有人在有人问是不是要实现类似FreeBSD的ZERO_COPY_SOCKET的时候怒啦，说啦：“I claim that Mach people (and apparently FreeBSD) are incompetent idiots. Playing games with VM is bad. memory copies are _also_ bad, but quite frankly, memory copies often have _less_ downside than VM games, and bigger caches will only continue to drive that point home.”

可是：
a) ZERO_COPY_SOCKET并非默认启用的功能。
b) FreeBSD在7年前就实现了这个功能，某些系统至今连这个选项都没有。
c) FreeBSD的zero_copy manpage明示了其性能影响。

您也老大不小的人了，怎么老改不了这小孩的毛病呢？