diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 8d1a5a6258148f5b4ccdea454e1757839c8c5b04..799647927c4ca79a42294272518472641161d65b 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2444,7 +2444,7 @@ inline struct dl_bw *dl_bw_of(int i)
 	return &cpu_rq(i)->rd->dl_bw;
 }
 
-static inline int dl_bw_cpus(int i)
+inline int dl_bw_cpus(int i)
 {
 	struct root_domain *rd = cpu_rq(i)->rd;
 	int cpus = 0;
@@ -2462,7 +2462,7 @@ inline struct dl_bw *dl_bw_of(int i)
 	return &cpu_rq(i)->dl.dl_bw;
 }
 
-static inline int dl_bw_cpus(int i)
+inline int dl_bw_cpus(int i)
 {
 	return 1;
 }
@@ -2500,8 +2500,8 @@ static int dl_overflow(struct task_struct *p, int policy,
 	if (dl_policy(policy) && !task_has_dl_policy(p) &&
 	    !__dl_overflow(dl_b, cpus, 0, new_bw)) {
 		if (hrtimer_active(&p->dl.inactive_timer))
-			__dl_clear(dl_b, p->dl.dl_bw);
-		__dl_add(dl_b, new_bw);
+			__dl_clear(dl_b, p->dl.dl_bw, cpus);
+		__dl_add(dl_b, new_bw, cpus);
 		err = 0;
 	} else if (dl_policy(policy) && task_has_dl_policy(p) &&
 		   !__dl_overflow(dl_b, cpus, p->dl.dl_bw, new_bw)) {
@@ -2512,8 +2512,8 @@ static int dl_overflow(struct task_struct *p, int policy,
 		 * But this would require to set the task's "inactive
 		 * timer" when the task is not inactive.
 		 */
-		__dl_clear(dl_b, p->dl.dl_bw);
-		__dl_add(dl_b, new_bw);
+		__dl_clear(dl_b, p->dl.dl_bw, cpus);
+		__dl_add(dl_b, new_bw, cpus);
 		dl_change_utilization(p, new_bw);
 		err = 0;
 	} else if (!dl_policy(policy) && task_has_dl_policy(p)) {
@@ -5515,7 +5515,7 @@ int task_can_attach(struct task_struct *p,
 			 * We will free resources in the source root_domain
 			 * later on (see set_cpus_allowed_dl()).
 			 */
-			__dl_add(dl_b, p->dl.dl_bw);
+			__dl_add(dl_b, p->dl.dl_bw, cpus);
 		}
 		raw_spin_unlock_irqrestore(&dl_b->lock, flags);
 		rcu_read_unlock_sched();
@@ -6764,9 +6764,12 @@ void init_dl_rq_bw_ratio(struct dl_rq *dl_rq)
 {
 	if (global_rt_runtime() == RUNTIME_INF) {
 		dl_rq->bw_ratio = 1 << RATIO_SHIFT;
+		dl_rq->extra_bw = 1 << BW_SHIFT;
 	} else {
 		dl_rq->bw_ratio = to_ratio(global_rt_runtime(),
 			  global_rt_period()) >> (BW_SHIFT - RATIO_SHIFT);
+		dl_rq->extra_bw = to_ratio(global_rt_period(),
+						    global_rt_runtime());
 	}
 }
 
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 7d2f057780602a26d2d6a95e4f9a0f36372a88df..e3b25dfb74f36a6ee62b6fa32dc5706e48db3799 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -209,7 +209,7 @@ static void task_non_contending(struct task_struct *p)
 			if (p->state == TASK_DEAD)
 				sub_rq_bw(p->dl.dl_bw, &rq->dl);
 			raw_spin_lock(&dl_b->lock);
-			__dl_clear(dl_b, p->dl.dl_bw);
+			__dl_clear(dl_b, p->dl.dl_bw, dl_bw_cpus(task_cpu(p)));
 			__dl_clear_params(p);
 			raw_spin_unlock(&dl_b->lock);
 		}
@@ -955,28 +955,40 @@ extern bool sched_rt_bandwidth_account(struct rt_rq *rt_rq);
 /*
  * This function implements the GRUB accounting rule:
  * according to the GRUB reclaiming algorithm, the runtime is
- * not decreased as "dq = -dt", but as "dq = -max{u, (1 - Uinact)} dt",
- * where u is the utilization of the task and Uinact is the
- * (per-runqueue) inactive utilization, computed as the difference
- * between the "total runqueue utilization" and the runqueue
- * active utilization.
+ * not decreased as "dq = -dt", but as
+ * "dq = -max{u / Umax, (1 - Uinact - Uextra)} dt",
+ * where u is the utilization of the task, Umax is the maximum reclaimable
+ * utilization, Uinact is the (per-runqueue) inactive utilization, computed
+ * as the difference between the "total runqueue utilization" and the
+ * runqueue active utilization, and Uextra is the (per runqueue) extra
+ * reclaimable utilization.
  * Since rq->dl.running_bw and rq->dl.this_bw contain utilizations
- * multiplied by 2^BW_SHIFT, the result has to be shifted right by BW_SHIFT.
+ * multiplied by 2^BW_SHIFT, the result has to be shifted right by
+ * BW_SHIFT.
+ * Since rq->dl.bw_ratio contains 1 / Umax multipled by 2^RATIO_SHIFT,
+ * dl_bw is multiped by rq->dl.bw_ratio and shifted right by RATIO_SHIFT.
+ * Since delta is a 64 bit variable, to have an overflow its value
+ * should be larger than 2^(64 - 20 - 8), which is more than 64 seconds.
+ * So, overflow is not an issue here.
  */
 u64 grub_reclaim(u64 delta, struct rq *rq, struct sched_dl_entity *dl_se)
 {
 	u64 u_inact = rq->dl.this_bw - rq->dl.running_bw; /* Utot - Uact */
 	u64 u_act;
+	u64 u_act_min = (dl_se->dl_bw * rq->dl.bw_ratio) >> RATIO_SHIFT;
 
 	/*
-	 * Instead of computing max{u, (1 - u_inact)}, we compare
-	 * u_inact with 1 - u, because u_inact can be larger than 1
-	 * (so, 1 - u_inact would be negative leading to wrong results)
+	 * Instead of computing max{u * bw_ratio, (1 - u_inact - u_extra)},
+	 * we compare u_inact + rq->dl.extra_bw with
+	 * 1 - (u * rq->dl.bw_ratio >> RATIO_SHIFT), because
+	 * u_inact + rq->dl.extra_bw can be larger than
+	 * 1 * (so, 1 - u_inact - rq->dl.extra_bw would be negative
+	 * leading to wrong results)
 	 */
-	if (u_inact > BW_UNIT - dl_se->dl_bw)
-		u_act = dl_se->dl_bw;
+	if (u_inact + rq->dl.extra_bw > BW_UNIT - u_act_min)
+		u_act = u_act_min;
 	else
-		u_act = BW_UNIT - u_inact;
+		u_act = BW_UNIT - u_inact - rq->dl.extra_bw;
 
 	return (delta * u_act) >> BW_SHIFT;
 }
@@ -1085,7 +1097,7 @@ static enum hrtimer_restart inactive_task_timer(struct hrtimer *timer)
 		}
 
 		raw_spin_lock(&dl_b->lock);
-		__dl_clear(dl_b, p->dl.dl_bw);
+		__dl_clear(dl_b, p->dl.dl_bw, dl_bw_cpus(task_cpu(p)));
 		raw_spin_unlock(&dl_b->lock);
 		__dl_clear_params(p);
 
@@ -2054,7 +2066,7 @@ static void set_cpus_allowed_dl(struct task_struct *p,
 		 * until we complete the update.
 		 */
 		raw_spin_lock(&src_dl_b->lock);
-		__dl_clear(src_dl_b, p->dl.dl_bw);
+		__dl_clear(src_dl_b, p->dl.dl_bw, dl_bw_cpus(task_cpu(p)));
 		raw_spin_unlock(&src_dl_b->lock);
 	}
 
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index b7321dac03c11cf5c3e7fbdda553fd99c5a21d85..f1e400c6403cf9106618210cc63ddd44dae66314 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -219,22 +219,27 @@ static inline int dl_bandwidth_enabled(void)
 }
 
 extern struct dl_bw *dl_bw_of(int i);
+extern int dl_bw_cpus(int i);
 
 struct dl_bw {
 	raw_spinlock_t lock;
 	u64 bw, total_bw;
 };
 
+static inline void __dl_update(struct dl_bw *dl_b, s64 bw);
+
 static inline
-void __dl_clear(struct dl_bw *dl_b, u64 tsk_bw)
+void __dl_clear(struct dl_bw *dl_b, u64 tsk_bw, int cpus)
 {
 	dl_b->total_bw -= tsk_bw;
+	__dl_update(dl_b, (s32)tsk_bw / cpus);
 }
 
 static inline
-void __dl_add(struct dl_bw *dl_b, u64 tsk_bw)
+void __dl_add(struct dl_bw *dl_b, u64 tsk_bw, int cpus)
 {
 	dl_b->total_bw += tsk_bw;
+	__dl_update(dl_b, -((s32)tsk_bw / cpus));
 }
 
 static inline
@@ -576,6 +581,7 @@ struct dl_rq {
 	 * runqueue (inactive utilization = this_bw - running_bw).
 	 */
 	u64 this_bw;
+	u64 extra_bw;
 
 	/*
 	 * Inverse of the fraction of CPU utilization that can be reclaimed
@@ -1958,6 +1964,33 @@ extern void nohz_balance_exit_idle(unsigned int cpu);
 static inline void nohz_balance_exit_idle(unsigned int cpu) { }
 #endif
 
+
+#ifdef CONFIG_SMP
+static inline
+void __dl_update(struct dl_bw *dl_b, s64 bw)
+{
+	struct root_domain *rd = container_of(dl_b, struct root_domain, dl_bw);
+	int i;
+
+	RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held(),
+			 "sched RCU must be held");
+	for_each_cpu_and(i, rd->span, cpu_active_mask) {
+		struct rq *rq = cpu_rq(i);
+
+		rq->dl.extra_bw += bw;
+	}
+}
+#else
+static inline
+void __dl_update(struct dl_bw *dl_b, s64 bw)
+{
+	struct dl_rq *dl = container_of(dl_b, struct dl_rq, dl_bw);
+
+	dl->extra_bw += bw;
+}
+#endif
+
+
 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
 struct irqtime {
 	u64			total;