Kernel processes

  PID TTY STAT TIME COMMAND
    1  ?  S    0:03 init 
    2  ?  SW   0:00 (kflushd)
    3  ?  SW<  0:00 (kswapd)
  403  ?  S    0:00 update (bdflush)

These processes are part of the kernel, or are an integral part of the system and should be left alone.