From ff1cdc94de4d336be45336d70709dfcf3d682514 Mon Sep 17 00:00:00 2001 From: Muchun Song Date: Fri, 26 Oct 2018 21:17:43 +0800 Subject: sched/core: Introduce set_next_task() helper for better code readability When we pick the next task, we will do the following for the task: 1) p->se.exec_start = rq_clock_task(rq); 2) dequeue_pushable(_dl)_task(rq, p); When we call set_curr_task(), we also need to do the same thing above. In rt.c, the code at 1) is in the _pick_next_task_rt() and the code at 2) is in the pick_next_task_rt(). If we put two operations in one function, maybe better. So, we introduce a new function set_next_task(), which is responsible for doing the above. By introducing the function we can get rid of calling the dequeue_pushable(_dl)_task() directly(We can call set_next_task()) in pick_next_task() and have better code readability and reuse. In set_curr_task_rt(), we also can call set_next_task(). Do this things such that we end up with: static struct task_struct *pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) { /* do something else ... */ put_prev_task(rq, prev); /* pick next task p */ set_next_task(rq, p); /* do something else ... */ } put_prev_task() can match set_next_task(), which can make the code more readable. Signed-off-by: Muchun Song Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20181026131743.21786-1-smuchun@gmail.com Signed-off-by: Ingo Molnar --- kernel/sched/deadline.c | 19 ++++++++++--------- kernel/sched/rt.c | 24 +++++++++++------------- 2 files changed, 21 insertions(+), 22 deletions(-) (limited to 'kernel') diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 91e4202b0634..470ba6b464fe 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1695,6 +1695,14 @@ static void start_hrtick_dl(struct rq *rq, struct task_struct *p) } #endif +static inline void set_next_task(struct rq *rq, struct task_struct *p) +{ + p->se.exec_start = rq_clock_task(rq); + + /* You can't push away the running task */ + dequeue_pushable_dl_task(rq, p); +} + static struct sched_dl_entity *pick_next_dl_entity(struct rq *rq, struct dl_rq *dl_rq) { @@ -1750,10 +1758,8 @@ pick_next_task_dl(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) BUG_ON(!dl_se); p = dl_task_of(dl_se); - p->se.exec_start = rq_clock_task(rq); - /* Running task will never be pushed. */ - dequeue_pushable_dl_task(rq, p); + set_next_task(rq, p); if (hrtick_enabled(rq)) start_hrtick_dl(rq, p); @@ -1808,12 +1814,7 @@ static void task_fork_dl(struct task_struct *p) static void set_curr_task_dl(struct rq *rq) { - struct task_struct *p = rq->curr; - - p->se.exec_start = rq_clock_task(rq); - - /* You can't push away the running task */ - dequeue_pushable_dl_task(rq, p); + set_next_task(rq, rq->curr); } #ifdef CONFIG_SMP diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index a21ea6021929..9aa3287ce301 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -1498,6 +1498,14 @@ static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int flag #endif } +static inline void set_next_task(struct rq *rq, struct task_struct *p) +{ + p->se.exec_start = rq_clock_task(rq); + + /* The running task is never eligible for pushing */ + dequeue_pushable_task(rq, p); +} + static struct sched_rt_entity *pick_next_rt_entity(struct rq *rq, struct rt_rq *rt_rq) { @@ -1518,7 +1526,6 @@ static struct sched_rt_entity *pick_next_rt_entity(struct rq *rq, static struct task_struct *_pick_next_task_rt(struct rq *rq) { struct sched_rt_entity *rt_se; - struct task_struct *p; struct rt_rq *rt_rq = &rq->rt; do { @@ -1527,10 +1534,7 @@ static struct task_struct *_pick_next_task_rt(struct rq *rq) rt_rq = group_rt_rq(rt_se); } while (rt_rq); - p = rt_task_of(rt_se); - p->se.exec_start = rq_clock_task(rq); - - return p; + return rt_task_of(rt_se); } static struct task_struct * @@ -1573,8 +1577,7 @@ pick_next_task_rt(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) p = _pick_next_task_rt(rq); - /* The running task is never eligible for pushing */ - dequeue_pushable_task(rq, p); + set_next_task(rq, p); rt_queue_push_tasks(rq); @@ -2355,12 +2358,7 @@ static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued) static void set_curr_task_rt(struct rq *rq) { - struct task_struct *p = rq->curr; - - p->se.exec_start = rq_clock_task(rq); - - /* The running task is never eligible for pushing */ - dequeue_pushable_task(rq, p); + set_next_task(rq, rq->curr); } static unsigned int get_rr_interval_rt(struct rq *rq, struct task_struct *task) -- cgit v1.2.3