mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-11-24 14:20:55 +07:00
4ce72a2c06
a patch from Henrik Austad did this: >> Do not declare select_task_rq as part of sched_class when CONFIG_SMP is >> not set. Peter observed: > While a proper cleanup, could you do it by re-arranging the methods so > as to not create an additional ifdef? Do not declare select_task_rq and some other methods as part of sched_class when CONFIG_SMP is not set. Also gather those methods to avoid CONFIG_SMP mess. Idea-by: Henrik Austad <henrik.austad@gmail.com> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Henrik Austad <henrik@austad.us> Signed-off-by: Ingo Molnar <mingo@elte.hu>
129 lines
2.9 KiB
C
129 lines
2.9 KiB
C
/*
|
|
* idle-task scheduling class.
|
|
*
|
|
* (NOTE: these are not related to SCHED_IDLE tasks which are
|
|
* handled in sched_fair.c)
|
|
*/
|
|
|
|
#ifdef CONFIG_SMP
|
|
static int select_task_rq_idle(struct task_struct *p, int sync)
|
|
{
|
|
return task_cpu(p); /* IDLE tasks as never migrated */
|
|
}
|
|
#endif /* CONFIG_SMP */
|
|
/*
|
|
* Idle tasks are unconditionally rescheduled:
|
|
*/
|
|
static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p, int sync)
|
|
{
|
|
resched_task(rq->idle);
|
|
}
|
|
|
|
static struct task_struct *pick_next_task_idle(struct rq *rq)
|
|
{
|
|
schedstat_inc(rq, sched_goidle);
|
|
|
|
return rq->idle;
|
|
}
|
|
|
|
/*
|
|
* It is not legal to sleep in the idle task - print a warning
|
|
* message if some code attempts to do it:
|
|
*/
|
|
static void
|
|
dequeue_task_idle(struct rq *rq, struct task_struct *p, int sleep)
|
|
{
|
|
spin_unlock_irq(&rq->lock);
|
|
printk(KERN_ERR "bad: scheduling from the idle thread!\n");
|
|
dump_stack();
|
|
spin_lock_irq(&rq->lock);
|
|
}
|
|
|
|
static void put_prev_task_idle(struct rq *rq, struct task_struct *prev)
|
|
{
|
|
}
|
|
|
|
#ifdef CONFIG_SMP
|
|
static unsigned long
|
|
load_balance_idle(struct rq *this_rq, int this_cpu, struct rq *busiest,
|
|
unsigned long max_load_move,
|
|
struct sched_domain *sd, enum cpu_idle_type idle,
|
|
int *all_pinned, int *this_best_prio)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
move_one_task_idle(struct rq *this_rq, int this_cpu, struct rq *busiest,
|
|
struct sched_domain *sd, enum cpu_idle_type idle)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static void task_tick_idle(struct rq *rq, struct task_struct *curr, int queued)
|
|
{
|
|
}
|
|
|
|
static void set_curr_task_idle(struct rq *rq)
|
|
{
|
|
}
|
|
|
|
static void switched_to_idle(struct rq *rq, struct task_struct *p,
|
|
int running)
|
|
{
|
|
/* Can this actually happen?? */
|
|
if (running)
|
|
resched_task(rq->curr);
|
|
else
|
|
check_preempt_curr(rq, p, 0);
|
|
}
|
|
|
|
static void prio_changed_idle(struct rq *rq, struct task_struct *p,
|
|
int oldprio, int running)
|
|
{
|
|
/* This can happen for hot plug CPUS */
|
|
|
|
/*
|
|
* Reschedule if we are currently running on this runqueue and
|
|
* our priority decreased, or if we are not currently running on
|
|
* this runqueue and our priority is higher than the current's
|
|
*/
|
|
if (running) {
|
|
if (p->prio > oldprio)
|
|
resched_task(rq->curr);
|
|
} else
|
|
check_preempt_curr(rq, p, 0);
|
|
}
|
|
|
|
/*
|
|
* Simple, special scheduling class for the per-CPU idle tasks:
|
|
*/
|
|
static const struct sched_class idle_sched_class = {
|
|
/* .next is NULL */
|
|
/* no enqueue/yield_task for idle tasks */
|
|
|
|
/* dequeue is not valid, we print a debug message there: */
|
|
.dequeue_task = dequeue_task_idle,
|
|
|
|
.check_preempt_curr = check_preempt_curr_idle,
|
|
|
|
.pick_next_task = pick_next_task_idle,
|
|
.put_prev_task = put_prev_task_idle,
|
|
|
|
#ifdef CONFIG_SMP
|
|
.select_task_rq = select_task_rq_idle,
|
|
|
|
.load_balance = load_balance_idle,
|
|
.move_one_task = move_one_task_idle,
|
|
#endif
|
|
|
|
.set_curr_task = set_curr_task_idle,
|
|
.task_tick = task_tick_idle,
|
|
|
|
.prio_changed = prio_changed_idle,
|
|
.switched_to = switched_to_idle,
|
|
|
|
/* no .task_new for idle tasks */
|
|
};
|