Comment # 3 on bug 1131437 from Jan Kara

So the first pair of runs didn't reproduce the issue. Results from
compare_kernels.sh:

Amean      1        24.35 (   0.00%)       25.89 (  -6.36%)
Amean      2        34.53 (   0.00%)       31.78 (   7.96%)
Amean      4        37.27 (   0.00%)       40.00 (  -7.32%)
Amean      8        48.15 (   0.00%)       48.73 (  -1.20%)
Amean      16       69.70 (   0.00%)       70.78 (  -1.54%)
Amean      32      130.43 (   0.00%)      130.74 (  -0.24%)
Amean      64      505.36 (   0.00%)      522.22 (  -3.34%)
Stddev     1         5.21 (   0.00%)        6.77 ( -29.92%)
Stddev     2         7.50 (   0.00%)        8.29 ( -10.58%)
Stddev     4         6.30 (   0.00%)        6.36 (  -0.85%)
Stddev     8         8.43 (   0.00%)        8.88 (  -5.32%)
Stddev     16       16.71 (   0.00%)       16.86 (  -0.94%)
Stddev     32       40.14 (   0.00%)       41.19 (  -2.60%)
Stddev     64      160.02 (   0.00%)      160.91 (  -0.56%)

So it really looks more related to the fact which also Giovanni noticed that
dbench4 results became more noisy recently... I'll see if I can nail that down.