cvs commit: src/sys/kern uipc_socket2.c uipc_usrreq.c src/sys/netinet ip_divert.c ip_mroute.c raw_ip.c tcp_input.c udp_usrreq.c

[Robert Watson]

rwatson     2004-06-26 19:10:39 UTC

  FreeBSD src repository

  Modified files:
    sys/kern             uipc_socket2.c uipc_usrreq.c 
    sys/netinet          ip_divert.c ip_mroute.c raw_ip.c 
                         tcp_input.c udp_usrreq.c 
  Log:
  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.
  
  Revision  Changes    Path
  1.136     +5 -8      src/sys/kern/uipc_socket2.c
  1.131     +3 -6      src/sys/kern/uipc_usrreq.c
  1.93      +6 -4      src/sys/netinet/ip_divert.c
  1.102     +5 -2      src/sys/netinet/ip_mroute.c
  1.135     +7 -3      src/sys/netinet/raw_ip.c
  1.248     +13 -8     src/sys/netinet/tcp_input.c
  1.156     +7 -2      src/sys/netinet/udp_usrreq.c