o This is core of the io scheduler implemented at elevator layer. This is a mix
of cpu CFS scheduler and CFQ IO scheduler. Some of the bits from CFS have
to be derived so that we can support hierarchical scheduling. Without
cgroups or with-in group, we should essentially get same behavior as CFQ.
o This patch only shows non-hierarchical bits. Hierarhical code comes in later
patches.
o This code is the building base of introducing fair queuing logic in common
elevator layer so that it can be used by all the four IO schedulers.
Signed-off-by: Fabio Checconi <fabio gandalf sssup it>
Signed-off-by: Paolo Valente <paolo valente unimore it>
Signed-off-by: Nauman Rafique <nauman google com>
Signed-off-by: Vivek Goyal <vgoyal redhat com>