sendfile/results

   1 5000 sleep
   2 send (B/MB)                     receive (B/MB)                  time (s)
   3 ------------------------------------------------------------
   4 1048576/1                       1048576/1                               1
   5 33554432/32                     25030616/24                             24
   6 67108864/64                     49692348/48                             44
   7 134217728/128           89076884/85                             89
   8 268435456/256           125071216/120                   164
   9
  10
  11 send (B/MB)                     receive (B/KB)                  time (s)
  12 ------------------------------------------------------------
  13 1048576/1                       139332/137                              1
  14 33554432/32                     344232/337                              6
  15 67108864/64                     368820/361                              8
  16 134217728/128           434388/425                              19
  17 268435456/256           1901472/1946                    53