[RFC PATCH v3 21/24] sched/deadline: Make rt-cgroup's servers pull tasks on timer replenishment

[Yuri Andriaccio <yurand2000@gmail.com>]

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

Signed-off-by: luca abeni <luca.abeni@santannapisa.it>
Signed-off-by: Yuri Andriaccio <yurand2000@gmail.com>
---
 kernel/sched/deadline.c | 6 +++++-
 kernel/sched/rt.c       | 6 +++++-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index abe11985c41..27a5d5ffd39 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -1290,6 +1290,7 @@ static enum hrtimer_restart dl_server_timer(struct hrtimer *timer, struct sched_
 {
 	struct rq *rq = rq_of_dl_se(dl_se);
 	u64 fw;
+	bool has_tasks;
 
 	scoped_guard (rq_lock, rq) {
 		struct rq_flags *rf = &scope.rf;
@@ -1303,7 +1304,10 @@ static enum hrtimer_restart dl_server_timer(struct hrtimer *timer, struct sched_
 		if (!dl_se->dl_runtime)
 			return HRTIMER_NORESTART;
 
-		if (!dl_se->server_has_tasks(dl_se)) {
+		rq_unpin_lock(rq, rf);
+		has_tasks = dl_se->server_has_tasks(dl_se);
+		rq_repin_lock(rq, rf);
+		if (!has_tasks) {
 			replenish_dl_entity(dl_se);
 			dl_server_stopped(dl_se);
 			return HRTIMER_NORESTART;
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index a864f569011..b09f0887e3b 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -1,4 +1,3 @@
-#pragma GCC diagnostic ignored "-Wunused-function"
 // SPDX-License-Identifier: GPL-2.0
 /*
  * Real-Time Scheduling Class (mapped to the SCHED_FIFO and SCHED_RR
@@ -153,6 +152,11 @@ static inline void set_next_task_rt(struct rq *rq, struct task_struct *p, bool f
 
 static bool rt_server_has_tasks(struct sched_dl_entity *dl_se)
 {
+#ifdef CONFIG_SMP
+	struct rt_rq *rt_rq = &dl_se->my_q->rt;
+
+	group_pull_rt_task(rt_rq);
+#endif
 	return !!dl_se->my_q->rt.rt_nr_running;
 }
 
-- 
2.51.0