[RFC PATCH v4 07/28] sched/rt: Introduce HCBS specific structs in task_group

[Yuri Andriaccio <yurand2000@gmail.com>]

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

Each task_group manages a number of new objects:
- a sched_dl_entity/dl_server for each CPU
- a dl_bandwidth object to keep track of its allocated dl_bandwidth

Co-developed-by: Alessio Balsini <a.balsini@sssup.it>
Signed-off-by: Alessio Balsini <a.balsini@sssup.it>
Co-developed-by: Andrea Parri <parri.andrea@gmail.com>
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
Co-developed-by: Yuri Andriaccio <yurand2000@gmail.com>
Signed-off-by: Yuri Andriaccio <yurand2000@gmail.com>
Signed-off-by: luca abeni <luca.abeni@santannapisa.it>
---
 kernel/sched/sched.h | 22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 1896c4e247..75a3dc475b 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -319,6 +319,13 @@ struct rt_bandwidth {
 	unsigned int		rt_period_active;
 };

+struct dl_bandwidth {
+	raw_spinlock_t          dl_runtime_lock;
+	u64                     dl_runtime;
+	u64                     dl_period;
+};
+
+
 static inline int dl_bandwidth_enabled(void)
 {
 	return sysctl_sched_rt_runtime >= 0;
@@ -492,10 +499,17 @@ struct task_group {
 #endif /* CONFIG_FAIR_GROUP_SCHED */

 #ifdef CONFIG_RT_GROUP_SCHED
+	/*
+	 * Each task group manages a different scheduling entity per CPU, i.e. a
+	 * different deadline server, and a runqueue per CPU. All the dl-servers
+	 * share the same dl_bandwidth object.
+	 */
 	struct sched_rt_entity	**rt_se;
+	struct sched_dl_entity	**dl_se;
 	struct rt_rq		**rt_rq;

 	struct rt_bandwidth	rt_bandwidth;
+	struct dl_bandwidth	dl_bandwidth;
 #endif

 	struct scx_task_group	scx;
@@ -845,12 +859,16 @@ struct rt_rq {
 	raw_spinlock_t		rt_runtime_lock;

 	unsigned int		rt_nr_boosted;
-
-	struct rq		*rq; /* this is always top-level rq, cache? */
 #endif
 #ifdef CONFIG_CGROUP_SCHED
 	struct task_group	*tg; /* this tg has "this" rt_rq on given CPU for runnable entities */
 #endif
+
+	/*
+	 * The cgroup's served runqueue if the rt_rq entity belongs to a cgroup,
+	 * otherwise the top-level global runqueue.
+	 */
+	struct rq		*rq;
 };

 static inline bool rt_rq_is_runnable(struct rt_rq *rt_rq)
--
2.51.0