2 files changed, 43 insertions, 0 deletions

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 28cabed85387..ed2ab474ec93 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5363,6 +5363,10 @@ static int wake_wide(struct task_struct *p)
  *
  * wake_affine_idle() - only considers 'now', it check if the waking CPU is (or
  *                      will be) idle.
+ *
+ * wake_affine_weight() - considers the weight to reflect the average
+ *                        scheduling latency of the CPUs. This seems to work
+ *                        for the overloaded case.
  */
 
 static bool
@@ -5378,6 +5382,40 @@ wake_affine_idle(struct sched_domain *sd, struct task_struct *p,
         return false;
 }
 
+static bool
+wake_affine_weight(struct sched_domain *sd, struct task_struct *p,
+                   int this_cpu, int prev_cpu, int sync)
+{
+        s64 this_eff_load, prev_eff_load;
+        unsigned long task_load;
+
+        this_eff_load = target_load(this_cpu, sd->wake_idx);
+        prev_eff_load = source_load(prev_cpu, sd->wake_idx);
+
+        if (sync) {
+                unsigned long current_load = task_h_load(current);
+
+                if (current_load > this_eff_load)
+                        return true;
+
+                this_eff_load -= current_load;
+        }
+
+        task_load = task_h_load(p);
+
+        this_eff_load += task_load;
+        if (sched_feat(WA_BIAS))
+                this_eff_load *= 100;
+        this_eff_load *= capacity_of(prev_cpu);
+
+        prev_eff_load -= task_load;
+        if (sched_feat(WA_BIAS))
+                prev_eff_load *= 100 + (sd->imbalance_pct - 100) / 2;
+        prev_eff_load *= capacity_of(this_cpu);
+
+        return this_eff_load <= prev_eff_load;
+}
+
 static int wake_affine(struct sched_domain *sd, struct task_struct *p,
                        int prev_cpu, int sync)
 {
@@ -5387,6 +5425,9 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p,
         if (sched_feat(WA_IDLE) && !affine)
                 affine = wake_affine_idle(sd, p, this_cpu, prev_cpu, sync);
 
+        if (sched_feat(WA_WEIGHT) && !affine)
+                affine = wake_affine_weight(sd, p, this_cpu, prev_cpu, sync);
+
         schedstat_inc(p->se.statistics.nr_wakeups_affine_attempts);
         if (affine) {
                 schedstat_inc(sd->ttwu_move_affine);
diff --git a/kernel/sched/features.h b/kernel/sched/features.h
index 0a519f8c224d..319ed0e8a347 100644
--- a/kernel/sched/features.h
+++ b/kernel/sched/features.h
@@ -82,3 +82,5 @@ SCHED_FEAT(LB_MIN, false)
 SCHED_FEAT(ATTACH_AGE_LOAD, true)
 
 SCHED_FEAT(WA_IDLE, true)
+SCHED_FEAT(WA_WEIGHT, true)
+SCHED_FEAT(WA_BIAS, true)