[patch v5 15/15] sched: lazy power balance

When active task number in sched domain waves around the power friendly scheduling creteria, scheduling will thresh between the power friendly balance and performance balance, bring unnecessary task migration. The typical benchmark is 'make -j x'. To remove such issue, introduce a u64

[patch v5 15/15] sched: lazy power balance

When active task number in sched domain waves around the power friendly scheduling creteria, scheduling will thresh between the power friendly balance and performance balance, bring unnecessary task migration. The typical benchmark is 'make -j x'. To remove such issue, introduce a u64