1 files changed, 34 insertions, 6 deletions

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 28db7ce5c3a6..b798fe7ff7cd 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6231,11 +6231,21 @@ static unsigned long cpu_util_next(int cpu, struct task_struct *p, int dst_cpu)
 static long
 compute_energy(struct task_struct *p, int dst_cpu, struct perf_domain *pd)
 {
-	long util, max_util, sum_util, energy = 0;
+	unsigned int max_util, util_cfs, cpu_util, cpu_cap;
+	unsigned long sum_util, energy = 0;
+	struct task_struct *tsk;
 	int cpu;
 
 	for (; pd; pd = pd->next) {
+		struct cpumask *pd_mask = perf_domain_span(pd);
+
+		/*
+		 * The energy model mandates all the CPUs of a performance
+		 * domain have the same capacity.
+		 */
+		cpu_cap = arch_scale_cpu_capacity(cpumask_first(pd_mask));
 		max_util = sum_util = 0;
+
 		/*
 		 * The capacity state of CPUs of the current rd can be driven by
 		 * CPUs of another rd if they belong to the same performance
@@ -6246,11 +6256,29 @@ compute_energy(struct task_struct *p, int dst_cpu, struct perf_domain *pd)
 		 * it will not appear in its pd list and will not be accounted
 		 * by compute_energy().
 		 */
-		for_each_cpu_and(cpu, perf_domain_span(pd), cpu_online_mask) {
-			util = cpu_util_next(cpu, p, dst_cpu);
-			util = schedutil_energy_util(cpu, util);
-			max_util = max(util, max_util);
-			sum_util += util;
+		for_each_cpu_and(cpu, pd_mask, cpu_online_mask) {
+			util_cfs = cpu_util_next(cpu, p, dst_cpu);
+
+			/*
+			 * Busy time computation: utilization clamping is not
+			 * required since the ratio (sum_util / cpu_capacity)
+			 * is already enough to scale the EM reported power
+			 * consumption at the (eventually clamped) cpu_capacity.
+			 */
+			sum_util += schedutil_cpu_util(cpu, util_cfs, cpu_cap,
+						       ENERGY_UTIL, NULL);
+
+			/*
+			 * Performance domain frequency: utilization clamping
+			 * must be considered since it affects the selection
+			 * of the performance domain frequency.
+			 * NOTE: in case RT tasks are running, by default the
+			 * FREQUENCY_UTIL's utilization can be max OPP.
+			 */
+			tsk = cpu == dst_cpu ? p : NULL;
+			cpu_util = schedutil_cpu_util(cpu, util_cfs, cpu_cap,
+						      FREQUENCY_UTIL, tsk);
+			max_util = max(max_util, cpu_util);
 		}
 
 		energy += em_pd_energy(pd->em_pd, max_util, sum_util);