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

From: shangxiaojing
Date: Fri Aug 26 2022 - 03:40:14 EST



On 2022/8/26 15:15, Daniel Bristot de Oliveira wrote:
On 8/26/22 05:15, Shang XiaoJing wrote:
Wrap repeated code in helper function start_new_instance, which set
the deadline and runtiem of input dl_se based on pi_of(dl_se). Note that
^ runtime
oops
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@xxxxxxxxxx>
---
kernel/sched/deadline.c | 22 ++++++++++++----------
1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 4a40a462717c..5e9c28847610 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -770,6 +770,13 @@ 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);
again, this is not a good function name. Maybe, dl_replenish_new_period() ?

right, i have thought like replenish_new_instance, but when i'm making patch,  i was worried that "replenish" is only for ENQUEUE_REPLENISH.

what about dl_start_new_period? which means a new deadline will be set, rather than

    dl_se->deadline += pi_of(dl_se)->dl_period;

in replenish_dl_entity.

+static inline void start_new_instance(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;
+}
+
-- Daniel

Thanks,

Shang XiaoJing