This is common fair queuing code in elevator layer. This is controlled by
config option CONFIG_ELV_FAIR_QUEUING. This patch initially only introduces
flat fair queuing support where there is only one group, "root group" and all
the tasks belong to root group.
This elevator layer changes are backward compatible. That means any ioscheduler
using old interfaces will continue to work.
This is essentially a lot of CFQ logic moved into common layer so that other
IO schedulers can make use of that in hierarhical scheduling setup.
Signed-off-by: Nauman Rafique <nauman@xxxxxxxxxx>
Signed-off-by: Fabio Checconi <fabio@xxxxxxxxxxxxxxxx>
Signed-off-by: Paolo Valente <paolo.valente@xxxxxxxxxx>
Signed-off-by: Aristeu Rozanski <aris@xxxxxxxxxx>
Signed-off-by: Gui Jianfeng <guijianfeng@xxxxxxxxxxxxxx>
Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx>