Commit 6455ad53 authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

sched: Move sched_class::prio_changed() into the change pattern 



Move sched_class::prio_changed() into the change pattern.

And while there, extend it with sched_class::get_prio() in order to
fix the deadline sitation.

Suggested-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarJuri Lelli <juri.lelli@redhat.com>
Acked-by: default avatarTejun Heo <tj@kernel.org>
Acked-by: default avatarVincent Guittot <vincent.guittot@linaro.org>
parent 1ae5f5df

kernel/sched/core.c

+13 −11
Original line number Diff line number Diff line
@@ -2169,12 +2169,6 @@ inline int task_curr(const struct task_struct *p) 
	return cpu_curr(task_cpu(p)) == p;

}



void check_prio_changed(struct rq *rq, struct task_struct *p, int oldprio)

{

	if (oldprio != p->prio || dl_task(p))

		p->sched_class->prio_changed(rq, p, oldprio);

}



void wakeup_preempt(struct rq *rq, struct task_struct *p, int flags)

{

	struct task_struct *donor = rq->donor;
@@ -7400,9 +7394,6 @@ void rt_mutex_setprio(struct task_struct *p, struct task_struct *pi_task) 
		p->sched_class = next_class;

		p->prio = prio;

	}



	if (!(queue_flag & DEQUEUE_CLASS))

		check_prio_changed(rq, p, oldprio);

out_unlock:

	/* Avoid rq from going away on us: */

	preempt_disable();
@@ -10855,6 +10846,13 @@ struct sched_change_ctx *sched_change_begin(struct task_struct *p, unsigned int 
		.running = task_current_donor(rq, p),

	};



	if (!(flags & DEQUEUE_CLASS)) {

		if (p->sched_class->get_prio)

			ctx->prio = p->sched_class->get_prio(rq, p);

		else

			ctx->prio = p->prio;

	}



	if (ctx->queued)

		dequeue_task(rq, p, flags);

	if (ctx->running)
@@ -10881,6 +10879,10 @@ void sched_change_end(struct sched_change_ctx *ctx) 
	if (ctx->running)

		set_next_task(rq, p);



	if ((ctx->flags & ENQUEUE_CLASS) && p->sched_class->switched_to)

	if (ctx->flags & ENQUEUE_CLASS) {

		if (p->sched_class->switched_to)

			p->sched_class->switched_to(rq, p);

	} else {

		p->sched_class->prio_changed(rq, p, ctx->prio);

	}

}

kernel/sched/deadline.c

+11 −9
Original line number Diff line number Diff line
@@ -3042,23 +3042,24 @@ static void switched_to_dl(struct rq *rq, struct task_struct *p) 
	}

}



static u64 get_prio_dl(struct rq *rq, struct task_struct *p)

{

	return p->dl.deadline;

}



/*

 * If the scheduling parameters of a -deadline task changed,

 * a push or pull operation might be needed.

 */

static void prio_changed_dl(struct rq *rq, struct task_struct *p,

			    int oldprio)

static void prio_changed_dl(struct rq *rq, struct task_struct *p, u64 old_deadline)

{

	if (!task_on_rq_queued(p))

		return;



	/*

	 * This might be too much, but unfortunately

	 * we don't have the old deadline value, and

	 * we can't argue if the task is increasing

	 * or lowering its prio, so...

	 */

	if (!rq->dl.overloaded)

	if (p->dl.deadline == old_deadline)

		return;



	if (dl_time_before(old_deadline, p->dl.deadline))

		deadline_queue_pull_task(rq);



	if (task_current_donor(rq, p)) {
@@ -3113,6 +3114,7 @@ DEFINE_SCHED_CLASS(dl) = { 
	.task_tick		= task_tick_dl,

	.task_fork              = task_fork_dl,



	.get_prio		= get_prio_dl,

	.prio_changed           = prio_changed_dl,

	.switched_from		= switched_from_dl,

	.switched_to		= switched_to_dl,

kernel/sched/ext.c

+1 −7
Original line number Diff line number Diff line
@@ -2961,7 +2961,7 @@ static void reweight_task_scx(struct rq *rq, struct task_struct *p, 
				 p, p->scx.weight);

}



static void prio_changed_scx(struct rq *rq, struct task_struct *p, int oldprio)

static void prio_changed_scx(struct rq *rq, struct task_struct *p, u64 oldprio)

{

}
@@ -3926,9 +3926,6 @@ static void scx_disable_workfn(struct kthread_work *work) 
			p->sched_class = new_class;

		}



		if (!(queue_flags & DEQUEUE_CLASS))

			check_prio_changed(task_rq(p), p, p->prio);



		scx_exit_task(p);

	}

	scx_task_iter_stop(&sti);
@@ -4675,9 +4672,6 @@ static int scx_enable(struct sched_ext_ops *ops, struct bpf_link *link) 
			p->sched_class = new_class;

		}



		if (!(queue_flags & DEQUEUE_CLASS))

			check_prio_changed(task_rq(p), p, p->prio);



		put_task_struct(p);

	}

	scx_task_iter_stop(&sti);

kernel/sched/fair.c

+6 −2
Original line number Diff line number Diff line
@@ -13150,11 +13150,14 @@ static void task_fork_fair(struct task_struct *p) 
 * the current task.

 */

static void

prio_changed_fair(struct rq *rq, struct task_struct *p, int oldprio)

prio_changed_fair(struct rq *rq, struct task_struct *p, u64 oldprio)

{

	if (!task_on_rq_queued(p))

		return;



	if (p->prio == oldprio)

		return;



	if (rq->cfs.nr_queued == 1)

		return;
@@ -13166,9 +13169,10 @@ prio_changed_fair(struct rq *rq, struct task_struct *p, int oldprio) 
	if (task_current_donor(rq, p)) {

		if (p->prio > oldprio)

			resched_curr(rq);

	} else

	} else {

		wakeup_preempt(rq, p, 0);

	}

}



#ifdef CONFIG_FAIR_GROUP_SCHED

/*

kernel/sched/idle.c

+4 −1
Original line number Diff line number Diff line
@@ -504,8 +504,11 @@ static void switching_to_idle(struct rq *rq, struct task_struct *p) 
}



static void

prio_changed_idle(struct rq *rq, struct task_struct *p, int oldprio)

prio_changed_idle(struct rq *rq, struct task_struct *p, u64 oldprio)

{

	if (p->prio == oldprio)

		return;



	BUG();

}