Hi Ran,

On 2026-03-13T11:26:12+0200, Ran Benita wrote:
> TCP_DEFER_ACCEPT has an interesting little-known effect on client
> sockets. I don't think it's very useful but should still be documented.
> 
> See here for reference:
> <https://elixir.bootlin.com/linux/v6.19.6/source/net/ipv4/tcp_input.c#L6781-L6796>
> 
> Signed-off-by: Ran Benita <ran@unusedvar.com>

Thanks!  I've applied the patch.


Have a lovely night!
Alex

> ---
> Thanks for taking a look. I fixed the following:
> - Change non-zero -> nonzero
> - Use semantic newlines
> 
>  man/man7/tcp.7 | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/man/man7/tcp.7 b/man/man7/tcp.7
> index adfd6623e..80b91ffda 100644
> --- a/man/man7/tcp.7
> +++ b/man/man7/tcp.7
> @@ -1091,6 +1091,12 @@ Allow a listener to be awakened only when data arrives on the socket.
>  Takes an integer value (seconds), this can
>  bound the maximum number of attempts TCP will make to
>  complete the connection.
> +.IP
> +On a client socket, if nonzero,
> +delays sending the final ACK of the three-way handshake until the socket has data to send,
> +in which case the ACK is piggybacked on the first data segment,
> +or a delayed-ACK timeout is reached.
> +.IP
>  This option should not be used in code intended to be portable.
>  .TP
>  .BR TCP_INFO " (since Linux 2.4)"
> -- 
> 2.53.0
> 

-- 
<https://www.alejandro-colomar.es>