K 10
svn:author
V 7
rwatson
K 8
svn:date
V 27
2008-09-15T20:46:32.200635Z
K 7
svn:log
V 1440
Merge r180198, r180211, r180365, r182682 from head to stable/7:

  Add soreceive_dgram(9), an optimized socket receive function for use by
  datagram-only protocols, such as UDP.  This version removes use of
  sblock(), which is not required due to an inability to interlace data
  improperly with datagrams, as well as avoiding some of the larger loops
  and state management that don't apply on datagram sockets.

  This is experimental code, so hook it up only for UDPv4 for testing; if
  there are problems we may need to revise it or turn it off by default,
  but it offers *significant* performance improvements for threaded UDP
  applications such as BIND9, nsd, and memcached using UDP.

  Tested by:      kris, ps

  Update copyright date in light of soreceive_dgram(9).

  Use soreceive_dgram() and sosend_dgram() with UDPv6, as we do with UDPv4.

  Tested by:      ps

  Remove XXXRW in soreceive_dgram that proves unnecessary.

  Remove unused orig_resid variable in soreceive_dgram.

  Submitted by:   alfred

Note: in the MFC, we do enable sosend_dgram for UDPv6 by default (it was
already used for UDPv4), but use of soreceive_dgram for both UDPv4 and
UDPv6 is controlled by a new loader tunable,
net.inet.udp.soreceive_dgram_enabled as soreceive_dgram has less testing
exposure than sosend_dgram.  We may wish to change the default (and
eliminate the tunable) in 7.2.

MFC requested by:	gnn, kris, ps
Approved by:		re (kib)

END