What does the deferred option mean in NGINXs listen directive?

Question

I've seen example NGINX configurations with the "deferred" option added to the listen directive

server {    listen 80 default deferred;   ...  } 

I can't work out what it does (and whether or not I should use it) and the documentation doesn't make too much sense to me

deferred -- indicates to use that postponed accept(2) on Linux with the aid of option TCP_DEFER_ACCEPT

Can anyone explain what this option is for?

Answer 1

TCP_DEFER_ACCEPT can help boost performance by reducing the amount of preliminary formalities that happen between the server and client.

You can read more about it HERE.