ANDROID: sched/fair: update_max_interval() active_mask dependant

Adding support in update_max_interval() for incomplete HP _cpu_down, where
cpu_active_mask != cpu_online_mask. This situation can happen in the event
of a partial _cpu_down. i.e. _cpu_down(target) where
target > CPUHP_AP_OFFLINE.

Bug: 161210528
Change-Id: Ia422057c65f16dc9aa8f6d272098b2308b00f0ac
Signed-off-by: Vincent Donnefort <vincent.donnefort@arm.com>

kernel/sched/core.c

@@ -6971,6 +6971,8 @@ int sched_cpu_activate(unsigned int cpu)
 	}
 	rq_unlock_irqrestore(rq, &rf);
 
+	update_max_interval();
+
 	return 0;
 }
 
@@ -7005,6 +7007,9 @@ int sched_cpu_deactivate(unsigned int cpu)
 		return ret;
 	}
 	sched_domains_numa_masks_clear(cpu);
+
+	update_max_interval();
+
 	return 0;
 }
 
@@ -7013,7 +7018,6 @@ static void sched_rq_cpu_starting(unsigned int cpu)
 	struct rq *rq = cpu_rq(cpu);
 
 	rq->calc_load_update = calc_load_update;
-	update_max_interval();
 }
 
 int sched_cpu_starting(unsigned int cpu)
@@ -7045,7 +7049,6 @@ int sched_cpu_dying(unsigned int cpu)
 	trace_android_rvh_sched_cpu_dying(cpu);
 
 	calc_load_migrate(rq);
-	update_max_interval();
 	nohz_balance_exit_idle(rq);
 	hrtick_clear(rq);
 	return 0;

kernel/sched/fair.c

@@ -10033,7 +10033,7 @@ static DEFINE_SPINLOCK(balancing);
  */
 void update_max_interval(void)
 {
-	max_load_balance_interval = HZ*num_online_cpus()/10;
+	max_load_balance_interval = HZ*num_active_cpus()/10;
 }
 
 /*