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sched/smp: Use the SMP version of the RT scheduling class

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Simplify the scheduler by making CONFIG_SMP=y primitives and data
structures unconditional in the RT policies scheduler.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Shrikanth Hegde <sshegde@linux.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20250528080924.2273858-29-mingo@kernel.org
This commit is contained in:
Ingo Molnar
2025-06-13 08:47:20 +02:00
parent 74063c1755
commit 15125a229a
2 changed files with 0 additions and 74 deletions
Download Patch File Download Diff File Expand all files Collapse all files
kernel/sched/rt.c
-72
View File
@@ -78,12 +78,10 @@ void init_rt_rq(struct rt_rq *rt_rq)
/* delimiter for bitsearch: */
__set_bit(MAX_RT_PRIO, array->bitmap);
#if defined CONFIG_SMP
rt_rq->highest_prio.curr = MAX_RT_PRIO-1;
rt_rq->highest_prio.next = MAX_RT_PRIO-1;
rt_rq->overloaded = 0;
plist_head_init(&rt_rq->pushable_tasks);
#endif /* CONFIG_SMP */
/* We start is dequeued state, because no RT tasks are queued */
rt_rq->rt_queued = 0;
@@ -332,8 +330,6 @@ int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)
}
#endif /* !CONFIG_RT_GROUP_SCHED */
#ifdef CONFIG_SMP
static inline bool need_pull_rt_task(struct rq *rq, struct task_struct *prev)
{
/* Try to pull RT tasks here if we lower this rq's prio */
@@ -433,21 +429,6 @@ static void dequeue_pushable_task(struct rq *rq, struct task_struct *p)
}
}
#else /* !CONFIG_SMP: */
static inline void enqueue_pushable_task(struct rq *rq, struct task_struct *p)
{
}
static inline void dequeue_pushable_task(struct rq *rq, struct task_struct *p)
{
}
static inline void rt_queue_push_tasks(struct rq *rq)
{
}
#endif /* !CONFIG_SMP */
static void enqueue_top_rt_rq(struct rt_rq *rt_rq);
static void dequeue_top_rt_rq(struct rt_rq *rt_rq, unsigned int count);
@@ -597,17 +578,10 @@ static int rt_se_boosted(struct sched_rt_entity *rt_se)
return p->prio != p->normal_prio;
}
#ifdef CONFIG_SMP
static inline const struct cpumask *sched_rt_period_mask(void)
{
return this_rq()->rd->span;
}
#else
static inline const struct cpumask *sched_rt_period_mask(void)
{
return cpu_online_mask;
}
#endif
static inline
struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu)
@@ -628,7 +602,6 @@ bool sched_rt_bandwidth_account(struct rt_rq *rt_rq)
rt_rq->rt_time < rt_b->rt_runtime);
}
#ifdef CONFIG_SMP
/*
* We ran out of runtime, see if we can borrow some from our neighbours.
*/
@@ -801,9 +774,6 @@ static void balance_runtime(struct rt_rq *rt_rq)
raw_spin_lock(&rt_rq->rt_runtime_lock);
}
}
#else /* !CONFIG_SMP: */
static inline void balance_runtime(struct rt_rq *rt_rq) {}
#endif /* !CONFIG_SMP */
static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
{
@@ -980,10 +950,8 @@ struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu)
return &cpu_rq(cpu)->rt;
}
#ifdef CONFIG_SMP
static void __enable_runtime(struct rq *rq) { }
static void __disable_runtime(struct rq *rq) { }
#endif
#endif /* !CONFIG_RT_GROUP_SCHED */
@@ -1078,8 +1046,6 @@ enqueue_top_rt_rq(struct rt_rq *rt_rq)
cpufreq_update_util(rq, 0);
}
#if defined CONFIG_SMP
static void
inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio)
{
@@ -1110,16 +1076,6 @@ dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio)
cpupri_set(&rq->rd->cpupri, rq->cpu, rt_rq->highest_prio.curr);
}
#else /* !CONFIG_SMP: */
static inline
void inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {}
static inline
void dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {}
#endif /* !CONFIG_SMP */
#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
static void
inc_rt_prio(struct rt_rq *rt_rq, int prio)
{
@@ -1158,13 +1114,6 @@ dec_rt_prio(struct rt_rq *rt_rq, int prio)
dec_rt_prio_smp(rt_rq, prio, prev_prio);
}
#else /* !(CONFIG_SMP || CONFIG_RT_GROUP_SCHED): */
static inline void inc_rt_prio(struct rt_rq *rt_rq, int prio) {}
static inline void dec_rt_prio(struct rt_rq *rt_rq, int prio) {}
#endif /* !(CONFIG_SMP || CONFIG_RT_GROUP_SCHED) */
#ifdef CONFIG_RT_GROUP_SCHED
static void
@@ -1541,7 +1490,6 @@ static void yield_task_rt(struct rq *rq)
requeue_task_rt(rq, rq->curr, 0);
}
#ifdef CONFIG_SMP
static int find_lowest_rq(struct task_struct *task);
static int
@@ -1656,7 +1604,6 @@ static int balance_rt(struct rq *rq, struct task_struct *p, struct rq_flags *rf)
return sched_stop_runnable(rq) || sched_dl_runnable(rq) || sched_rt_runnable(rq);
}
#endif /* CONFIG_SMP */
/*
* Preempt the current task with a newly woken task if needed:
@@ -1670,7 +1617,6 @@ static void wakeup_preempt_rt(struct rq *rq, struct task_struct *p, int flags)
return;
}
#ifdef CONFIG_SMP
/*
* If:
*
@@ -1685,7 +1631,6 @@ static void wakeup_preempt_rt(struct rq *rq, struct task_struct *p, int flags)
*/
if (p->prio == donor->prio && !test_tsk_need_resched(rq->curr))
check_preempt_equal_prio(rq, p);
#endif /* CONFIG_SMP */
}
static inline void set_next_task_rt(struct rq *rq, struct task_struct *p, bool first)
@@ -1779,8 +1724,6 @@ static void put_prev_task_rt(struct rq *rq, struct task_struct *p, struct task_s
enqueue_pushable_task(rq, p);
}
#ifdef CONFIG_SMP
/* Only try algorithms three times */
#define RT_MAX_TRIES 3
@@ -2454,11 +2397,6 @@ void __init init_sched_rt_class(void)
GFP_KERNEL, cpu_to_node(i));
}
}
#else /* !CONFIG_SMP: */
void __init init_sched_rt_class(void)
{
}
#endif /* !CONFIG_SMP */
/*
* When switching a task to RT, we may overload the runqueue
@@ -2482,10 +2420,8 @@ static void switched_to_rt(struct rq *rq, struct task_struct *p)
* then see if we can move to another run queue.
*/
if (task_on_rq_queued(p)) {
#ifdef CONFIG_SMP
if (p->nr_cpus_allowed > 1 && rq->rt.overloaded)
rt_queue_push_tasks(rq);
#endif /* CONFIG_SMP */
if (p->prio < rq->donor->prio && cpu_online(cpu_of(rq)))
resched_curr(rq);
}
@@ -2502,7 +2438,6 @@ prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio)
return;
if (task_current_donor(rq, p)) {
#ifdef CONFIG_SMP
/*
* If our priority decreases while running, we
* may need to pull tasks to this runqueue.
@@ -2516,11 +2451,6 @@ prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio)
*/
if (p->prio > rq->rt.highest_prio.curr)
resched_curr(rq);
#else /* !CONFIG_SMP: */
/* For UP simply resched on drop of prio */
if (oldprio < p->prio)
resched_curr(rq);
#endif /* !CONFIG_SMP */
} else {
/*
* This task is not running, but if it is
@@ -2641,7 +2571,6 @@ DEFINE_SCHED_CLASS(rt) = {
.put_prev_task = put_prev_task_rt,
.set_next_task = set_next_task_rt,
#ifdef CONFIG_SMP
.balance = balance_rt,
.select_task_rq = select_task_rq_rt,
.set_cpus_allowed = set_cpus_allowed_common,
@@ -2650,7 +2579,6 @@ DEFINE_SCHED_CLASS(rt) = {
.task_woken = task_woken_rt,
.switched_from = switched_from_rt,
.find_lock_rq = find_lock_lowest_rq,
#endif /* !CONFIG_SMP */
.task_tick = task_tick_rt,
kernel/sched/sched.h
-2
View File
@@ -792,11 +792,9 @@ struct rt_rq {
int curr; /* highest queued rt task prio */
int next; /* next highest */
} highest_prio;
#ifdef CONFIG_SMP
bool overloaded;
struct plist_head pushable_tasks;
#endif /* CONFIG_SMP */
int rt_queued;
#ifdef CONFIG_RT_GROUP_SCHED