IO scheduler based IO controller V10

[Mike Galbraith]

P.S.

On Mon, 2009-09-28 at 06:04 +0200, Mike Galbraith wrote:

> - = virgin tip v2.6.31-10215-ga3c9602
> + = with patchlet
>                                                             Avg
> dd pre         67.4     70.9     65.4     68.9     66.2     67.7-
>                65.9     68.5     69.8     65.2     65.8     67.0-     Avg
>                70.4     70.3     65.1     66.4     70.1     68.4-     67.7-
>                73.1     64.6     65.3     65.3     64.9     66.6+     65.6+     .968
>                63.8     67.9     65.2     65.1     64.4     65.2+
>                64.9     66.3     64.1     65.2     64.8     65.0+
> perf stat      8.66    16.29     9.65    14.88     9.45     11.7-
>               15.36     9.71    15.47    10.44    12.93     12.7-
>               10.55    15.11    10.22    15.35    10.32     12.3-     12.2-
>                9.87     7.53    10.62     7.51     9.95      9.0+      9.1+     .745
>                7.73    10.12     8.19    11.87     8.07      9.1+
>               11.04     7.62    10.14     8.13    10.23      9.4+
> dd post        63.4     60.5     66.7     64.5     67.3     64.4-
>                64.4     66.8     64.3     61.5     62.0     63.8-
>                63.8     64.9     66.2     65.6     66.9     65.4-     64.5-
>                60.9     63.4     60.2     63.4     65.5     62.6+     61.8+     .958
>                63.3     59.9     61.9     62.7     61.2     61.8+
>                60.1     63.7     59.5     61.5     60.6     61.0+

Deadline and noop fsc^W are less than wonderful choices for this load.

perf stat     12.82     7.19     8.49     5.76      9.32   anticipatory
              16.24   175.82   154.38   228.97    147.16   noop
              43.23    57.39    96.13   148.25    180.09   deadline
              28.65   167.40   195.95   183.69    178.61   deadline v2.6.27.35

	-Mike