patch for test (Was: tcp_output starving -- is due to mbuf get delay?)

[Jin Guojun [NCS]]

I have modified the sockbuf and mbuf operation to double the throughput over
high bandwidth delay product path.

The patch is available at:
    http://www-didc.lbl.gov/~jin/network/lion/content.html#FreeBSD_Patches

The current modification is for tcp transmission only.

I have adapted some code of uipc_socket2.c from Sam Leffler
    http://www.freebsd.org/~sam/thorpe-stable.patch

for tcp receiver, but it has not been tested yet, so the tcp_input.p is empty.

I ignored all record chain (m_nextpkt) related code. The details is explained at

    http://www-didc.lbl.gov/~jin/network/lion/content.html#BSDMbuf

Once the tcp_input code is tested, I will submit the patch to bugs at freebsd.org.
I may submit the patch regardless if tcp_input code works or not, because the
tcp
sender (server) is more important in high-speed network than the receiver
(client).

It is appreciated if any one can verify the patch and provide feedback.

--
------------ Jin Guojun ----------- v --- j_guojun at lbl.gov ---
Distributed Systems Department          http://www.itg.lbl.gov/~jin
M/S 50B-2239                            Ph#:(510) 486-7531 Fax: 486-6363
Lawrence Berkeley National Laboratory,  Berkeley, CA 94720