sched: Consider max cost of idle balance per sched domain

Signed-off-by: Rob Beane <robbeane@gmail.com>

Conflicts:
	kernel/sched/core.c

Signed-off-by: Rob Beane <robbeane@gmail.com>
sched: document the difference between nr_running and h_nr_running

Date    Sun, 18 Aug 2013 16:25:22 +0800

Signed-off-by: Lei Wen <leiwen@marvell.com>

Signed-off-by: Paul Reioux <reioux@gmail.com>
Signed-off-by: Rob Beane <robbeane@gmail.com>