Yes, the point of "async" isn't to save CPU cycles, it's to customize the scheduler so that you can prioritize resource use properly. (E.g., don't switch to th

Yes, the point of "async" isn't to save CPU cycles, it's to customize the scheduler so that you can prioritize resource use properly. (E.g., don't switch to the systemd or sshd thread if a customer's web request is timing out.) That said, doing this right is out of reach of the average programmer, and it's doubtful that the compiler has enough domain-specific knowledge to do this automatically. "Async" of the Python and node.js fame is yet another thing, a hack to get around their interpreters' inability to use kernel multitasking features because of global locks.