Budget Fair Queueing I/O Scheduler
==================================

This patchset introduces BFQ into the Linux kernel; the overall
diffstat is the following:

 block/Kconfig.iosched         |   25 +
 block/Makefile                |    1 +
 block/bfq-cgroup.c            |  743 +++++++++++++++
 block/bfq-ioc.c               |  375 ++++++++
 block/bfq-iosched.c           | 2010 +++++++++++++++++++++++++++++++++++++++++
 block/bfq-sched.c             |  950 +++++++++++++++++++
 block/bfq.h                   |  514 +++++++++++
 block/blk-ioc.c               |   27 +-
 block/cfq-iosched.c           |   10 +-
 fs/ioprio.c                   |    9 +-
 include/linux/cgroup_subsys.h |    6 +
 include/linux/iocontext.h     |   18 +-
 12 files changed, 4669 insertions(+), 19 deletions(-)

For further information please refer to the patches themselves or to:
    http://algo.ing.unimo.it/people/paolo/disk_sched/
    http://feanor.sssup.it/~fabio/linux/bfq/


ChangeLog
=========

v3 - Address the issues pointed out during the first review:
     . use a bitmap to signal ioprio changes to I/O schedulers;
     . introduce a timeout to limit the huge delays that could happen
       with seeky traffic;
     . introduce hierarchical scheduling.

v2 - Fix a wrong assertion on idle queues (they can become an ->active_queue),
     and clean up some leftover from CFQ code import.  Also use a different
     ioprio_changed ioc field for bfq and fix the memory barriers used to
     handle it.

v1 - Backport the rcu-safe cic freeing from mainline CFQ.

v0 - Original version.