cvs commit: src/sys/kern uipc_syscalls.c

[Robert Watson]

rwatson     2004-10-24 23:45:01 UTC

  FreeBSD src repository

  Modified files:
    sys/kern             uipc_syscalls.c 
  Log:
  Move from using the socket reference count to the file reference
  count to prevent sockets from being garbage collected during
  socket-specific system calls.  This is the same approach used in
  most VFS-specific system calls, as well as generic file descriptor
  system calls such as read() and write().
  
  To do this, add a utility function getsock(), which is logically
  identical to getvnode() used for the same purpose in VFS.  Unlike
  fgetsock(), it returns with the file reference count elevated, but
  no bump of the socket reference count.  Replace matching calls to
  fputsock() with fdrop().
  
  This change is made to all socket system calls other than
  sendfile() and accept(), but the approach should be applicable to
  those system calls also.
  
  This shaves about four mutex operations off of each of these
  system calls, including send() and recv() variants, adding about
  1% to pps on minimal UDP packets for UP using netblast, and 4% on
  SMP.
  
  Reviewed by:    pjd
  
  Revision  Changes    Path
  1.204     +87 -23    src/sys/kern/uipc_syscalls.c