Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

DEBUG_FLAGS -g is default for GENERIC and its presence interferes with
disabling the sfxge.ko.symbols build for embedded systems.

Approved by: re (marius)
MFC after: 3 days

Remove zero-copy sockets code. It only worked for anonymous memory,
and the equivalent functionality is now provided by sendfile(2) over
posix shared memory filedescriptor.

Remove the cow member of struct vm_page, and rearrange the remaining
members. While there, make hold_count unsigned.

Requested and reviewed by: alc
Tested by: pho
Sponsored by: The FreeBSD Foundation
Approved by: re (delphij)

Add the sfxge(4) device driver, providing support for 10Gb Ethernet adapters
based on Solarflare SFC9000 family controllers. The driver supports jumbo
frames, transmit/receive checksum offload, TCP Segmentation Offload (TSO),
Large Receive Offload (LRO), VLAN checksum offload, VLAN TSO, and Receive Side
Scaling (RSS) using MSI-X interrupts.

This work was sponsored by Solarflare Communications, Inc.

My sincere thanks to Ben Hutchings for doing a lot of the hard work!

Sponsored by: Solarflare Communications, Inc.
MFC after: 3 weeks