netdev - Piggyback the final ACK of the three way TCP connection establishment with the data

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Date:	Wed, 21 Mar 2012 16:38:15 -0700
From:	Vincent Li <vincent.mc.li@...il.com>
To:	netdev@...r.kernel.org
Subject: Piggyback the final ACK of the three way TCP connection establishment
 with the data

Hi,

I happen to see this link
http://h20000.www2.hp.com/bc/docs/support/SupportManual/c02020743/c02020743.pdf
and

tcp_delay_final_twh_ack:
            Piggyback the final ACK of the three way TCP connection
            establishment with the data by delaying the final ack by
           10ms.

           0: Send the final ACK as soon as the SYN+ACK packet
               arrives from the remote host.

           1: Delay the sending of the final ACK by 10ms. If
               there is data available to be sent with in the
               next 10ms, piggyback the ACK for the SYN.
[0-1] Default: 1

It appears this feature is not available in kernel tcp implementation,
is it trivial to make a custom patch to make this feature available?
can someone give a hint on how to make a patch for this?

We had a situation that we want to make linux kernel tcp stack behave
this way so we can reproduce another issue at hand.

Thanks

Vincent
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