[PATCH -next v2] sched/deadline: Add replenish_dl_new_period helper

[PATCH -next v2] sched/deadline: Add replenish_dl_new_period helper

[Shang XiaoJing]

Wrap repeated code in helper function replenish_dl_new_period, which set
the deadline and runtime of input dl_se based on pi_of(dl_se). Note that
setup_new_dl_entity originally set the deadline and runtime base on
dl_se, which should equals to pi_of(dl_se) for non-boosted task.

Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
---
changes in v2:
- fix comment msg
- pick a more descriptive function name rather than start_new_instance.
---
 kernel/sched/deadline.c | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 34271aff4712..3bf4b12ec5b7 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -770,6 +770,14 @@ static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags);
 static void __dequeue_task_dl(struct rq *rq, struct task_struct *p, int flags);
 static void check_preempt_curr_dl(struct rq *rq, struct task_struct *p, int flags);
 
+static inline void replenish_dl_new_period(struct sched_dl_entity *dl_se,
+					    struct rq *rq)
+{
+	/* for non-boosted task, pi_of(dl_se) == dl_se */
+	dl_se->deadline = rq_clock(rq) + pi_of(dl_se)->dl_deadline;
+	dl_se->runtime = pi_of(dl_se)->dl_runtime;
+}
+
 /*
  * We are being explicitly informed that a new instance is starting,
  * and this means that:
@@ -803,8 +811,7 @@ static inline void setup_new_dl_entity(struct sched_dl_entity *dl_se)
 	 * future; in fact, we must consider execution overheads (time
 	 * spent on hardirq context, etc.).
 	 */
-	dl_se->deadline = rq_clock(rq) + dl_se->dl_deadline;
-	dl_se->runtime = dl_se->dl_runtime;
+	replenish_dl_new_period(dl_se, rq);
 }
 
 /*
@@ -836,10 +843,8 @@ static void replenish_dl_entity(struct sched_dl_entity *dl_se)
 	 * This could be the case for a !-dl task that is boosted.
 	 * Just go with full inherited parameters.
 	 */
-	if (dl_se->dl_deadline == 0) {
-		dl_se->deadline = rq_clock(rq) + pi_of(dl_se)->dl_deadline;
-		dl_se->runtime = pi_of(dl_se)->dl_runtime;
-	}
+	if (dl_se->dl_deadline == 0)
+		replenish_dl_new_period(dl_se, rq);
 
 	if (dl_se->dl_yielded && dl_se->runtime > 0)
 		dl_se->runtime = 0;
@@ -866,8 +871,7 @@ static void replenish_dl_entity(struct sched_dl_entity *dl_se)
 	 */
 	if (dl_time_before(dl_se->deadline, rq_clock(rq))) {
 		printk_deferred_once("sched: DL replenish lagged too much\n");
-		dl_se->deadline = rq_clock(rq) + pi_of(dl_se)->dl_deadline;
-		dl_se->runtime = pi_of(dl_se)->dl_runtime;
+		replenish_dl_new_period(dl_se, rq);
 	}
 
 	if (dl_se->dl_yielded)
@@ -1024,8 +1028,7 @@ static void update_dl_entity(struct sched_dl_entity *dl_se)
 			return;
 		}
 
-		dl_se->deadline = rq_clock(rq) + pi_of(dl_se)->dl_deadline;
-		dl_se->runtime = pi_of(dl_se)->dl_runtime;
+		replenish_dl_new_period(dl_se, rq);
 	}
 }
 
-- 
2.17.1

Re: [PATCH -next v2] sched/deadline: Add replenish_dl_new_period helper

[Daniel Bristot de Oliveira]

On 8/26/22 12:00, Shang XiaoJing wrote:
> Wrap repeated code in helper function replenish_dl_new_period, which set
> the deadline and runtime of input dl_se based on pi_of(dl_se). Note that
> setup_new_dl_entity originally set the deadline and runtime base on
> dl_se, which should equals to pi_of(dl_se) for non-boosted task.
> 
> Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>

Reviewed-by: Daniel Bristot de Oliveira <bristot@kernel.org>

-- Daniel

[tip: sched/core] sched/deadline: Add replenish_dl_new_period helper

[tip-bot2 for Shang XiaoJing]

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     96458e7f7dc5ad14bd7577cbf1638e1504ad79dd
Gitweb:        https://git.kernel.org/tip/96458e7f7dc5ad14bd7577cbf1638e1504ad79dd
Author:        Shang XiaoJing <shangxiaojing@huawei.com>
AuthorDate:    Fri, 26 Aug 2022 18:00:37 +08:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Thu, 01 Sep 2022 11:19:54 +02:00

sched/deadline: Add replenish_dl_new_period helper

Wrap repeated code in helper function replenish_dl_new_period, which set
the deadline and runtime of input dl_se based on pi_of(dl_se). Note that
setup_new_dl_entity originally set the deadline and runtime base on
dl_se, which should equals to pi_of(dl_se) for non-boosted task.

Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Link: https://lore.kernel.org/r/20220826100037.12146-1-shangxiaojing@huawei.com
---
 kernel/sched/deadline.c | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 34271af..3bf4b12 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -770,6 +770,14 @@ static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags);
 static void __dequeue_task_dl(struct rq *rq, struct task_struct *p, int flags);
 static void check_preempt_curr_dl(struct rq *rq, struct task_struct *p, int flags);
 
+static inline void replenish_dl_new_period(struct sched_dl_entity *dl_se,
+					    struct rq *rq)
+{
+	/* for non-boosted task, pi_of(dl_se) == dl_se */
+	dl_se->deadline = rq_clock(rq) + pi_of(dl_se)->dl_deadline;
+	dl_se->runtime = pi_of(dl_se)->dl_runtime;
+}
+
 /*
  * We are being explicitly informed that a new instance is starting,
  * and this means that:
@@ -803,8 +811,7 @@ static inline void setup_new_dl_entity(struct sched_dl_entity *dl_se)
 	 * future; in fact, we must consider execution overheads (time
 	 * spent on hardirq context, etc.).
 	 */
-	dl_se->deadline = rq_clock(rq) + dl_se->dl_deadline;
-	dl_se->runtime = dl_se->dl_runtime;
+	replenish_dl_new_period(dl_se, rq);
 }
 
 /*
@@ -836,10 +843,8 @@ static void replenish_dl_entity(struct sched_dl_entity *dl_se)
 	 * This could be the case for a !-dl task that is boosted.
 	 * Just go with full inherited parameters.
 	 */
-	if (dl_se->dl_deadline == 0) {
-		dl_se->deadline = rq_clock(rq) + pi_of(dl_se)->dl_deadline;
-		dl_se->runtime = pi_of(dl_se)->dl_runtime;
-	}
+	if (dl_se->dl_deadline == 0)
+		replenish_dl_new_period(dl_se, rq);
 
 	if (dl_se->dl_yielded && dl_se->runtime > 0)
 		dl_se->runtime = 0;
@@ -866,8 +871,7 @@ static void replenish_dl_entity(struct sched_dl_entity *dl_se)
 	 */
 	if (dl_time_before(dl_se->deadline, rq_clock(rq))) {
 		printk_deferred_once("sched: DL replenish lagged too much\n");
-		dl_se->deadline = rq_clock(rq) + pi_of(dl_se)->dl_deadline;
-		dl_se->runtime = pi_of(dl_se)->dl_runtime;
+		replenish_dl_new_period(dl_se, rq);
 	}
 
 	if (dl_se->dl_yielded)
@@ -1024,8 +1028,7 @@ static void update_dl_entity(struct sched_dl_entity *dl_se)
 			return;
 		}
 
-		dl_se->deadline = rq_clock(rq) + pi_of(dl_se)->dl_deadline;
-		dl_se->runtime = pi_of(dl_se)->dl_runtime;
+		replenish_dl_new_period(dl_se, rq);
 	}
 }