andrea@laser:/mnt > dbench 40
40 clients started
..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................+..........................................................................................................................+..................+.....................................+...........................................................................................+...........................................+..+.......................................++............................................+................+............+..................++++++++++++++++++++++++++++****************************************
Throughput 9.40112 MB/sec (NB.7514 MB/sec  94.0112 MBit/sec)
andrea@laser:/mnt > dbench 40
40 clients started
.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................+.....................................+...................................................+...............................................................................+...+...............................................................................+.........................+.....................................+...............+................................................................................+.++++++++++++++++++++++++++++++****************************************
Throughput 9.56469 MB/sec (NB.9559 MB/sec  95.6469 MBit/sec)
andrea@laser:/mnt > 

After I apply my vm patch dbench constantly says:

andrea@laser:/mnt > for i in 1 2 3 4 ; do dbench 40; done
40 clients started
.......................................................................................................................................................................................................................................................................................................++.+..+...+...............................+..+..............................................................................................................................................................+.........................+.................................................................................+..........................................+.......................................................................................+...............+.+..+..........................................................................................................+.................+.................+.......................+...........................+..........................+...................................+....+.+.+........................................+................................+.+...................................................................................................................................+........................................................................+...........................+................................................................+.......................+...........................+.............................................................++++++****************************************
Throughput 20.353 MB/sec (NB%.4412 MB/sec  203.53 MBit/sec)
40 clients started
................................................................................................................+.................................................+..............+............................................+.....................................................................................................................................................+........................................+....+................+.+..........................................++.......................................+...............................+...................................................+............................................................................+.........+.....................................................................+..............................................................................................................................................................................+............+................................+..............................................................+...............+.......................................................+...+++...................................+.................................+............+..............................+...................................................++...................................................+...............................................................................................................+.......+...+....................................+......+...+...+****************************************
Throughput 20.9269 MB/sec (NB&.1586 MB/sec  209.269 MBit/sec)
40 clients started
..........................................................................................................................................+.............................+..........+..............................................................................+............+...............................................+...................................................................+.......................+.........................................................................................................................++......+.........................................................................+.........+....+.......+...................................................+....+.............................................+....................................................+..........................................................+................+.......................................................................................................................................................+.........+...............................................................+........................+.........................................................................+.....................................................................................................................................................................+.......+..+..........................+............................+................+................+.....+......+..........+...............+........+.....+.+****************************************
Throughput 21.0787 MB/sec (NB&.3483 MB/sec  210.787 MBit/sec)
40 clients started
.................................................................................................................................................................+......................+.+...................................+.......................................+...............................+........................................................................................+.........................................................+................................+...................................................................................................................++................+.................................+........................+........................+....................+.......................++..........................................................+......+.........................................+......................................................+...............................+...............................................................................+...................................................+......................................................................................................................................................................................................+.....................+......+...............................+................................................+..........................................+.......+......................................+..............................+...+.+.+............+.++****************************************
Throughput 21.6167 MB/sec (NB'.0208 MB/sec  216.167 MBit/sec)
andrea@laser:/mnt >