sched: cpufreq: HMP load reporting changes

Since HMP uses WALT, ensure that load is reported just once per window,
with the exception of intercluster migrations. Further, try to report load
whenever WALT stats are updated.

Change-Id: I6539f8c916f6f271cf26f03249de7f953d5b12c2
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>

include/linux/sched.h

@@ -3725,6 +3725,7 @@ static inline unsigned long rlimit_max(unsigned int limit)
 #define SCHED_CPUFREQ_RT        (1U << 0)
 #define SCHED_CPUFREQ_DL        (1U << 1)
 #define SCHED_CPUFREQ_IOWAIT    (1U << 2)
+#define SCHED_CPUFREQ_INTERCLUSTER_MIG (1U << 3)
 
 #ifdef CONFIG_CPU_FREQ
 struct update_util_data {

kernel/sched/core.c

@@ -2132,6 +2132,7 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags,
 	wallclock = sched_ktime_clock();
 	update_task_ravg(rq->curr, rq, TASK_UPDATE, wallclock, 0);
 	update_task_ravg(p, rq, TASK_WAKE, wallclock, 0);
+	cpufreq_update_util(rq, 0);
 	raw_spin_unlock(&rq->lock);
 
 	rcu_read_lock();
@@ -2225,6 +2226,7 @@ static void try_to_wake_up_local(struct task_struct *p)
 
 		update_task_ravg(rq->curr, rq, TASK_UPDATE, wallclock, 0);
 		update_task_ravg(p, rq, TASK_WAKE, wallclock, 0);
+		cpufreq_update_util(rq, 0);
 		ttwu_activate(rq, p, ENQUEUE_WAKEUP);
 		note_task_waking(p, wallclock);
 	}
@@ -3196,6 +3198,8 @@ void scheduler_tick(void)
 	calc_global_load_tick(rq);
 	wallclock = sched_ktime_clock();
 	update_task_ravg(rq->curr, rq, TASK_UPDATE, wallclock, 0);
+
+	cpufreq_update_util(rq, 0);
 	early_notif = early_detection_notify(rq, wallclock);
 	raw_spin_unlock(&rq->lock);
 
@@ -3564,6 +3568,7 @@ static void __sched notrace __schedule(bool preempt)
 	if (likely(prev != next)) {
 		update_task_ravg(prev, rq, PUT_PREV_TASK, wallclock, 0);
 		update_task_ravg(next, rq, PICK_NEXT_TASK, wallclock, 0);
+		cpufreq_update_util(rq, 0);
 		if (!is_idle_task(prev) && !prev->on_rq)
 			update_avg_burst(prev);
 
@@ -3582,6 +3587,7 @@ static void __sched notrace __schedule(bool preempt)
 		cpu = cpu_of(rq);
 	} else {
 		update_task_ravg(prev, rq, TASK_UPDATE, wallclock, 0);
+		cpufreq_update_util(rq, 0);
 		lockdep_unpin_lock(&rq->lock);
 		raw_spin_unlock_irq(&rq->lock);
 	}

kernel/sched/hmp.c

@@ -3649,6 +3649,11 @@ void fixup_busy_time(struct task_struct *p, int new_cpu)
 
 	migrate_top_tasks(p, src_rq, dest_rq);
 
+	if (!same_freq_domain(new_cpu, task_cpu(p))) {
+		cpufreq_update_util(dest_rq, SCHED_CPUFREQ_INTERCLUSTER_MIG);
+		cpufreq_update_util(src_rq, SCHED_CPUFREQ_INTERCLUSTER_MIG);
+	}
+
 	if (p == src_rq->ed_task) {
 		src_rq->ed_task = NULL;
 		if (!dest_rq->ed_task)

kernel/sched/sched.h

@@ -440,6 +440,7 @@ struct cpu_cycle {
 #define for_each_sched_cluster(cluster) \
 	list_for_each_entry_rcu(cluster, &cluster_head, list)
 
+extern unsigned int sched_disable_window_stats;
 #endif /* CONFIG_SCHED_HMP */
 
 /* CFS-related fields in a runqueue */
@@ -792,6 +793,7 @@ struct rq {
 
 	int cstate, wakeup_latency, wakeup_energy;
 	u64 window_start;
+	u64 load_reported_window;
 	unsigned long hmp_flags;
 
 	u64 cur_irqload;
@@ -2852,6 +2854,18 @@ static inline void cpufreq_update_util(struct rq *rq, unsigned int flags)
 {
         struct update_util_data *data;
 
+#ifdef CONFIG_SCHED_HMP
+	/*
+	 * Skip if we've already reported, but not if this is an inter-cluster
+	 * migration
+	 */
+	if (!sched_disable_window_stats &&
+		(rq->load_reported_window == rq->window_start) &&
+		!(flags & SCHED_CPUFREQ_INTERCLUSTER_MIG))
+		return;
+	rq->load_reported_window = rq->window_start;
+#endif
+
         data = rcu_dereference_sched(*this_cpu_ptr(&cpufreq_update_util_data));
         if (data)
                 data->func(data, rq_clock(rq), flags);