TCP will generally aim to defer the sending of ACKs to minimize the number of
packets on the network. Onload supports the standard
TCP_QUICKACK socket option which allows some control
over this behavior. Enabling TCP_QUICKACK causes an ACK
to be sent immediately in response to the reception of the following data packet. This
is a one-shot operation and TCP_QUICKACK self clears to
zero immediately after the ACK is sent.