cvs commit: src/sys/dev/sio sio.c

[Bruce Evans]

bde         2003/09/15 06:49:18 PDT

  FreeBSD src repository

  Modified files:
    sys/dev/sio          sio.c 
  Log:
  Quick fix for a pessimization in rev.1.194.  An extra i/o instruction
  was added to the fast path to support the COM_IIR_RXRDYBUG() case even
  when that case is not configured.  This increased the relative overhead
  of sio input by almost 25% in the worst case and by 2-3% in the usual
  case (usually only about 0.2% absolute per port at 115200 bps).  The
  quick fix is to significantly pessimize only the COM_IIR_RXRDYBUG()
  case.
  
  Revision  Changes    Path
  1.405     +7 -2      src/sys/dev/sio/sio.c