[PATCH] empty result

[PATCH] empty result

1. The job file looks like this:
---------runtime------------
[global]
directory=./temp
nrfiles=1
rw=randread
size=32k
thread
[runtime]
description="Too tiny a mission using less than 1sec."
----------------------------

Most of the time,it seems like no io has been performed:
----------------------------
nonggia@nonggia-desktop:~/fio$ fio runtime
runtime: (g=0): rw=randread, bs=4K-4K/4K-4K, ioengine=sync, iodepth=1
Starting 1 thread

runtime: (groupid=0, jobs=1): err= 0: pid=7155
  Description  : ["Too tiny a mission using less than 1sec."]
  cpu          : usr=0.00%, sys=0.00%, ctx=1
  IO depths    : 1=100.0%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 32=0.0%,
>=64=0.0%
     issued r/w: total=8/0, short=0/0
     lat (usec): 100=87.50%, 250=12.50%

Run status group 0 (all jobs):

Disk stats (read/write):
  sda: ios=8/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00%
nonggia@nonggia-desktop:~/fio$
----------------------------

2. Reason for the problem:
It is so tiny a job that it may cost less than one second to finish.And
the runtime is rounded down to 0.Just like the io never happened.
We agree that the problem is really trifle, but for testing purpose, we
think it maybe while the fixing.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>