Proxy Execution: A generalized form of Priority Inheritance v6

index 77f01ac385f7..4f5b0710c0f1 100644
@@ -520,7 +520,7 @@ struct sched_statistics {
 	u64				block_max;
 	s64				sum_block_runtime;
 
-	u64				exec_max;
+	s64				exec_max;
 	u64				slice_max;
 
 	u64				nr_migrations_cold;

index 58b542bf2893..9522e6607754 100644
@@ -1299,9 +1299,8 @@ static void update_curr_dl(struct rq *rq)
 {
 	struct task_struct *curr = rq->curr;
 	struct sched_dl_entity *dl_se = &curr->dl;
-	u64 delta_exec, scaled_delta_exec;
+	s64 delta_exec, scaled_delta_exec;
 	int cpu = cpu_of(rq);
-	u64 now;
 
 	if (!dl_task(curr) || !on_dl_rq(dl_se))
 		return;

@@ -1314,21 +1313,15 @@ static void update_curr_dl(struct rq *rq)
 	 * natural solution, but the full ramifications of this
 	 * approach need further study.
 	 */
-	now = rq_clock_task(rq);
-	delta_exec = now - curr->se.exec_start;
-	if (unlikely((s64)delta_exec <= 0)) {
+	delta_exec = update_curr_common(rq);
+	if (unlikely(delta_exec <= 0)) {
 		if (unlikely(dl_se->dl_yielded))
 			goto throttle;
 		return;
 	}
 
-	schedstat_set(curr->stats.exec_max,
-		      max(curr->stats.exec_max, delta_exec));
-
 	trace_sched_stat_runtime(curr, delta_exec, 0);
 
-	update_current_exec_runtime(curr, now, delta_exec);
-
 	if (dl_entity_is_special(dl_se))
 		return;
 

74 lines not on this page · raw message

index 0597ba0f85ff..327ae4148aec 100644
@@ -1046,24 +1046,17 @@ static void update_curr_rt(struct rq *rq)
 {
 	struct task_struct *curr = rq->curr;
 	struct sched_rt_entity *rt_se = &curr->rt;
-	u64 delta_exec;
-	u64 now;
+	s64 delta_exec;
 
 	if (curr->sched_class != &rt_sched_class)
 		return;
 
-	now = rq_clock_task(rq);
-	delta_exec = now - curr->se.exec_start;
-	if (unlikely((s64)delta_exec <= 0))
+	delta_exec = update_curr_common(rq);
+	if (unlikely(delta_exec < 0))
 		return;
 
-	schedstat_set(curr->stats.exec_max,
-		      max(curr->stats.exec_max, delta_exec));
-
 	trace_sched_stat_runtime(curr, delta_exec, 0);
 
-	update_current_exec_runtime(curr, now, delta_exec);
-
 	if (!rt_bandwidth_enabled())
 		return;
 

index 04846272409c..1def5b7fa1df 100644
@@ -2228,6 +2228,8 @@ struct affinity_context {
 	unsigned int flags;
 };
 
+extern s64 update_curr_common(struct rq *rq);
+
 struct sched_class {
 
 #ifdef CONFIG_UCLAMP_TASK

@@ -3280,16 +3282,6 @@ extern int sched_dynamic_mode(const char *str);
 extern void sched_dynamic_update(int mode);
 #endif
 
-static inline void update_current_exec_runtime(struct task_struct *curr,
-						u64 now, u64 delta_exec)
-{
-	curr->se.sum_exec_runtime += delta_exec;
-	account_group_exec_runtime(curr, delta_exec);
-
-	curr->se.exec_start = now;
-	cgroup_account_cputime(curr, delta_exec);
-}
-
 #ifdef CONFIG_SCHED_MM_CID
 
 #define SCHED_MM_CID_PERIOD_NS	(100ULL * 1000000)	/* 100ms */

index 85590599b4d6..7595494ceb6d 100644
@@ -70,18 +70,7 @@ static void yield_task_stop(struct rq *rq)
 
 static void put_prev_task_stop(struct rq *rq, struct task_struct *prev)
 {
-	struct task_struct *curr = rq->curr;
-	u64 now, delta_exec;
-
-	now = rq_clock_task(rq);
-	delta_exec = now - curr->se.exec_start;
-	if (unlikely((s64)delta_exec < 0))
-		delta_exec = 0;
-
-	schedstat_set(curr->stats.exec_max,
-		      max(curr->stats.exec_max, delta_exec));
-
-	update_current_exec_runtime(curr, now, delta_exec);
+	update_curr_common(rq);
 }
 
 /*

index d973fe6041bf..4ada158eb7ca 100644
@@ -570,6 +570,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 		    struct lockdep_map *nest_lock, unsigned long ip,
 		    struct ww_acquire_ctx *ww_ctx, const bool use_ww_ctx)
 {
+	DEFINE_WAKE_Q(wake_q);
 	struct mutex_waiter waiter;
 	struct ww_mutex *ww;
 	int ret;

@@ -620,7 +621,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 	 */
 	if (__mutex_trylock(lock)) {
 		if (ww_ctx)
-			__ww_mutex_check_waiters(lock, ww_ctx);
+			__ww_mutex_check_waiters(lock, ww_ctx, &wake_q);
 
 		goto skip_wait;
 	}

@@ -640,7 +641,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 		 * Add in stamp order, waking up waiters that must kill
 		 * themselves.
 		 */
-		ret = __ww_mutex_add_waiter(&waiter, lock, ww_ctx);
+		ret = __ww_mutex_add_waiter(&waiter, lock, ww_ctx, &wake_q);
 		if (ret)
 			goto err_early_kill;
 	}

@@ -676,6 +677,11 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 		}
 
 		raw_spin_unlock(&lock->wait_lock);
+		/* Make sure we do wakeups before calling schedule */
+		if (!wake_q_empty(&wake_q)) {
+			wake_up_q(&wake_q);
+			wake_q_init(&wake_q);
+		}
 		schedule_preempt_disabled();
 
 		first = __mutex_waiter_is_first(lock, &waiter);

@@ -709,7 +715,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 		 */
 		if (!ww_ctx->is_wait_die &&
 		    !__mutex_waiter_is_first(lock, &waiter))
-			__ww_mutex_check_waiters(lock, ww_ctx);
+			__ww_mutex_check_waiters(lock, ww_ctx, &wake_q);
 	}
 
 	__mutex_remove_waiter(lock, &waiter);

@@ -725,6 +731,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 		ww_mutex_lock_acquired(ww, ww_ctx);
 
 	raw_spin_unlock(&lock->wait_lock);
+	wake_up_q(&wake_q);
 	preempt_enable();
 	return 0;
 

@@ -736,6 +743,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 	raw_spin_unlock(&lock->wait_lock);
 	debug_mutex_free_waiter(&waiter);
 	mutex_release(&lock->dep_map, ip);
+	wake_up_q(&wake_q);
 	preempt_enable();
 	return ret;
 }

@@ -929,6 +937,7 @@ static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigne
 		}
 	}
 
+	preempt_disable();
 	raw_spin_lock(&lock->wait_lock);
 	debug_mutex_unlock(lock);
 	if (!list_empty(&lock->wait_list)) {

@@ -947,8 +956,8 @@ static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigne
 		__mutex_handoff(lock, next);
 
 	raw_spin_unlock(&lock->wait_lock);
-
 	wake_up_q(&wake_q);
+	preempt_enable();
 }
 
 #ifndef CONFIG_DEBUG_LOCK_ALLOC

index 3ad2cc4823e5..7189c6631d90 100644
@@ -275,7 +275,7 @@ __ww_ctx_less(struct ww_acquire_ctx *a, struct ww_acquire_ctx *b)
  */
 static bool
 __ww_mutex_die(struct MUTEX *lock, struct MUTEX_WAITER *waiter,
-	       struct ww_acquire_ctx *ww_ctx)
+	       struct ww_acquire_ctx *ww_ctx, struct wake_q_head *wake_q)
 {
 	if (!ww_ctx->is_wait_die)
 		return false;

@@ -284,7 +284,7 @@ __ww_mutex_die(struct MUTEX *lock, struct MUTEX_WAITER *waiter,
 #ifndef WW_RT
 		debug_mutex_wake_waiter(lock, waiter);
 #endif
-		wake_up_process(waiter->task);
+		wake_q_add(wake_q, waiter->task);
 	}
 
 	return true;

@@ -299,7 +299,8 @@ __ww_mutex_die(struct MUTEX *lock, struct MUTEX_WAITER *waiter,
  */
 static bool __ww_mutex_wound(struct MUTEX *lock,
 			     struct ww_acquire_ctx *ww_ctx,
-			     struct ww_acquire_ctx *hold_ctx)
+			     struct ww_acquire_ctx *hold_ctx,
+			     struct wake_q_head *wake_q)
 {
 	struct task_struct *owner = __ww_mutex_owner(lock);
 

@@ -331,7 +332,7 @@ static bool __ww_mutex_wound(struct MUTEX *lock,
 		 * wakeup pending to re-read the wounded state.
 		 */
 		if (owner != current)
-			wake_up_process(owner);
+			wake_q_add(wake_q, owner);
 
 		return true;
 	}

@@ -352,7 +353,8 @@ static bool __ww_mutex_wound(struct MUTEX *lock,
  * The current task must not be on the wait list.
  */
 static void
-__ww_mutex_check_waiters(struct MUTEX *lock, struct ww_acquire_ctx *ww_ctx)
+__ww_mutex_check_waiters(struct MUTEX *lock, struct ww_acquire_ctx *ww_ctx,
+			 struct wake_q_head *wake_q)
 {
 	struct MUTEX_WAITER *cur;
 

@@ -364,8 +366,8 @@ __ww_mutex_check_waiters(struct MUTEX *lock, struct ww_acquire_ctx *ww_ctx)
 		if (!cur->ww_ctx)
 			continue;
 
-		if (__ww_mutex_die(lock, cur, ww_ctx) ||
-		    __ww_mutex_wound(lock, cur->ww_ctx, ww_ctx))
+		if (__ww_mutex_die(lock, cur, ww_ctx, wake_q) ||
+		    __ww_mutex_wound(lock, cur->ww_ctx, ww_ctx, wake_q))
 			break;
 	}
 }

@@ -377,6 +379,8 @@ __ww_mutex_check_waiters(struct MUTEX *lock, struct ww_acquire_ctx *ww_ctx)
 static __always_inline void
 ww_mutex_set_context_fastpath(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
 {
+	DEFINE_WAKE_Q(wake_q);
+
 	ww_mutex_lock_acquired(lock, ctx);
 
 	/*

@@ -405,8 +409,10 @@ ww_mutex_set_context_fastpath(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
 	 * die or wound us.
 	 */
 	lock_wait_lock(&lock->base);
-	__ww_mutex_check_waiters(&lock->base, ctx);
+	__ww_mutex_check_waiters(&lock->base, ctx, &wake_q);
 	unlock_wait_lock(&lock->base);
+
+	wake_up_q(&wake_q);
 }
 
 static __always_inline int

@@ -488,7 +494,8 @@ __ww_mutex_check_kill(struct MUTEX *lock, struct MUTEX_WAITER *waiter,
 static inline int
 __ww_mutex_add_waiter(struct MUTEX_WAITER *waiter,
 		      struct MUTEX *lock,
-		      struct ww_acquire_ctx *ww_ctx)
+		      struct ww_acquire_ctx *ww_ctx,
+		      struct wake_q_head *wake_q)
 {
 	struct MUTEX_WAITER *cur, *pos = NULL;
 	bool is_wait_die;

@@ -532,7 +539,7 @@ __ww_mutex_add_waiter(struct MUTEX_WAITER *waiter,
 		pos = cur;
 
 		/* Wait-Die: ensure younger waiters die. */
-		__ww_mutex_die(lock, cur, ww_ctx);
+		__ww_mutex_die(lock, cur, ww_ctx, wake_q);
 	}
 
 	__ww_waiter_add(lock, waiter, pos);

@@ -550,7 +557,7 @@ __ww_mutex_add_waiter(struct MUTEX_WAITER *waiter,
 		 * such that either we or the fastpath will wound @ww->ctx.
 		 */
 		smp_mb();
-		__ww_mutex_wound(lock, ww_ctx, ww->ctx);
+		__ww_mutex_wound(lock, ww_ctx, ww->ctx, wake_q);
 	}
 
 	return 0;

index 4ada158eb7ca..4c63a197f6fe 100644
@@ -573,6 +573,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 	DEFINE_WAKE_Q(wake_q);
 	struct mutex_waiter waiter;
 	struct ww_mutex *ww;
+	unsigned long flags;
 	int ret;
 
 	if (!use_ww_ctx)

@@ -615,7 +616,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 		return 0;
 	}
 
-	raw_spin_lock(&lock->wait_lock);
+	raw_spin_lock_irqsave(&lock->wait_lock, flags);
 	/*
 	 * After waiting to acquire the wait_lock, try again.
 	 */

@@ -676,7 +677,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 				goto err;
 		}
 
-		raw_spin_unlock(&lock->wait_lock);
+		raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
 		/* Make sure we do wakeups before calling schedule */
 		if (!wake_q_empty(&wake_q)) {
 			wake_up_q(&wake_q);

@@ -702,9 +703,9 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 			trace_contention_begin(lock, LCB_F_MUTEX);
 		}
 
-		raw_spin_lock(&lock->wait_lock);
+		raw_spin_lock_irqsave(&lock->wait_lock, flags);
 	}
-	raw_spin_lock(&lock->wait_lock);
+	raw_spin_lock_irqsave(&lock->wait_lock, flags);
 acquired:
 	__set_current_state(TASK_RUNNING);
 

@@ -730,7 +731,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 	if (ww_ctx)
 		ww_mutex_lock_acquired(ww, ww_ctx);
 
-	raw_spin_unlock(&lock->wait_lock);
+	raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
 	wake_up_q(&wake_q);
 	preempt_enable();
 	return 0;

@@ -740,7 +741,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 	__mutex_remove_waiter(lock, &waiter);
 err_early_kill:
 	trace_contention_end(lock, ret);
-	raw_spin_unlock(&lock->wait_lock);
+	raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
 	debug_mutex_free_waiter(&waiter);
 	mutex_release(&lock->dep_map, ip);
 	wake_up_q(&wake_q);

@@ -911,6 +912,7 @@ static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigne
 	struct task_struct *next = NULL;
 	DEFINE_WAKE_Q(wake_q);
 	unsigned long owner;
+	unsigned long flags;
 
 	mutex_release(&lock->dep_map, ip);
 

@@ -938,7 +940,7 @@ static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigne
 	}
 
 	preempt_disable();
-	raw_spin_lock(&lock->wait_lock);
+	raw_spin_lock_irqsave(&lock->wait_lock, flags);
 	debug_mutex_unlock(lock);
 	if (!list_empty(&lock->wait_list)) {
 		/* get the first entry from the wait-list: */

@@ -955,7 +957,7 @@ static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigne
 	if (owner & MUTEX_FLAG_HANDOFF)
 		__mutex_handoff(lock, next);
 
-	raw_spin_unlock(&lock->wait_lock);
+	raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
 	wake_up_q(&wake_q);
 	preempt_enable();
 }

index 7189c6631d90..8b94f4b89e74 100644
@@ -70,14 +70,14 @@ __ww_mutex_has_waiters(struct mutex *lock)
 	return atomic_long_read(&lock->owner) & MUTEX_FLAG_WAITERS;
 }
 
-static inline void lock_wait_lock(struct mutex *lock)
+static inline void lock_wait_lock(struct mutex *lock, unsigned long *flags)
 {
-	raw_spin_lock(&lock->wait_lock);
+	raw_spin_lock_irqsave(&lock->wait_lock, *flags);
 }
 
-static inline void unlock_wait_lock(struct mutex *lock)
+static inline void unlock_wait_lock(struct mutex *lock, unsigned long flags)
 {
-	raw_spin_unlock(&lock->wait_lock);
+	raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
 }
 
 static inline void lockdep_assert_wait_lock_held(struct mutex *lock)

@@ -144,14 +144,14 @@ __ww_mutex_has_waiters(struct rt_mutex *lock)
 	return rt_mutex_has_waiters(&lock->rtmutex);
 }
 
-static inline void lock_wait_lock(struct rt_mutex *lock)
+static inline void lock_wait_lock(struct rt_mutex *lock, unsigned long *flags)
 {
-	raw_spin_lock(&lock->rtmutex.wait_lock);
+	raw_spin_lock_irqsave(&lock->rtmutex.wait_lock, *flags);
 }
 
-static inline void unlock_wait_lock(struct rt_mutex *lock)
+static inline void unlock_wait_lock(struct rt_mutex *lock, flags)
 {
-	raw_spin_unlock(&lock->rtmutex.wait_lock);
+	raw_spin_unlock_irqrestore(&lock->rtmutex.wait_lock, flags);
 }
 
 static inline void lockdep_assert_wait_lock_held(struct rt_mutex *lock)

@@ -380,6 +380,7 @@ static __always_inline void
 ww_mutex_set_context_fastpath(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
 {
 	DEFINE_WAKE_Q(wake_q);
+	unsigned long flags;
 
 	ww_mutex_lock_acquired(lock, ctx);
 

@@ -408,10 +409,9 @@ ww_mutex_set_context_fastpath(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
 	 * Uh oh, we raced in fastpath, check if any of the waiters need to
 	 * die or wound us.
 	 */
-	lock_wait_lock(&lock->base);
+	lock_wait_lock(&lock->base, &flags);
 	__ww_mutex_check_waiters(&lock->base, ctx, &wake_q);
-	unlock_wait_lock(&lock->base);
-
+	unlock_wait_lock(&lock->base, flags);
 	wake_up_q(&wake_q);
 }
 

index 4c63a197f6fe..2c5d1a9cf767 100644
@@ -56,31 +56,6 @@ __mutex_init(struct mutex *lock, const char *name, struct lock_class_key *key)
 }
 EXPORT_SYMBOL(__mutex_init);
 
-/*
- * @owner: contains: 'struct task_struct *' to the current lock owner,
- * NULL means not owned. Since task_struct pointers are aligned at
- * at least L1_CACHE_BYTES, we have low bits to store extra state.
- *
- * Bit0 indicates a non-empty waiter list; unlock must issue a wakeup.
- * Bit1 indicates unlock needs to hand the lock to the top-waiter
- * Bit2 indicates handoff has been done and we're waiting for pickup.
- */
-#define MUTEX_FLAG_WAITERS	0x01
-#define MUTEX_FLAG_HANDOFF	0x02
-#define MUTEX_FLAG_PICKUP	0x04
-
-#define MUTEX_FLAGS		0x07
-
-/*
- * Internal helper function; C doesn't allow us to hide it :/
- *
- * DO NOT USE (outside of mutex code).
- */
-static inline struct task_struct *__mutex_owner(struct mutex *lock)
-{
-	return (struct task_struct *)(atomic_long_read(&lock->owner) & ~MUTEX_FLAGS);
-}
-
 static inline struct task_struct *__owner_task(unsigned long owner)
 {
 	return (struct task_struct *)(owner & ~MUTEX_FLAGS);

index 0b2a79c4013b..1c7d3d32def8 100644
@@ -20,6 +20,31 @@ struct mutex_waiter {
 #endif
 };
 
+/*
+ * @owner: contains: 'struct task_struct *' to the current lock owner,
+ * NULL means not owned. Since task_struct pointers are aligned at
+ * at least L1_CACHE_BYTES, we have low bits to store extra state.
+ *
+ * Bit0 indicates a non-empty waiter list; unlock must issue a wakeup.
+ * Bit1 indicates unlock needs to hand the lock to the top-waiter
+ * Bit2 indicates handoff has been done and we're waiting for pickup.
+ */
+#define MUTEX_FLAG_WAITERS	0x01
+#define MUTEX_FLAG_HANDOFF	0x02
+#define MUTEX_FLAG_PICKUP	0x04
+
+#define MUTEX_FLAGS		0x07
+
+/*
+ * Internal helper function; C doesn't allow us to hide it :/
+ *
+ * DO NOT USE (outside of mutex & scheduler code).
+ */
+static inline struct task_struct *__mutex_owner(struct mutex *lock)
+{
+	return (struct task_struct *)(atomic_long_read(&lock->owner) & ~MUTEX_FLAGS);
+}
+
 #ifdef CONFIG_DEBUG_MUTEXES
 extern void debug_mutex_lock_common(struct mutex *lock,
 				    struct mutex_waiter *waiter);

index 4f5b0710c0f1..22a6ac47d5fb 100644
@@ -1145,10 +1145,7 @@ struct task_struct {
 	struct rt_mutex_waiter		*pi_blocked_on;
 #endif
 
-#ifdef CONFIG_DEBUG_MUTEXES
-	/* Mutex deadlock detection: */
-	struct mutex_waiter		*blocked_on;
-#endif
+	struct mutex			*blocked_on;	/* lock we're blocked on */
 
 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
 	int				non_block_count;

index 3b6d20dfb9a8..1c3f7eaa9239 100644
@@ -2455,9 +2455,8 @@ __latent_entropy struct task_struct *copy_process(
 	lockdep_init_task(p);
 #endif
 
-#ifdef CONFIG_DEBUG_MUTEXES
 	p->blocked_on = NULL; /* not blocked yet */
-#endif
+
 #ifdef CONFIG_BCACHE
 	p->sequential_io	= 0;
 	p->sequential_io_avg	= 0;

index bc8abb8549d2..7228909c3e62 100644
@@ -52,17 +52,18 @@ void debug_mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter,
 {
 	lockdep_assert_held(&lock->wait_lock);
 
-	/* Mark the current thread as blocked on the lock: */
-	task->blocked_on = waiter;
+	/* Current thread can't be already blocked (since it's executing!) */
+	DEBUG_LOCKS_WARN_ON(task->blocked_on);
 }
 
 void debug_mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
 			 struct task_struct *task)
 {
+	struct mutex *blocked_on = READ_ONCE(task->blocked_on);
+
 	DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list));
 	DEBUG_LOCKS_WARN_ON(waiter->task != task);
-	DEBUG_LOCKS_WARN_ON(task->blocked_on != waiter);
-	task->blocked_on = NULL;
+	DEBUG_LOCKS_WARN_ON(blocked_on && blocked_on != lock);
 
 	INIT_LIST_HEAD(&waiter->list);
 	waiter->task = NULL;

index 2c5d1a9cf767..73064e4865b7 100644
@@ -622,6 +622,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 			goto err_early_kill;
 	}
 
+	current->blocked_on = lock;
 	set_current_state(state);
 	trace_contention_begin(lock, LCB_F_MUTEX);
 	for (;;) {

@@ -662,6 +663,10 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 
 		first = __mutex_waiter_is_first(lock, &waiter);
 
+		/*
+		 * Gets reset by unlock path().
+		 */
+		current->blocked_on = lock;
 		set_current_state(state);
 		/*
 		 * Here we order against unlock; we must either see it change

@@ -682,6 +687,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 	}
 	raw_spin_lock_irqsave(&lock->wait_lock, flags);
 acquired:
+	current->blocked_on = NULL;
 	__set_current_state(TASK_RUNNING);
 
 	if (ww_ctx) {

@@ -712,9 +718,11 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 	return 0;
 
 err:
+	current->blocked_on = NULL;
 	__set_current_state(TASK_RUNNING);
 	__mutex_remove_waiter(lock, &waiter);
 err_early_kill:
+	WARN_ON(current->blocked_on);
 	trace_contention_end(lock, ret);
 	raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
 	debug_mutex_free_waiter(&waiter);

@@ -926,6 +934,8 @@ static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigne
 		next = waiter->task;
 
 		debug_mutex_wake_waiter(lock, waiter);
+		WARN_ON(next->blocked_on != lock);
+		next->blocked_on = NULL;
 		wake_q_add(&wake_q, next);
 	}
 

index 8b94f4b89e74..8bb334491732 100644
@@ -284,6 +284,13 @@ __ww_mutex_die(struct MUTEX *lock, struct MUTEX_WAITER *waiter,
 #ifndef WW_RT
 		debug_mutex_wake_waiter(lock, waiter);
 #endif
+		/*
+		 * When waking up the task to die, be sure to clear the
+		 * blocked_on pointer. Otherwise we can see circular
+		 * blocked_on relationships that can't resolve.
+		 */
+		WARN_ON(waiter->task->blocked_on != lock);
+		waiter->task->blocked_on = NULL;
 		wake_q_add(wake_q, waiter->task);
 	}
 

@@ -331,9 +338,15 @@ static bool __ww_mutex_wound(struct MUTEX *lock,
 		 * it's wounded in __ww_mutex_check_kill() or has a
 		 * wakeup pending to re-read the wounded state.
 		 */
-		if (owner != current)
+		if (owner != current) {
+			/*
+			 * When waking up the task to wound, be sure to clear the
+			 * blocked_on pointer. Otherwise we can see circular
+			 * blocked_on relationships that can't resolve.
+			 */
+			owner->blocked_on = NULL;
 			wake_q_add(wake_q, owner);
-
+		}
 		return true;
 	}
 

index 22a6ac47d5fb..a9258dae00e0 100644
@@ -1146,6 +1146,7 @@ struct task_struct {
 #endif
 
 	struct mutex			*blocked_on;	/* lock we're blocked on */
+	raw_spinlock_t			blocked_lock;
 
 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
 	int				non_block_count;

index ff6c4b9bfe6b..189ce67e9704 100644
@@ -130,6 +130,7 @@ struct task_struct init_task
 	.journal_info	= NULL,
 	INIT_CPU_TIMERS(init_task)
 	.pi_lock	= __RAW_SPIN_LOCK_UNLOCKED(init_task.pi_lock),
+	.blocked_lock	= __RAW_SPIN_LOCK_UNLOCKED(init_task.blocked_lock),
 	.timer_slack_ns = 50000, /* 50 usec default slack */
 	.thread_pid	= &init_struct_pid,
 	.thread_group	= LIST_HEAD_INIT(init_task.thread_group),

index 1c3f7eaa9239..47b76ed5ddf6 100644
@@ -2353,6 +2353,7 @@ __latent_entropy struct task_struct *copy_process(
 	ftrace_graph_init_task(p);
 
 	rt_mutex_init_task(p);
+	raw_spin_lock_init(&p->blocked_lock);
 
 	lockdep_assert_irqs_enabled();
 #ifdef CONFIG_PROVE_LOCKING

index 73064e4865b7..df186c0bf4a9 100644
@@ -592,6 +592,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 	}
 
 	raw_spin_lock_irqsave(&lock->wait_lock, flags);
+	raw_spin_lock(&current->blocked_lock);
 	/*
 	 * After waiting to acquire the wait_lock, try again.
 	 */

@@ -653,6 +654,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 				goto err;
 		}
 
+		raw_spin_unlock(&current->blocked_lock);
 		raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
 		/* Make sure we do wakeups before calling schedule */
 		if (!wake_q_empty(&wake_q)) {

@@ -663,6 +665,8 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 
 		first = __mutex_waiter_is_first(lock, &waiter);
 
+		raw_spin_lock_irqsave(&lock->wait_lock, flags);
+		raw_spin_lock(&current->blocked_lock);
 		/*
 		 * Gets reset by unlock path().
 		 */

@@ -677,15 +681,23 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 			break;
 
 		if (first) {
+			bool acquired;
+
+			/*
+			 * mutex_optimistic_spin() can schedule, so  we need to
+			 * release these locks before calling it.
+			 */
+			raw_spin_unlock(&current->blocked_lock);
+			raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
 			trace_contention_begin(lock, LCB_F_MUTEX | LCB_F_SPIN);
-			if (mutex_optimistic_spin(lock, ww_ctx, &waiter))
+			acquired = mutex_optimistic_spin(lock, ww_ctx, &waiter);
+			raw_spin_lock_irqsave(&lock->wait_lock, flags);
+			raw_spin_lock(&current->blocked_lock);
+			if (acquired)
 				break;
 			trace_contention_begin(lock, LCB_F_MUTEX);
 		}
-
-		raw_spin_lock_irqsave(&lock->wait_lock, flags);
 	}
-	raw_spin_lock_irqsave(&lock->wait_lock, flags);
 acquired:
 	current->blocked_on = NULL;
 	__set_current_state(TASK_RUNNING);

@@ -712,6 +724,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 	if (ww_ctx)
 		ww_mutex_lock_acquired(ww, ww_ctx);
 
+	raw_spin_unlock(&current->blocked_lock);
 	raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
 	wake_up_q(&wake_q);
 	preempt_enable();

@@ -724,6 +737,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 err_early_kill:
 	WARN_ON(current->blocked_on);
 	trace_contention_end(lock, ret);
+	raw_spin_unlock(&current->blocked_lock);
 	raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
 	debug_mutex_free_waiter(&waiter);
 	mutex_release(&lock->dep_map, ip);

@@ -934,8 +948,10 @@ static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigne
 		next = waiter->task;
 
 		debug_mutex_wake_waiter(lock, waiter);
+		raw_spin_lock(&next->blocked_lock);
 		WARN_ON(next->blocked_on != lock);
 		next->blocked_on = NULL;
+		raw_spin_unlock(&next->blocked_lock);
 		wake_q_add(&wake_q, next);
 	}
 

index 8bb334491732..2929a95b4272 100644
@@ -281,6 +281,8 @@ __ww_mutex_die(struct MUTEX *lock, struct MUTEX_WAITER *waiter,
 		return false;
 
 	if (waiter->ww_ctx->acquired > 0 && __ww_ctx_less(waiter->ww_ctx, ww_ctx)) {
+		/* nested as we should hold current->blocked_lock already */
+		raw_spin_lock_nested(&waiter->task->blocked_lock, SINGLE_DEPTH_NESTING);
 #ifndef WW_RT
 		debug_mutex_wake_waiter(lock, waiter);
 #endif

@@ -292,6 +294,7 @@ __ww_mutex_die(struct MUTEX *lock, struct MUTEX_WAITER *waiter,
 		WARN_ON(waiter->task->blocked_on != lock);
 		waiter->task->blocked_on = NULL;
 		wake_q_add(wake_q, waiter->task);
+		raw_spin_unlock(&waiter->task->blocked_lock);
 	}
 
 	return true;

@@ -339,6 +342,8 @@ static bool __ww_mutex_wound(struct MUTEX *lock,
 		 * wakeup pending to re-read the wounded state.
 		 */
 		if (owner != current) {
+			/* nested as we should hold current->blocked_lock already */
+			raw_spin_lock_nested(&owner->blocked_lock, SINGLE_DEPTH_NESTING);
 			/*
 			 * When waking up the task to wound, be sure to clear the
 			 * blocked_on pointer. Otherwise we can see circular

@@ -346,6 +351,7 @@ static bool __ww_mutex_wound(struct MUTEX *lock,
 			 */
 			owner->blocked_on = NULL;
 			wake_q_add(wake_q, owner);
+			raw_spin_unlock(&owner->blocked_lock);
 		}
 		return true;
 	}

index a9258dae00e0..81334677e008 100644
@@ -2248,6 +2248,28 @@ static inline int rwlock_needbreak(rwlock_t *lock)
 #endif
 }
 
+static inline void set_task_blocked_on(struct task_struct *p, struct mutex *m)
+{
+	lockdep_assert_held(&p->blocked_lock);
+
+	/* We should be setting values to NULL or NULL to values */
+	WARN_ON((!m && !p->blocked_on) || (m && p->blocked_on));
+
+	p->blocked_on = m;
+}
+
+static inline struct mutex *get_task_blocked_on(struct task_struct *p)
+{
+	lockdep_assert_held(&p->blocked_lock);
+
+	return p->blocked_on;
+}
+
+static inline struct mutex *get_task_blocked_on_once(struct task_struct *p)
+{
+	return READ_ONCE(p->blocked_on);
+}
+
 static __always_inline bool need_resched(void)
 {
 	return unlikely(tif_need_resched());

index 7228909c3e62..1eedf7c60c00 100644
@@ -53,13 +53,13 @@ void debug_mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter,
 	lockdep_assert_held(&lock->wait_lock);
 
 	/* Current thread can't be already blocked (since it's executing!) */
-	DEBUG_LOCKS_WARN_ON(task->blocked_on);
+	DEBUG_LOCKS_WARN_ON(get_task_blocked_on(task));
 }
 
 void debug_mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
 			 struct task_struct *task)
 {
-	struct mutex *blocked_on = READ_ONCE(task->blocked_on);
+	struct mutex *blocked_on = get_task_blocked_on_once(task);
 
 	DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list));
 	DEBUG_LOCKS_WARN_ON(waiter->task != task);

index df186c0bf4a9..36e563f69705 100644
@@ -623,7 +623,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 			goto err_early_kill;
 	}
 
-	current->blocked_on = lock;
+	set_task_blocked_on(current, lock);
 	set_current_state(state);
 	trace_contention_begin(lock, LCB_F_MUTEX);
 	for (;;) {

@@ -670,7 +670,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 		/*
 		 * Gets reset by unlock path().
 		 */
-		current->blocked_on = lock;
+		set_task_blocked_on(current, lock);
 		set_current_state(state);
 		/*
 		 * Here we order against unlock; we must either see it change

@@ -699,7 +699,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 		}
 	}
 acquired:
-	current->blocked_on = NULL;
+	set_task_blocked_on(current, NULL);
 	__set_current_state(TASK_RUNNING);
 
 	if (ww_ctx) {

@@ -731,7 +731,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 	return 0;
 
 err:
-	current->blocked_on = NULL;
+	set_task_blocked_on(current, NULL);
 	__set_current_state(TASK_RUNNING);
 	__mutex_remove_waiter(lock, &waiter);
 err_early_kill:

@@ -950,7 +950,7 @@ static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigne
 		debug_mutex_wake_waiter(lock, waiter);
 		raw_spin_lock(&next->blocked_lock);
 		WARN_ON(next->blocked_on != lock);
-		next->blocked_on = NULL;
+		set_task_blocked_on(current, NULL);
 		raw_spin_unlock(&next->blocked_lock);
 		wake_q_add(&wake_q, next);
 	}

index 2929a95b4272..44a532dda927 100644
@@ -292,7 +292,7 @@ __ww_mutex_die(struct MUTEX *lock, struct MUTEX_WAITER *waiter,
 		 * blocked_on relationships that can't resolve.
 		 */
 		WARN_ON(waiter->task->blocked_on != lock);
-		waiter->task->blocked_on = NULL;
+		set_task_blocked_on(waiter->task, NULL);
 		wake_q_add(wake_q, waiter->task);
 		raw_spin_unlock(&waiter->task->blocked_lock);
 	}

@@ -349,7 +349,7 @@ static bool __ww_mutex_wound(struct MUTEX *lock,
 			 * blocked_on pointer. Otherwise we can see circular
 			 * blocked_on relationships that can't resolve.
 			 */
-			owner->blocked_on = NULL;
+			set_task_blocked_on(owner, NULL);
 			wake_q_add(wake_q, owner);
 			raw_spin_unlock(&owner->blocked_lock);
 		}

index 81334677e008..5f05d9a4cc3f 100644
@@ -1551,6 +1551,19 @@ struct task_struct {
 	 */
 };
 
+#ifdef CONFIG_PROXY_EXEC
+DECLARE_STATIC_KEY_TRUE(__sched_proxy_exec);
+static inline bool sched_proxy_exec(void)
+{
+	return static_branch_likely(&__sched_proxy_exec);
+}
+#else
+static inline bool sched_proxy_exec(void)
+{
+	return false;
+}
+#endif
+
 static inline struct pid *task_pid(struct task_struct *task)
 {
 	return task->thread_pid;

index 802551e0009b..a38bf8ef5798 100644
@@ -117,6 +117,37 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(sched_update_nr_running_tp);
 
 DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
 
+#ifdef CONFIG_PROXY_EXEC
+DEFINE_STATIC_KEY_TRUE(__sched_proxy_exec);
+static int __init setup_proxy_exec(char *str)
+{
+	int ret = 0;
+
+	if (!str)
+		goto out;
+
+	if (!strcmp(str, "enable")) {
+		static_branch_enable(&__sched_proxy_exec);
+		ret = 1;
+	} else if (!strcmp(str, "disable")) {
+		static_branch_disable(&__sched_proxy_exec);
+		ret = 1;
+	}
+out:
+	if (!ret)
+		pr_warn("Unable to parse proxy_exec=\n");
+
+	return ret;
+}
+#else
+static int __init setup_proxy_exec(char *str)
+{
+	pr_warn("CONFIG_PROXY_EXEC=n, so it cannot be enabled or disabled at boottime\n");
+	return 0;
+}
+#endif
+__setup("proxy_exec=", setup_proxy_exec);
+
 #ifdef CONFIG_SCHED_DEBUG
 /*
  * Debugging: various feature bits

index 5f05d9a4cc3f..47c7095b918a 100644
@@ -1146,6 +1146,7 @@ struct task_struct {
 #endif
 
 	struct mutex			*blocked_on;	/* lock we're blocked on */
+	bool				blocked_on_waking; /* blocked on, but waking */
 	raw_spinlock_t			blocked_lock;
 
 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP

@@ -2269,6 +2270,7 @@ static inline void set_task_blocked_on(struct task_struct *p, struct mutex *m)
 	WARN_ON((!m && !p->blocked_on) || (m && p->blocked_on));
 
 	p->blocked_on = m;
+	p->blocked_on_waking = false;
 }
 
 static inline struct mutex *get_task_blocked_on(struct task_struct *p)

index 47b76ed5ddf6..930947bf4569 100644
@@ -2457,6 +2457,7 @@ __latent_entropy struct task_struct *copy_process(
 #endif
 
 	p->blocked_on = NULL; /* not blocked yet */
+	p->blocked_on_waking = false; /* not blocked yet */
 
 #ifdef CONFIG_BCACHE
 	p->sequential_io	= 0;

index 36e563f69705..f37b7afe8aa5 100644
@@ -667,10 +667,11 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
 
 		raw_spin_lock_irqsave(&lock->wait_lock, flags);
 		raw_spin_lock(&current->blocked_lock);
+
 		/*
-		 * Gets reset by unlock path().
+		 * Clear blocked_on_waking flag set by the unlock path().
 		 */
-		set_task_blocked_on(current, lock);
+		current->blocked_on_waking = false;
 		set_current_state(state);
 		/*
 		 * Here we order against unlock; we must either see it change

@@ -950,7 +951,7 @@ static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigne
 		debug_mutex_wake_waiter(lock, waiter);
 		raw_spin_lock(&next->blocked_lock);
 		WARN_ON(next->blocked_on != lock);
-		set_task_blocked_on(current, NULL);
+		next->blocked_on_waking = true;
 		raw_spin_unlock(&next->blocked_lock);
 		wake_q_add(&wake_q, next);
 	}

index 44a532dda927..3b0a68d7e308 100644
@@ -287,12 +287,12 @@ __ww_mutex_die(struct MUTEX *lock, struct MUTEX_WAITER *waiter,
 		debug_mutex_wake_waiter(lock, waiter);
 #endif
 		/*
-		 * When waking up the task to die, be sure to clear the
-		 * blocked_on pointer. Otherwise we can see circular
+		 * When waking up the task to die, be sure to set the
+		 * blocked_on_waking flag. Otherwise we can see circular
 		 * blocked_on relationships that can't resolve.
 		 */
 		WARN_ON(waiter->task->blocked_on != lock);
-		set_task_blocked_on(waiter->task, NULL);
+		waiter->task->blocked_on_waking = true;
 		wake_q_add(wake_q, waiter->task);
 		raw_spin_unlock(&waiter->task->blocked_lock);
 	}

@@ -345,11 +345,11 @@ static bool __ww_mutex_wound(struct MUTEX *lock,
 			/* nested as we should hold current->blocked_lock already */
 			raw_spin_lock_nested(&owner->blocked_lock, SINGLE_DEPTH_NESTING);
 			/*
-			 * When waking up the task to wound, be sure to clear the
-			 * blocked_on pointer. Otherwise we can see circular
+			 * When waking up the task to wound, be sure to set the
+			 * blocked_on_waking flag. Otherwise we can see circular
 			 * blocked_on relationships that can't resolve.
 			 */
-			set_task_blocked_on(owner, NULL);
+			owner->blocked_on_waking = true;
 			wake_q_add(wake_q, owner);
 			raw_spin_unlock(&owner->blocked_lock);
 		}

index 1def5b7fa1df..7c37d478e0f8 100644
@@ -2133,6 +2133,18 @@ static inline int task_current(struct rq *rq, struct task_struct *p)
 	return rq->curr == p;
 }
 
+#ifdef CONFIG_PROXY_EXEC
+static inline bool task_is_blocked(struct task_struct *p)
+{
+	return sched_proxy_exec() && !!p->blocked_on && !p->blocked_on_waking;
+}
+#else /* !PROXY_EXEC */
+static inline bool task_is_blocked(struct task_struct *p)
+{
+	return false;
+}
+#endif /* PROXY_EXEC */
+
 static inline int task_on_cpu(struct rq *rq, struct task_struct *p)
 {
 #ifdef CONFIG_SMP

index f37b7afe8aa5..5394a3c4b5d9 100644
@@ -914,26 +914,31 @@ static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigne
 
 	mutex_release(&lock->dep_map, ip);
 
-	/*
-	 * Release the lock before (potentially) taking the spinlock such that
-	 * other contenders can get on with things ASAP.
-	 *
-	 * Except when HANDOFF, in that case we must not clear the owner field,
-	 * but instead set it to the top waiter.
-	 */
-	owner = atomic_long_read(&lock->owner);
-	for (;;) {
-		MUTEX_WARN_ON(__owner_task(owner) != current);
-		MUTEX_WARN_ON(owner & MUTEX_FLAG_PICKUP);
-
-		if (owner & MUTEX_FLAG_HANDOFF)
-			break;
+	if (sched_proxy_exec()) {
+		/* Always force HANDOFF for Proxy Exec for now. Revisit. */
+		owner = MUTEX_FLAG_HANDOFF;
+	} else {
+		/*
+		 * Release the lock before (potentially) taking the spinlock
+		 * such that other contenders can get on with things ASAP.
+		 *
+		 * Except when HANDOFF, in that case we must not clear the
+		 * owner field, but instead set it to the top waiter.
+		 */
+		owner = atomic_long_read(&lock->owner);
+		for (;;) {
+			MUTEX_WARN_ON(__owner_task(owner) != current);
+			MUTEX_WARN_ON(owner & MUTEX_FLAG_PICKUP);
 
-		if (atomic_long_try_cmpxchg_release(&lock->owner, &owner, __owner_flags(owner))) {
-			if (owner & MUTEX_FLAG_WAITERS)
+			if (owner & MUTEX_FLAG_HANDOFF)
 				break;
 
-			return;
+			if (atomic_long_try_cmpxchg_release(&lock->owner, &owner,
+							    __owner_flags(owner))) {
+				if (owner & MUTEX_FLAG_WAITERS)
+					break;
+				return;
+			}
 		}
 	}
 

index a38bf8ef5798..9931940ba474 100644
@@ -824,7 +824,7 @@ static enum hrtimer_restart hrtick(struct hrtimer *timer)
 
 	rq_lock(rq, &rf);
 	update_rq_clock(rq);
-	rq->curr->sched_class->task_tick(rq, rq->curr, 1);
+	rq_selected(rq)->sched_class->task_tick(rq, rq_selected(rq), 1);
 	rq_unlock(rq, &rf);
 
 	return HRTIMER_NORESTART;

@@ -2251,16 +2251,18 @@ static inline void check_class_changed(struct rq *rq, struct task_struct *p,
 
 void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags)
 {
-	if (p->sched_class == rq->curr->sched_class)
-		rq->curr->sched_class->check_preempt_curr(rq, p, flags);
-	else if (sched_class_above(p->sched_class, rq->curr->sched_class))
+	struct task_struct *curr = rq_selected(rq);
+
+	if (p->sched_class == curr->sched_class)
+		curr->sched_class->check_preempt_curr(rq, p, flags);
+	else if (sched_class_above(p->sched_class, curr->sched_class))
 		resched_curr(rq);
 
 	/*
 	 * A queue event has occurred, and we're going to schedule.  In
 	 * this case, we can save a useless back to back clock update.
 	 */
-	if (task_on_rq_queued(rq->curr) && test_tsk_need_resched(rq->curr))
+	if (task_on_rq_queued(curr) && test_tsk_need_resched(rq->curr))
 		rq_clock_skip_update(rq);
 }
 

@@ -2799,7 +2801,7 @@ __do_set_cpus_allowed(struct task_struct *p, struct affinity_context *ctx)
 		lockdep_assert_held(&p->pi_lock);
 
 	queued = task_on_rq_queued(p);
-	running = task_current(rq, p);
+	running = task_current_selected(rq, p);
 
 	if (queued) {
 		/*

@@ -5602,7 +5604,7 @@ unsigned long long task_sched_runtime(struct task_struct *p)
 	 * project cycles that may never be accounted to this
 	 * thread, breaking clock_gettime().
 	 */
-	if (task_current(rq, p) && task_on_rq_queued(p)) {
+	if (task_current_selected(rq, p) && task_on_rq_queued(p)) {
 		prefetch_curr_exec_start(p);
 		update_rq_clock(rq);
 		p->sched_class->update_curr(rq);

@@ -5670,7 +5672,8 @@ void scheduler_tick(void)
 {
 	int cpu = smp_processor_id();
 	struct rq *rq = cpu_rq(cpu);
-	struct task_struct *curr = rq->curr;
+	/* accounting goes to the selected task */
+	struct task_struct *curr;
 	struct rq_flags rf;
 	unsigned long thermal_pressure;
 	u64 resched_latency;

@@ -5681,6 +5684,7 @@ void scheduler_tick(void)
 	sched_clock_tick();
 
 	rq_lock(rq, &rf);
+	curr = rq_selected(rq);
 
 	update_rq_clock(rq);
 	thermal_pressure = arch_scale_thermal_pressure(cpu_of(rq));

@@ -5765,6 +5769,12 @@ static void sched_tick_remote(struct work_struct *work)
 		struct task_struct *curr = rq->curr;
 
 		if (cpu_online(cpu)) {
+			/*
+			 * Since this is a remote tick for full dynticks mode,
+			 * we are always sure that there is no proxy (only a
+			 * single task is running).
+			 */
+			SCHED_WARN_ON(rq->curr != rq_selected(rq));
 			update_rq_clock(rq);
 
 			if (!is_idle_task(curr)) {

@@ -6688,6 +6698,7 @@ static void __sched notrace __schedule(unsigned int sched_mode)
 	}
 
 	next = pick_next_task(rq, prev, &rf);
+	rq_set_selected(rq, next);
 	clear_tsk_need_resched(prev);
 	clear_preempt_need_resched();
 #ifdef CONFIG_SCHED_DEBUG

@@ -7154,7 +7165,7 @@ void rt_mutex_setprio(struct task_struct *p, struct task_struct *pi_task)
 
 	prev_class = p->sched_class;
 	queued = task_on_rq_queued(p);
-	running = task_current(rq, p);
+	running = task_current_selected(rq, p);
 	if (queued)
 		dequeue_task(rq, p, queue_flag);
 	if (running)

@@ -7242,7 +7253,7 @@ void set_user_nice(struct task_struct *p, long nice)
 		goto out_unlock;
 	}
 	queued = task_on_rq_queued(p);
-	running = task_current(rq, p);
+	running = task_current_selected(rq, p);
 	if (queued)
 		dequeue_task(rq, p, DEQUEUE_SAVE | DEQUEUE_NOCLOCK);
 	if (running)

@@ -7826,7 +7837,7 @@ static int __sched_setscheduler(struct task_struct *p,
 	}
 
 	queued = task_on_rq_queued(p);
-	running = task_current(rq, p);
+	running = task_current_selected(rq, p);
 	if (queued)
 		dequeue_task(rq, p, queue_flags);
 	if (running)

@@ -9327,6 +9338,7 @@ void __init init_idle(struct task_struct *idle, int cpu)
 	rcu_read_unlock();
 
 	rq->idle = idle;
+	rq_set_selected(rq, idle);
 	rcu_assign_pointer(rq->curr, idle);
 	idle->on_rq = TASK_ON_RQ_QUEUED;
 #ifdef CONFIG_SMP

@@ -9416,7 +9428,7 @@ void sched_setnuma(struct task_struct *p, int nid)
 
 	rq = task_rq_lock(p, &rf);
 	queued = task_on_rq_queued(p);
-	running = task_current(rq, p);
+	running = task_current_selected(rq, p);
 
 	if (queued)
 		dequeue_task(rq, p, DEQUEUE_SAVE);

@@ -10543,7 +10555,7 @@ void sched_move_task(struct task_struct *tsk)
 
 	update_rq_clock(rq);
 
-	running = task_current(rq, tsk);
+	running = task_current_selected(rq, tsk);
 	queued = task_on_rq_queued(tsk);
 
 	if (queued)

index 9522e6607754..e8bca6b8da6f 100644
@@ -1174,7 +1174,7 @@ static enum hrtimer_restart dl_task_timer(struct hrtimer *timer)
 #endif
 
 	enqueue_task_dl(rq, p, ENQUEUE_REPLENISH);
-	if (dl_task(rq->curr))
+	if (dl_task(rq_selected(rq)))
 		check_preempt_curr_dl(rq, p, 0);
 	else
 		resched_curr(rq);

@@ -1297,7 +1297,7 @@ static u64 grub_reclaim(u64 delta, struct rq *rq, struct sched_dl_entity *dl_se)
  */
 static void update_curr_dl(struct rq *rq)
 {
-	struct task_struct *curr = rq->curr;
+	struct task_struct *curr = rq_selected(rq);
 	struct sched_dl_entity *dl_se = &curr->dl;
 	s64 delta_exec, scaled_delta_exec;
 	int cpu = cpu_of(rq);

@@ -1810,7 +1810,7 @@ static int find_later_rq(struct task_struct *task);
 static int
 select_task_rq_dl(struct task_struct *p, int cpu, int flags)
 {
-	struct task_struct *curr;
+	struct task_struct *curr, *selected;
 	bool select_rq;
 	struct rq *rq;
 

@@ -1821,6 +1821,7 @@ select_task_rq_dl(struct task_struct *p, int cpu, int flags)
 
 	rcu_read_lock();
 	curr = READ_ONCE(rq->curr); /* unlocked access */
+	selected = READ_ONCE(rq_selected(rq));
 
 	/*
 	 * If we are dealing with a -deadline task, we must

@@ -1831,9 +1832,9 @@ select_task_rq_dl(struct task_struct *p, int cpu, int flags)
 	 * other hand, if it has a shorter deadline, we
 	 * try to make it stay here, it might be important.
 	 */
-	select_rq = unlikely(dl_task(curr)) &&
+	select_rq = unlikely(dl_task(selected)) &&
 		    (curr->nr_cpus_allowed < 2 ||
-		     !dl_entity_preempt(&p->dl, &curr->dl)) &&
+		     !dl_entity_preempt(&p->dl, &selected->dl)) &&
 		    p->nr_cpus_allowed > 1;
 
 	/*

@@ -1896,7 +1897,7 @@ static void check_preempt_equal_dl(struct rq *rq, struct task_struct *p)
 	 * let's hope p can move out.
 	 */
 	if (rq->curr->nr_cpus_allowed == 1 ||
-	    !cpudl_find(&rq->rd->cpudl, rq->curr, NULL))
+	    !cpudl_find(&rq->rd->cpudl, rq_selected(rq), NULL))
 		return;
 
 	/*

@@ -1935,7 +1936,7 @@ static int balance_dl(struct rq *rq, struct task_struct *p, struct rq_flags *rf)
 static void check_preempt_curr_dl(struct rq *rq, struct task_struct *p,
 				  int flags)
 {
-	if (dl_entity_preempt(&p->dl, &rq->curr->dl)) {
+	if (dl_entity_preempt(&p->dl, &rq_selected(rq)->dl)) {
 		resched_curr(rq);
 		return;
 	}

@@ -1945,7 +1946,7 @@ static void check_preempt_curr_dl(struct rq *rq, struct task_struct *p,
 	 * In the unlikely case current and p have the same deadline
 	 * let us try to decide what's the best thing to do...
 	 */
-	if ((p->dl.deadline == rq->curr->dl.deadline) &&
+	if ((p->dl.deadline == rq_selected(rq)->dl.deadline) &&
 	    !test_tsk_need_resched(rq->curr))
 		check_preempt_equal_dl(rq, p);
 #endif /* CONFIG_SMP */

@@ -1980,7 +1981,7 @@ static void set_next_task_dl(struct rq *rq, struct task_struct *p, bool first)
 	if (hrtick_enabled_dl(rq))
 		start_hrtick_dl(rq, p);
 
-	if (rq->curr->sched_class != &dl_sched_class)
+	if (rq_selected(rq)->sched_class != &dl_sched_class)
 		update_dl_rq_load_avg(rq_clock_pelt(rq), rq, 0);
 
 	deadline_queue_push_tasks(rq);

@@ -2297,8 +2298,8 @@ static int push_dl_task(struct rq *rq)
 	 * can move away, it makes sense to just reschedule
 	 * without going further in pushing next_task.
 	 */
-	if (dl_task(rq->curr) &&
-	    dl_time_before(next_task->dl.deadline, rq->curr->dl.deadline) &&
+	if (dl_task(rq_selected(rq)) &&
+	    dl_time_before(next_task->dl.deadline, rq_selected(rq)->dl.deadline) &&
 	    rq->curr->nr_cpus_allowed > 1) {
 		resched_curr(rq);
 		return 0;

@@ -2423,7 +2424,7 @@ static void pull_dl_task(struct rq *this_rq)
 			 * deadline than the current task of its runqueue.
 			 */
 			if (dl_time_before(p->dl.deadline,
-					   src_rq->curr->dl.deadline))
+					   rq_selected(src_rq)->dl.deadline))
 				goto skip;
 
 			if (is_migration_disabled(p)) {

@@ -2462,9 +2463,9 @@ static void task_woken_dl(struct rq *rq, struct task_struct *p)
 	if (!task_on_cpu(rq, p) &&
 	    !test_tsk_need_resched(rq->curr) &&
 	    p->nr_cpus_allowed > 1 &&
-	    dl_task(rq->curr) &&
+	    dl_task(rq_selected(rq)) &&
 	    (rq->curr->nr_cpus_allowed < 2 ||
-	     !dl_entity_preempt(&p->dl, &rq->curr->dl))) {
+	     !dl_entity_preempt(&p->dl, &rq_selected(rq)->dl))) {
 		push_dl_tasks(rq);
 	}
 }

@@ -2639,12 +2640,12 @@ static void switched_to_dl(struct rq *rq, struct task_struct *p)
 		return;
 	}
 
-	if (rq->curr != p) {
+	if (rq_selected(rq) != p) {
 #ifdef CONFIG_SMP
 		if (p->nr_cpus_allowed > 1 && rq->dl.overloaded)
 			deadline_queue_push_tasks(rq);
 #endif
-		if (dl_task(rq->curr))
+		if (dl_task(rq_selected(rq)))
 			check_preempt_curr_dl(rq, p, 0);
 		else
 			resched_curr(rq);

@@ -2673,7 +2674,7 @@ static void prio_changed_dl(struct rq *rq, struct task_struct *p,
 	if (!rq->dl.overloaded)
 		deadline_queue_pull_task(rq);
 
-	if (task_current(rq, p)) {
+	if (task_current_selected(rq, p)) {
 		/*
 		 * If we now have a earlier deadline task than p,
 		 * then reschedule, provided p is still on this

index c919633acd3d..3d5c1ec34bf7 100644
@@ -1172,7 +1172,7 @@ static s64 update_curr_se(struct rq *rq, struct sched_entity *curr)
  */
 s64 update_curr_common(struct rq *rq)
 {
-	struct task_struct *curr = rq->curr;
+	struct task_struct *curr = rq_selected(rq);
 	s64 delta_exec;
 
 	delta_exec = update_curr_se(rq, &curr->se);

@@ -1218,7 +1218,7 @@ static void update_curr(struct cfs_rq *cfs_rq)
 
 static void update_curr_fair(struct rq *rq)
 {
-	update_curr(cfs_rq_of(&rq->curr->se));
+	update_curr(cfs_rq_of(&rq_selected(rq)->se));
 }
 
 static inline void

@@ -6461,7 +6461,7 @@ static void hrtick_start_fair(struct rq *rq, struct task_struct *p)
 		s64 delta = slice - ran;
 
 		if (delta < 0) {
-			if (task_current(rq, p))
+			if (task_current_selected(rq, p))
 				resched_curr(rq);
 			return;
 		}

@@ -6476,7 +6476,7 @@ static void hrtick_start_fair(struct rq *rq, struct task_struct *p)
  */
 static void hrtick_update(struct rq *rq)
 {
-	struct task_struct *curr = rq->curr;
+	struct task_struct *curr = rq_selected(rq);
 
 	if (!hrtick_enabled_fair(rq) || curr->sched_class != &fair_sched_class)
 		return;

@@ -8082,7 +8082,7 @@ static void set_next_buddy(struct sched_entity *se)
  */
 static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_flags)
 {
-	struct task_struct *curr = rq->curr;
+	struct task_struct *curr = rq_selected(rq);
 	struct sched_entity *se = &curr->se, *pse = &p->se;
 	struct cfs_rq *cfs_rq = task_cfs_rq(curr);
 	int next_buddy_marked = 0;

@@ -8115,7 +8115,7 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_
 	 * prevents us from potentially nominating it as a false LAST_BUDDY
 	 * below.
 	 */
-	if (test_tsk_need_resched(curr))
+	if (test_tsk_need_resched(rq->curr))
 		return;
 
 	/* Idle tasks are by definition preempted by non-idle tasks. */

@@ -9099,7 +9099,7 @@ static bool __update_blocked_others(struct rq *rq, bool *done)
 	 * update_load_avg() can call cpufreq_update_util(). Make sure that RT,
 	 * DL and IRQ signals have been updated before updating CFS.
 	 */
-	curr_class = rq->curr->sched_class;
+	curr_class = rq_selected(rq)->sched_class;
 
 	thermal_pressure = arch_scale_thermal_pressure(cpu_of(rq));
 

@@ -12471,7 +12471,7 @@ prio_changed_fair(struct rq *rq, struct task_struct *p, int oldprio)
 	 * our priority decreased, or if we are not currently running on
 	 * this runqueue and our priority is higher than the current's
 	 */
-	if (task_current(rq, p)) {
+	if (task_current_selected(rq, p)) {
 		if (p->prio > oldprio)
 			resched_curr(rq);
 	} else

@@ -12574,7 +12574,7 @@ static void switched_to_fair(struct rq *rq, struct task_struct *p)
 		 * kick off the schedule if running, otherwise just see
 		 * if we can still preempt the current task.
 		 */
-		if (task_current(rq, p))
+		if (task_current_selected(rq, p))
 			resched_curr(rq);
 		else
 			check_preempt_curr(rq, p, 0);

index 327ae4148aec..bc243e70bc0e 100644
@@ -574,7 +574,7 @@ static void dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags)
 
 static void sched_rt_rq_enqueue(struct rt_rq *rt_rq)
 {
-	struct task_struct *curr = rq_of_rt_rq(rt_rq)->curr;
+	struct task_struct *curr = rq_selected(rq_of_rt_rq(rt_rq));
 	struct rq *rq = rq_of_rt_rq(rt_rq);
 	struct sched_rt_entity *rt_se;
 

@@ -1044,7 +1044,7 @@ static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq)
  */
 static void update_curr_rt(struct rq *rq)
 {
-	struct task_struct *curr = rq->curr;
+	struct task_struct *curr = rq_selected(rq);
 	struct sched_rt_entity *rt_se = &curr->rt;
 	s64 delta_exec;
 

@@ -1591,7 +1591,7 @@ static int find_lowest_rq(struct task_struct *task);
 static int
 select_task_rq_rt(struct task_struct *p, int cpu, int flags)
 {
-	struct task_struct *curr;
+	struct task_struct *curr, *selected;
 	struct rq *rq;
 	bool test;
 

@@ -1603,6 +1603,7 @@ select_task_rq_rt(struct task_struct *p, int cpu, int flags)
 
 	rcu_read_lock();
 	curr = READ_ONCE(rq->curr); /* unlocked access */
+	selected = READ_ONCE(rq_selected(rq));
 
 	/*
 	 * If the current task on @p's runqueue is an RT task, then

@@ -1631,8 +1632,8 @@ select_task_rq_rt(struct task_struct *p, int cpu, int flags)
 	 * systems like big.LITTLE.
 	 */
 	test = curr &&
-	       unlikely(rt_task(curr)) &&
-	       (curr->nr_cpus_allowed < 2 || curr->prio <= p->prio);
+	       unlikely(rt_task(selected)) &&
+	       (curr->nr_cpus_allowed < 2 || selected->prio <= p->prio);
 
 	if (test || !rt_task_fits_capacity(p, cpu)) {
 		int target = find_lowest_rq(p);

@@ -1662,12 +1663,8 @@ select_task_rq_rt(struct task_struct *p, int cpu, int flags)
 
 static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p)
 {
-	/*
-	 * Current can't be migrated, useless to reschedule,
-	 * let's hope p can move out.
-	 */
 	if (rq->curr->nr_cpus_allowed == 1 ||
-	    !cpupri_find(&rq->rd->cpupri, rq->curr, NULL))
+	    !cpupri_find(&rq->rd->cpupri, rq_selected(rq), NULL))
 		return;
 
 	/*

@@ -1710,7 +1707,9 @@ static int balance_rt(struct rq *rq, struct task_struct *p, struct rq_flags *rf)
  */
 static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int flags)
 {
-	if (p->prio < rq->curr->prio) {
+	struct task_struct *curr = rq_selected(rq);
+
+	if (p->prio < curr->prio) {
 		resched_curr(rq);
 		return;
 	}

@@ -1728,7 +1727,7 @@ static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int flag
 	 * to move current somewhere else, making room for our non-migratable
 	 * task.
 	 */
-	if (p->prio == rq->curr->prio && !test_tsk_need_resched(rq->curr))
+	if (p->prio == curr->prio && !test_tsk_need_resched(rq->curr))
 		check_preempt_equal_prio(rq, p);
 #endif
 }

@@ -1753,7 +1752,7 @@ static inline void set_next_task_rt(struct rq *rq, struct task_struct *p, bool f
 	 * utilization. We only care of the case where we start to schedule a
 	 * rt task
 	 */
-	if (rq->curr->sched_class != &rt_sched_class)
+	if (rq_selected(rq)->sched_class != &rt_sched_class)
 		update_rt_rq_load_avg(rq_clock_pelt(rq), rq, 0);
 
 	rt_queue_push_tasks(rq);

@@ -2034,6 +2033,7 @@ static struct task_struct *pick_next_pushable_task(struct rq *rq)
 
 	BUG_ON(rq->cpu != task_cpu(p));
 	BUG_ON(task_current(rq, p));
+	BUG_ON(task_current_selected(rq, p));
 	BUG_ON(p->nr_cpus_allowed <= 1);
 
 	BUG_ON(!task_on_rq_queued(p));

@@ -2066,7 +2066,7 @@ static int push_rt_task(struct rq *rq, bool pull)
 	 * higher priority than current. If that's the case
 	 * just reschedule current.
 	 */
-	if (unlikely(next_task->prio < rq->curr->prio)) {
+	if (unlikely(next_task->prio < rq_selected(rq)->prio)) {
 		resched_curr(rq);
 		return 0;
 	}

@@ -2419,7 +2419,7 @@ static void pull_rt_task(struct rq *this_rq)
 			 * p if it is lower in priority than the
 			 * current task on the run queue
 			 */
-			if (p->prio < src_rq->curr->prio)
+			if (p->prio < rq_selected(src_rq)->prio)
 				goto skip;
 
 			if (is_migration_disabled(p)) {

@@ -2461,9 +2461,9 @@ static void task_woken_rt(struct rq *rq, struct task_struct *p)
 	bool need_to_push = !task_on_cpu(rq, p) &&
 			    !test_tsk_need_resched(rq->curr) &&
 			    p->nr_cpus_allowed > 1 &&
-			    (dl_task(rq->curr) || rt_task(rq->curr)) &&
+			    (dl_task(rq_selected(rq)) || rt_task(rq_selected(rq))) &&
 			    (rq->curr->nr_cpus_allowed < 2 ||
-			     rq->curr->prio <= p->prio);
+			     rq_selected(rq)->prio <= p->prio);
 
 	if (need_to_push)
 		push_rt_tasks(rq);

@@ -2547,7 +2547,7 @@ static void switched_to_rt(struct rq *rq, struct task_struct *p)
 		if (p->nr_cpus_allowed > 1 && rq->rt.overloaded)
 			rt_queue_push_tasks(rq);
 #endif /* CONFIG_SMP */
-		if (p->prio < rq->curr->prio && cpu_online(cpu_of(rq)))
+		if (p->prio < rq_selected(rq)->prio && cpu_online(cpu_of(rq)))
 			resched_curr(rq);
 	}
 }

@@ -2562,7 +2562,7 @@ prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio)
 	if (!task_on_rq_queued(p))
 		return;
 
-	if (task_current(rq, p)) {
+	if (task_current_selected(rq, p)) {
 #ifdef CONFIG_SMP
 		/*
 		 * If our priority decreases while running, we

@@ -2588,7 +2588,7 @@ prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio)
 		 * greater than the current running task
 		 * then reschedule.
 		 */
-		if (p->prio < rq->curr->prio)
+		if (p->prio < rq_selected(rq)->prio)
 			resched_curr(rq);
 	}
 }

index 7c37d478e0f8..130e669cf5da 100644
@@ -1013,7 +1013,10 @@ struct rq {
 	 */
 	unsigned int		nr_uninterruptible;
 
-	struct task_struct __rcu	*curr;
+	struct task_struct __rcu	*curr;       /* Execution context */
+#ifdef CONFIG_PROXY_EXEC
+	struct task_struct __rcu	*curr_sched; /* Scheduling context (policy) */
+#endif
 	struct task_struct	*idle;
 	struct task_struct	*stop;
 	unsigned long		next_balance;

@@ -1212,6 +1215,22 @@ DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
 #define cpu_curr(cpu)		(cpu_rq(cpu)->curr)
 #define raw_rq()		raw_cpu_ptr(&runqueues)
 
+#ifdef CONFIG_PROXY_EXEC
+#define rq_selected(rq)		((rq)->curr_sched)
+#define cpu_curr_selected(cpu)	(cpu_rq(cpu)->curr_sched)
+static inline void rq_set_selected(struct rq *rq, struct task_struct *t)
+{
+	rcu_assign_pointer(rq->curr_sched, t);
+}
+#else
+#define rq_selected(rq)		((rq)->curr)
+#define cpu_curr_selected(cpu)	(cpu_rq(cpu)->curr)
+static inline void rq_set_selected(struct rq *rq, struct task_struct *t)
+{
+	/* Do nothing */
+}
+#endif
+
 struct sched_group;
 #ifdef CONFIG_SCHED_CORE
 static inline struct cpumask *sched_group_span(struct sched_group *sg);

@@ -2128,11 +2147,25 @@ static inline u64 global_rt_runtime(void)
 	return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC;
 }
 
+/*
+ * Is p the current execution context?
+ */
 static inline int task_current(struct rq *rq, struct task_struct *p)
 {
 	return rq->curr == p;
 }
 
+/*
+ * Is p the current scheduling context?
+ *
+ * Note that it might be the current execution context at the same time if
+ * rq->curr == rq_selected() == p.
+ */
+static inline int task_current_selected(struct rq *rq, struct task_struct *p)
+{
+	return rq_selected(rq) == p;
+}
+
 #ifdef CONFIG_PROXY_EXEC
 static inline bool task_is_blocked(struct task_struct *p)
 {

@@ -2308,7 +2341,7 @@ struct sched_class {
 
 static inline void put_prev_task(struct rq *rq, struct task_struct *prev)
 {
-	WARN_ON_ONCE(rq->curr != prev);
+	WARN_ON_ONCE(rq_selected(rq) != prev);
 	prev->sched_class->put_prev_task(rq, prev);
 }
 

index 3d5c1ec34bf7..1aca675985b2 100644
@@ -1144,22 +1144,36 @@ static void update_tg_load_avg(struct cfs_rq *cfs_rq)
 }
 #endif /* CONFIG_SMP */
 
-static s64 update_curr_se(struct rq *rq, struct sched_entity *curr)
+static s64 update_curr_se(struct rq *rq, struct sched_entity *se)
 {
 	u64 now = rq_clock_task(rq);
 	s64 delta_exec;
 
-	delta_exec = now - curr->exec_start;
+	/* Calculate the delta from selected se */
+	delta_exec = now - se->exec_start;
 	if (unlikely(delta_exec <= 0))
 		return delta_exec;
 
-	curr->exec_start = now;
-	curr->sum_exec_runtime += delta_exec;
+	/* Update selected se's exec_start */
+	se->exec_start = now;
+	if (entity_is_task(se)) {
+		struct task_struct *running = rq->curr;
+		/*
+		 * If se is a task, we account the time
+		 * against the running task, as w/ proxy-exec
+		 * they may not be the same.
+		 */
+		running->se.exec_start = now;
+		running->se.sum_exec_runtime += delta_exec;
+	} else {
+		/* If not task, account the time against se */
+		se->sum_exec_runtime += delta_exec;
+	}
 
 	if (schedstat_enabled()) {
 		struct sched_statistics *stats;
 
-		stats = __schedstats_from_se(curr);
+		stats = __schedstats_from_se(se);
 		__schedstat_set(stats->exec_max,
 				max(delta_exec, stats->exec_max));
 	}

index 9931940ba474..1b38b34d3f64 100644
@@ -6575,6 +6575,41 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
 # define SM_MASK_PREEMPT	SM_PREEMPT
 #endif
 
+static bool try_to_deactivate_task(struct rq *rq, struct task_struct *p, unsigned long state)
+{
+	if (signal_pending_state(state, p)) {
+		WRITE_ONCE(p->__state, TASK_RUNNING);
+	} else {
+		p->sched_contributes_to_load =
+			(state & TASK_UNINTERRUPTIBLE) &&
+			!(state & TASK_NOLOAD) &&
+			!(state & TASK_FROZEN);
+
+		if (p->sched_contributes_to_load)
+			rq->nr_uninterruptible++;
+
+		/*
+		 * __schedule()			ttwu()
+		 *   prev_state = prev->state;    if (p->on_rq && ...)
+		 *   if (prev_state)		    goto out;
+		 *     p->on_rq = 0;		  smp_acquire__after_ctrl_dep();
+		 *				  p->state = TASK_WAKING
+		 *
+		 * Where __schedule() and ttwu() have matching control dependencies.
+		 *
+		 * After this, schedule() must not care about p->state any more.
+		 */
+		deactivate_task(rq, p, DEQUEUE_SLEEP | DEQUEUE_NOCLOCK);
+
+		if (p->in_iowait) {
+			atomic_inc(&rq->nr_iowait);
+			delayacct_blkio_start();
+		}
+		return true;
+	}
+	return false;
+}
+
 /*
  * __schedule() is the main scheduler function.
  *

@@ -6665,35 +6700,7 @@ static void __sched notrace __schedule(unsigned int sched_mode)
 	 */
 	prev_state = READ_ONCE(prev->__state);
 	if (!(sched_mode & SM_MASK_PREEMPT) && prev_state) {
-		if (signal_pending_state(prev_state, prev)) {
-			WRITE_ONCE(prev->__state, TASK_RUNNING);
-		} else {
-			prev->sched_contributes_to_load =
-				(prev_state & TASK_UNINTERRUPTIBLE) &&
-				!(prev_state & TASK_NOLOAD) &&
-				!(prev_state & TASK_FROZEN);
-
-			if (prev->sched_contributes_to_load)
-				rq->nr_uninterruptible++;
-
-			/*
-			 * __schedule()			ttwu()
-			 *   prev_state = prev->state;    if (p->on_rq && ...)
-			 *   if (prev_state)		    goto out;
-			 *     p->on_rq = 0;		  smp_acquire__after_ctrl_dep();
-			 *				  p->state = TASK_WAKING
-			 *
-			 * Where __schedule() and ttwu() have matching control dependencies.
-			 *
-			 * After this, schedule() must not care about p->state any more.
-			 */
-			deactivate_task(rq, prev, DEQUEUE_SLEEP | DEQUEUE_NOCLOCK);
-
-			if (prev->in_iowait) {
-				atomic_inc(&rq->nr_iowait);
-				delayacct_blkio_start();
-			}
-		}
+		try_to_deactivate_task(rq, prev, prev_state);
 		switch_count = &prev->nvcsw;
 	}
 

index 1b38b34d3f64..5770656b898d 100644
@@ -6575,11 +6575,12 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
 # define SM_MASK_PREEMPT	SM_PREEMPT
 #endif
 
-static bool try_to_deactivate_task(struct rq *rq, struct task_struct *p, unsigned long state)
+static bool try_to_deactivate_task(struct rq *rq, struct task_struct *p,
+				   unsigned long state, bool deactivate_cond)
 {
 	if (signal_pending_state(state, p)) {
 		WRITE_ONCE(p->__state, TASK_RUNNING);
-	} else {
+	} else if (deactivate_cond) {
 		p->sched_contributes_to_load =
 			(state & TASK_UNINTERRUPTIBLE) &&
 			!(state & TASK_NOLOAD) &&

@@ -6610,6 +6611,74 @@ static bool try_to_deactivate_task(struct rq *rq, struct task_struct *p, unsigne
 	return false;
 }
 
+#ifdef CONFIG_PROXY_EXEC
+/*
+ * Initial simple proxy that just returns the task if its waking
+ * or deactivates the blocked task so we can pick something that
+ * isn't blocked.
+ */
+static struct task_struct *
+proxy(struct rq *rq, struct task_struct *next, struct rq_flags *rf)
+{
+	struct task_struct *p = next;
+	struct mutex *mutex;
+	unsigned long state;
+
+	mutex = p->blocked_on;
+	/* Something changed in the chain, pick_again */
+	if (!mutex)
+		return NULL;
+	/*
+	 * By taking mutex->wait_lock we hold off concurrent mutex_unlock()
+	 * and ensure @owner sticks around.
+	 */
+	raw_spin_lock(&mutex->wait_lock);
+	raw_spin_lock(&p->blocked_lock);
+
+	/* Check again that p is blocked with blocked_lock held */
+	if (!task_is_blocked(p) || mutex != p->blocked_on) {
+		/*
+		 * Something changed in the blocked_on chain and
+		 * we don't know if only at this level. So, let's
+		 * just bail out completely and let __schedule
+		 * figure things out (pick_again loop).
+		 */
+		raw_spin_unlock(&p->blocked_lock);
+		raw_spin_unlock(&mutex->wait_lock);
+		return NULL;
+	}
+
+	state = READ_ONCE(p->__state);
+	/* Don't deactivate if the state has been changed to TASK_RUNNING */
+	if (!state) {
+		raw_spin_unlock(&p->blocked_lock);
+		raw_spin_unlock(&mutex->wait_lock);
+		return p;
+	}
+
+	try_to_deactivate_task(rq, next, state, true);
+
+	/*
+	 * If next is the selected task, then remove lingering
+	 * references to it from rq and sched_class structs after
+	 * dequeueing.
+	 */
+	put_prev_task(rq, next);
+	rq_set_selected(rq, rq->idle);
+	resched_curr(rq);
+	raw_spin_unlock(&p->blocked_lock);
+	raw_spin_unlock(&mutex->wait_lock);
+	return NULL;
+}
+#else /* PROXY_EXEC */
+static struct task_struct *
+proxy(struct rq *rq, struct task_struct *next, struct rq_flags *rf)
+{
+	BUG(); // This should never be called in the !PROXY case
+	return next;
+}
+#endif /* PROXY_EXEC */
+
 /*
  * __schedule() is the main scheduler function.
  *

@@ -6700,12 +6769,24 @@ static void __sched notrace __schedule(unsigned int sched_mode)
 	 */
 	prev_state = READ_ONCE(prev->__state);
 	if (!(sched_mode & SM_MASK_PREEMPT) && prev_state) {
-		try_to_deactivate_task(rq, prev, prev_state);
+		try_to_deactivate_task(rq, prev, prev_state,
+				       !task_is_blocked(prev));
 		switch_count = &prev->nvcsw;
 	}
 
-	next = pick_next_task(rq, prev, &rf);
+pick_again:
+	next = pick_next_task(rq, rq_selected(rq), &rf);
 	rq_set_selected(rq, next);
+	if (unlikely(task_is_blocked(next))) {
+		next = proxy(rq, next, &rf);
+		if (!next) {
+			rq_unpin_lock(rq, &rf);
+			__balance_callbacks(rq);
+			rq_repin_lock(rq, &rf);
+			goto pick_again;
+		}
+	}
+
 	clear_tsk_need_resched(prev);
 	clear_preempt_need_resched();
 #ifdef CONFIG_SCHED_DEBUG

index bc243e70bc0e..0125a3ae5a7a 100644
@@ -1537,8 +1537,19 @@ enqueue_task_rt(struct rq *rq, struct task_struct *p, int flags)
 
 	enqueue_rt_entity(rt_se, flags);
 
-	if (!task_current(rq, p) && p->nr_cpus_allowed > 1)
-		enqueue_pushable_task(rq, p);
+	/*
+	 * Current can't be pushed away. Selected is tied to current,
+	 * so don't push it either.
+	 */
+	if (task_current(rq, p) || task_current_selected(rq, p))
+		return;
+	/*
+	 * Pinned tasks can't be pushed.
+	 */
+	if (p->nr_cpus_allowed == 1)
+		return;
+
+	enqueue_pushable_task(rq, p);
 }
 
 static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags)