linux-kernel - [PATCH -next v2] sched/deadline: Add replenish_dl_new

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Message-ID: <20220826100037.12146-1-shangxiaojing@huawei.com>
Date:   Fri, 26 Aug 2022 18:00:37 +0800
From:   Shang XiaoJing <shangxiaojing@...wei.com>
To:     <mingo@...hat.com>, <peterz@...radead.org>,
        <juri.lelli@...hat.com>, <vincent.guittot@...aro.org>,
        <dietmar.eggemann@....com>, <rostedt@...dmis.org>,
        <bsegall@...gle.com>, <mgorman@...e.de>, <bristot@...hat.com>,
        <vschneid@...hat.com>, <linux-kernel@...r.kernel.org>
CC:     <shangxiaojing@...wei.com>
Subject: [PATCH -next v2] 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@...wei.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