复杂性抵消了这种性能上的优势。