svn commit: r306661 - in stable/11/sys/dev/cxgbe: . tom

[Slawa Olhovchenkov]

On Mon, Oct 03, 2016 at 11:15:44PM +0000, John Baldwin wrote:

> Author: jhb
> Date: Mon Oct  3 23:15:44 2016
> New Revision: 306661
> URL: https://svnweb.freebsd.org/changeset/base/306661
> 
> Log:
>   MFC 303405: Add support for zero-copy aio_write() on TOE sockets.
>   
>   AIO write requests for a TOE socket on a Chelsio T4+ adapter can now
>   DMA directly from the user-supplied buffer.  This is implemented by
>   wiring the pages backing the user-supplied buffer and queueing special
>   mbufs backed by raw VM pages to the socket buffer.  The TOE code
>   recognizes these special mbufs and builds a sglist from the VM page
>   array associated with the mbuf when queueing a work request to the TOE.
>   
>   Because these mbufs do not have an associated virtual address, m_data
>   is not valid.  Thus, the AIO handler does not invoke sosend() directly
>   for these mbufs but instead inlines portions of sosend_generic() and
>   tcp_usr_send().
>   
>   An aiotx_buffer structure is used to describe the user buffer (e.g.
>   it holds the array of VM pages and a reference to the AIO job).  The
>   special mbufs reference this structure via m_ext.  Note that a single
>   job might be split across multiple mbufs (e.g. if it is larger than
>   the socket buffer size).  The 'ext_arg2' member of each mbuf gives an
>   offset relative to the backing aiotx_buffer.  The AIO job associated
>   with an aiotx_buffer structure is completed when the last reference to
>   the structure is released.
>   
>   Zero-copy aio_write()'s for connections associated with a given
>   adapter can be enabled/disabled at runtime via the
>   'dev.t[45]nex.N.toe.tx_zcopy' sysctl.
>   
>   Sponsored by:	Chelsio Communications

Do you have any public available application patches for support this?
May be nginx?