[RFC PATCH v7 02/29] sched/deadline: Do not access dl_se->rq directly

[Yuri Andriaccio <yurand2000@gmail.com>]

From: luca abeni <luca.abeni@santannapisa.it>

Make deadline.c code access the runqueue of a scheduling entity saved in
the sched_dl_entity data structure. This allows future patches to save
different runqueues in sched_dl_entity other than the global runqueues.

Move dl_server_apply_params call in sched_init_dl_servers as the rq_of_dl_se
function will return the correct deadline entity only if the dl_server flag
is set.

Add a WARN_ON on the return value of dl_server_apply_params in
sched_init_dl_servers as this function may fail if the kernel is not
configured correctly.

Signed-off-by: luca abeni <luca.abeni@santannapisa.it>
Signed-off-by: Yuri Andriaccio <yurand2000@gmail.com>
---
 kernel/sched/deadline.c | 46 ++++++++++++++++++++---------------------
 1 file changed, 23 insertions(+), 23 deletions(-)

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 57c7a8802d8e..00f584c7bbd5 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -869,7 +869,7 @@ static void replenish_dl_entity(struct sched_dl_entity *dl_se)
 	 * and arm the defer timer.
 	 */
 	if (dl_se->dl_defer && !dl_se->dl_defer_running &&
-	    dl_time_before(rq_clock(dl_se->rq), dl_se->deadline - dl_se->runtime)) {
+	    dl_time_before(rq_clock(rq), dl_se->deadline - dl_se->runtime)) {
 		if (!is_dl_boosted(dl_se)) {
 
 			/*
@@ -1171,11 +1171,11 @@ static enum hrtimer_restart dl_server_timer(struct hrtimer *timer, struct sched_
 			 * of time. The dl_server_min_res serves as a limit to avoid
 			 * forwarding the timer for a too small amount of time.
 			 */
-			if (dl_time_before(rq_clock(dl_se->rq),
+			if (dl_time_before(rq_clock(rq),
 					   (dl_se->deadline - dl_se->runtime - dl_server_min_res))) {
 
 				/* reset the defer timer */
-				fw = dl_se->deadline - rq_clock(dl_se->rq) - dl_se->runtime;
+				fw = dl_se->deadline - rq_clock(rq) - dl_se->runtime;
 
 				hrtimer_forward_now(timer, ns_to_ktime(fw));
 				return HRTIMER_RESTART;
@@ -1186,7 +1186,7 @@ static enum hrtimer_restart dl_server_timer(struct hrtimer *timer, struct sched_
 
 		enqueue_dl_entity(dl_se, ENQUEUE_REPLENISH);
 
-		if (!dl_task(dl_se->rq->curr) || dl_entity_preempt(dl_se, &dl_se->rq->curr->dl))
+		if (!dl_task(rq->curr) || dl_entity_preempt(dl_se, &rq->curr->dl))
 			resched_curr(rq);
 
 		__push_dl_task(rq, rf);
@@ -1482,7 +1482,7 @@ static void update_curr_dl_se(struct rq *rq, struct sched_dl_entity *dl_se, s64
 
 		hrtimer_try_to_cancel(&dl_se->dl_timer);
 
-		replenish_dl_new_period(dl_se, dl_se->rq);
+		replenish_dl_new_period(dl_se, rq);
 
 		if (idle)
 			dl_se->dl_defer_idle = 1;
@@ -1579,14 +1579,14 @@ static void update_curr_dl_se(struct rq *rq, struct sched_dl_entity *dl_se, s64
 void dl_server_update_idle(struct sched_dl_entity *dl_se, s64 delta_exec)
 {
 	if (dl_se->dl_server_active && dl_se->dl_runtime && dl_se->dl_defer)
-		update_curr_dl_se(dl_se->rq, dl_se, delta_exec);
+		update_curr_dl_se(rq_of_dl_se(dl_se), dl_se, delta_exec);
 }
 
 void dl_server_update(struct sched_dl_entity *dl_se, s64 delta_exec)
 {
 	/* 0 runtime = fair server disabled */
 	if (dl_se->dl_server_active && dl_se->dl_runtime)
-		update_curr_dl_se(dl_se->rq, dl_se, delta_exec);
+		update_curr_dl_se(rq_of_dl_se(dl_se), dl_se, delta_exec);
 }
 
 /*
@@ -1795,7 +1795,7 @@ void dl_server_update(struct sched_dl_entity *dl_se, s64 delta_exec)
  */
 void dl_server_start(struct sched_dl_entity *dl_se)
 {
-	struct rq *rq = dl_se->rq;
+	struct rq *rq;
 
 	dl_se->dl_defer_idle = 0;
 	if (!dl_server(dl_se) || dl_se->dl_server_active || !dl_se->dl_runtime ||
@@ -1805,16 +1805,16 @@ void dl_server_start(struct sched_dl_entity *dl_se)
 	/*
 	 * Update the current task to 'now'.
 	 */
+	rq = rq_of_dl_se(dl_se);
 	rq->donor->sched_class->update_curr(rq);
-
 	if (WARN_ON_ONCE(!cpu_online(cpu_of(rq))))
 		return;
 
 	trace_sched_dl_server_start_tp(dl_se, cpu_of(rq), dl_get_type(dl_se, rq));
 	dl_se->dl_server_active = 1;
 	enqueue_dl_entity(dl_se, ENQUEUE_WAKEUP);
-	if (!dl_task(dl_se->rq->curr) || dl_entity_preempt(dl_se, &rq->curr->dl))
-		resched_curr(dl_se->rq);
+	if (!dl_task(rq->curr) || dl_entity_preempt(dl_se, &rq->curr->dl))
+		resched_curr(rq);
 }
 
 void dl_server_stop(struct sched_dl_entity *dl_se)
@@ -1858,9 +1858,9 @@ void sched_init_dl_servers(void)
 
 		WARN_ON(dl_server(dl_se));
 
-		dl_server_apply_params(dl_se, runtime, period, 1);
-
 		dl_se->dl_server = 1;
+		WARN_ON(dl_server_apply_params(dl_se, runtime, period, 1));
+
 		dl_se->dl_defer = 1;
 		dl_se->dl_freq_invariant = 1;
 		setup_new_dl_entity(dl_se);
@@ -1870,9 +1870,9 @@ void sched_init_dl_servers(void)
 
 		WARN_ON(dl_server(dl_se));
 
-		dl_server_apply_params(dl_se, runtime, period, 1);
-
 		dl_se->dl_server = 1;
+		WARN_ON(dl_server_apply_params(dl_se, runtime, period, 1));
+
 		dl_se->dl_defer = 1;
 		dl_se->dl_freq_invariant = 1;
 		setup_new_dl_entity(dl_se);
@@ -1910,7 +1910,7 @@ int dl_server_apply_params(struct sched_dl_entity *dl_se, u64 runtime, u64 perio
 	u64 old_bw = (init || !dl_se->dl_bw_attached) ? 0 :
 		     to_ratio(dl_se->dl_period, dl_se->dl_runtime);
 	u64 new_bw = to_ratio(period, runtime);
-	struct rq *rq = dl_se->rq;
+	struct rq *rq = rq_of_dl_se(dl_se);
 	int cpu = cpu_of(rq);
 	struct dl_bw *dl_b;
 	unsigned long cap;
@@ -1957,7 +1957,7 @@ int dl_server_apply_params(struct sched_dl_entity *dl_se, u64 runtime, u64 perio
 static int __dl_server_attach_bw_locked(struct sched_dl_entity *dl_se,
 					struct dl_bw *dl_b, int cpus)
 {
-	struct rq *rq = dl_se->rq;
+	struct rq *rq = rq_of_dl_se(dl_se);
 	unsigned long cap;
 
 	/*
@@ -1985,7 +1985,7 @@ static int __dl_server_attach_bw_locked(struct sched_dl_entity *dl_se,
 static void __dl_server_detach_bw_locked(struct sched_dl_entity *dl_se,
 					 struct dl_bw *dl_b, int cpus)
 {
-	struct rq *rq = dl_se->rq;
+	struct rq *rq = rq_of_dl_se(dl_se);
 
 	/*
 	 * If the server is still active (on_rq), dequeue it via
@@ -2030,7 +2030,7 @@ static void __dl_server_detach_bw_locked(struct sched_dl_entity *dl_se,
  */
 int dl_server_attach_bw(struct sched_dl_entity *dl_se)
 {
-	struct rq *rq = dl_se->rq;
+	struct rq *rq = rq_of_dl_se(dl_se);
 	int cpu = cpu_of(rq);
 	struct dl_bw *dl_b;
 	int cpus, ret;
@@ -2071,7 +2071,7 @@ int dl_server_attach_bw(struct sched_dl_entity *dl_se)
  */
 void dl_server_detach_bw(struct sched_dl_entity *dl_se)
 {
-	int cpu = cpu_of(dl_se->rq);
+	int cpu = cpu_of(rq_of_dl_se(dl_se));
 	struct dl_bw *dl_b;
 	int cpus;
 
@@ -2096,12 +2096,12 @@ void dl_server_detach_bw(struct sched_dl_entity *dl_se)
 int dl_server_swap_bw(struct sched_dl_entity *detach_se,
 		      struct sched_dl_entity *attach_se)
 {
-	struct rq *rq = detach_se->rq;
+	struct rq *rq = rq_of_dl_se(detach_se);
 	int cpu = cpu_of(rq);
 	struct dl_bw *dl_b;
 	int cpus, ret;
 
-	WARN_ON_ONCE(attach_se->rq != rq);
+	WARN_ON_ONCE(rq_of_dl_se(attach_se) != rq);
 
 	scoped_guard (raw_spinlock, &dl_bw_of(cpu)->lock) {
 		dl_b = dl_bw_of(cpu);
@@ -2162,7 +2162,7 @@ static enum hrtimer_restart inactive_task_timer(struct hrtimer *timer)
 		p = dl_task_of(dl_se);
 		rq = task_rq_lock(p, &rf);
 	} else {
-		rq = dl_se->rq;
+		rq = rq_of_dl_se(dl_se);
 		rq_lock(rq, &rf);
 	}
 
-- 
2.56.0