Commit 4686cc59 authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

sched: Clean up DL server vs core sched 



Abide by the simple rule:

  pick_next_task() := pick_task() + set_next_task(.first = true)

This allows us to trivially get rid of server_pick_next() and things
collapse nicely.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240813224015.837303391@infradead.org
parent dae4320b

include/linux/sched.h

+0 −1
Original line number Diff line number Diff line
@@ -692,7 +692,6 @@ struct sched_dl_entity { 
	 */

	struct rq			*rq;

	dl_server_has_tasks_f		server_has_tasks;

	dl_server_pick_f		server_pick_next;

	dl_server_pick_f		server_pick_task;



#ifdef CONFIG_RT_MUTEXES

kernel/sched/deadline.c

+7 −11
Original line number Diff line number Diff line
@@ -1665,12 +1665,10 @@ void dl_server_stop(struct sched_dl_entity *dl_se) 


void dl_server_init(struct sched_dl_entity *dl_se, struct rq *rq,

		    dl_server_has_tasks_f has_tasks,

		    dl_server_pick_f pick_next,

		    dl_server_pick_f pick_task)

{

	dl_se->rq = rq;

	dl_se->server_has_tasks = has_tasks;

	dl_se->server_pick_next = pick_next;

	dl_se->server_pick_task = pick_task;

}
@@ -2404,9 +2402,8 @@ static struct sched_dl_entity *pick_next_dl_entity(struct dl_rq *dl_rq) 
/*

 * __pick_next_task_dl - Helper to pick the next -deadline task to run.

 * @rq: The runqueue to pick the next task from.

 * @peek: If true, just peek at the next task. Only relevant for dlserver.

 */

static struct task_struct *__pick_next_task_dl(struct rq *rq, bool peek)

static struct task_struct *__pick_task_dl(struct rq *rq)

{

	struct sched_dl_entity *dl_se;

	struct dl_rq *dl_rq = &rq->dl;
@@ -2420,10 +2417,7 @@ static struct task_struct *__pick_next_task_dl(struct rq *rq, bool peek) 
	WARN_ON_ONCE(!dl_se);



	if (dl_server(dl_se)) {

		if (IS_ENABLED(CONFIG_SMP) && peek)

		p = dl_se->server_pick_task(dl_se);

		else

			p = dl_se->server_pick_next(dl_se);

		if (!p) {

			dl_se->dl_yielded = 1;

			update_curr_dl_se(rq, dl_se, 0);
@@ -2440,7 +2434,7 @@ static struct task_struct *__pick_next_task_dl(struct rq *rq, bool peek) 
#ifdef CONFIG_SMP

static struct task_struct *pick_task_dl(struct rq *rq)

{

	return __pick_next_task_dl(rq, true);

	return __pick_task_dl(rq);

}

#endif
@@ -2448,11 +2442,13 @@ static struct task_struct *pick_next_task_dl(struct rq *rq) 
{

	struct task_struct *p;



	p = __pick_next_task_dl(rq, false);

	p = __pick_task_dl(rq);

	if (!p)

		return p;



	if (!p->dl_server)

	if (p->dl_server)

		p->sched_class->set_next_task(rq, p, true);

	else

		set_next_task_dl(rq, p, true);



	return p;

kernel/sched/fair.c

+1 −12
Original line number Diff line number Diff line
@@ -8862,16 +8862,7 @@ static bool fair_server_has_tasks(struct sched_dl_entity *dl_se) 


static struct task_struct *fair_server_pick_task(struct sched_dl_entity *dl_se)

{

#ifdef CONFIG_SMP

	return pick_task_fair(dl_se->rq);

#else

	return NULL;

#endif

}



static struct task_struct *fair_server_pick_next(struct sched_dl_entity *dl_se)

{

	return pick_next_task_fair(dl_se->rq, NULL, NULL);

}



void fair_server_init(struct rq *rq)
@@ -8880,9 +8871,7 @@ void fair_server_init(struct rq *rq) 


	init_dl_entity(dl_se);



	dl_server_init(dl_se, rq, fair_server_has_tasks, fair_server_pick_next,

		       fair_server_pick_task);



	dl_server_init(dl_se, rq, fair_server_has_tasks, fair_server_pick_task);

}



/*

kernel/sched/sched.h

+0 −1
Original line number Diff line number Diff line
@@ -362,7 +362,6 @@ extern void dl_server_start(struct sched_dl_entity *dl_se); 
extern void dl_server_stop(struct sched_dl_entity *dl_se);

extern void dl_server_init(struct sched_dl_entity *dl_se, struct rq *rq,

		    dl_server_has_tasks_f has_tasks,

		    dl_server_pick_f pick_next,

		    dl_server_pick_f pick_task);



extern void dl_server_update_idle_time(struct rq *rq,