K 10
svn:author
V 7
rwatson
K 8
svn:date
V 27
2004-06-26T19:10:39.000000Z
K 7
svn:log
V 977
Reduce the number of unnecessary unlock-relocks on socket buffer mutexes
associated with performing a wakeup on the socket buffer:

- When performing an sbappend*() followed by a so[rw]wakeup(), explicitly
  acquire the socket buffer lock and use the _locked() variants of both
  calls.  Note that the _locked() sowakeup() versions unlock the mutex on
  return.  This is done in uipc_send(), divert_packet(), mroute
  socket_send(), raw_append(), tcp_reass(), tcp_input(), and udp_append().

- When the socket buffer lock is dropped before a sowakeup(), remove the
  explicit unlock and use the _locked() sowakeup() variant.  This is done
  in soisdisconnecting(), soisdisconnected() when setting the can't send/
  receive flags and dropping data, and in uipc_rcvd() which adjusting
  back-pressure on the sockets.

For UNIX domain sockets running mpsafe with a contention-intensive SMP
mysql benchmark, this results in a 1.6% query rate improvement due to
reduce mutex costs.

END