[PATCH 0/3] cgroup: block device i/o bandwidth controller (v2)

[Andrea Righi <righi.andrea@gmail.com>]

The goal of the i/o bandwidth controller is to improve i/o performance
predictability and provide better QoS for different cgroups sharing the same
block devices.

Respect to other priority/weight-based solutions the approach used by this
controller is to explicitly choke applications' requests that directly (or
indirectly) generate i/o activity in the system.

The direct bandwidth limiting method has the advantage of improving the
performance predictability at the cost of reducing, in general, the overall
performance of the system (in terms of throughput).

Detailed informations about design, its goal and usage are described in the
documentation.

Tested against latest git (2.6.26-rc5).

The all-in-one patch can be found at:
http://download.systemimager.org/~arighi/linux/patches/io-throttle/

Previous version and test report can be found here:
http://lkml.org/lkml/2008/5/24/97

Changelog since v1:
* support multiple per-block device i/o limiting rules
* minor optimizations in cgroup_io_account()
* updated the documentation and fixed some typos (thanks to Randy Dunlap for
  reviewing)

-Andrea