diff options
Diffstat (limited to 'kernel/sched/rt.c')
| -rw-r--r-- | kernel/sched/rt.c | 856 |
1 files changed, 519 insertions, 337 deletions
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index f395ddb75f38..4b8e33c615b1 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -3,18 +3,98 @@ * Real-Time Scheduling Class (mapped to the SCHED_FIFO and SCHED_RR * policies) */ -#include "sched.h" - -#include "pelt.h" int sched_rr_timeslice = RR_TIMESLICE; -int sysctl_sched_rr_timeslice = (MSEC_PER_SEC / HZ) * RR_TIMESLICE; /* More than 4 hours if BW_SHIFT equals 20. */ static const u64 max_rt_runtime = MAX_BW; -static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun); +/* + * period over which we measure -rt task CPU usage in us. + * default: 1s + */ +int sysctl_sched_rt_period = 1000000; + +/* + * part of the period that we allow rt tasks to run in us. + * default: 0.95s + */ +int sysctl_sched_rt_runtime = 950000; + +#ifdef CONFIG_SYSCTL +static int sysctl_sched_rr_timeslice = (MSEC_PER_SEC * RR_TIMESLICE) / HZ; +static int sched_rt_handler(const struct ctl_table *table, int write, void *buffer, + size_t *lenp, loff_t *ppos); +static int sched_rr_handler(const struct ctl_table *table, int write, void *buffer, + size_t *lenp, loff_t *ppos); +static const struct ctl_table sched_rt_sysctls[] = { + { + .procname = "sched_rt_period_us", + .data = &sysctl_sched_rt_period, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = sched_rt_handler, + .extra1 = SYSCTL_ONE, + .extra2 = SYSCTL_INT_MAX, + }, + { + .procname = "sched_rt_runtime_us", + .data = &sysctl_sched_rt_runtime, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = sched_rt_handler, + .extra1 = SYSCTL_NEG_ONE, + .extra2 = (void *)&sysctl_sched_rt_period, + }, + { + .procname = "sched_rr_timeslice_ms", + .data = &sysctl_sched_rr_timeslice, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = sched_rr_handler, + }, +}; + +static int __init sched_rt_sysctl_init(void) +{ + register_sysctl_init("kernel", sched_rt_sysctls); + return 0; +} +late_initcall(sched_rt_sysctl_init); +#endif + +void init_rt_rq(struct rt_rq *rt_rq) +{ + struct rt_prio_array *array; + int i; + + array = &rt_rq->active; + for (i = 0; i < MAX_RT_PRIO; i++) { + INIT_LIST_HEAD(array->queue + i); + __clear_bit(i, array->bitmap); + } + /* delimiter for bitsearch: */ + __set_bit(MAX_RT_PRIO, array->bitmap); -struct rt_bandwidth def_rt_bandwidth; +#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; + +#ifdef CONFIG_RT_GROUP_SCHED + rt_rq->rt_time = 0; + rt_rq->rt_throttled = 0; + rt_rq->rt_runtime = 0; + raw_spin_lock_init(&rt_rq->rt_runtime_lock); +#endif +} + +#ifdef CONFIG_RT_GROUP_SCHED + +static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun); static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer) { @@ -52,11 +132,8 @@ void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime) rt_b->rt_period_timer.function = sched_rt_period_timer; } -static void start_rt_bandwidth(struct rt_bandwidth *rt_b) +static inline void do_start_rt_bandwidth(struct rt_bandwidth *rt_b) { - if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF) - return; - raw_spin_lock(&rt_b->rt_runtime_lock); if (!rt_b->rt_period_active) { rt_b->rt_period_active = 1; @@ -75,36 +152,14 @@ static void start_rt_bandwidth(struct rt_bandwidth *rt_b) raw_spin_unlock(&rt_b->rt_runtime_lock); } -void init_rt_rq(struct rt_rq *rt_rq) +static void start_rt_bandwidth(struct rt_bandwidth *rt_b) { - struct rt_prio_array *array; - int i; - - array = &rt_rq->active; - for (i = 0; i < MAX_RT_PRIO; i++) { - INIT_LIST_HEAD(array->queue + i); - __clear_bit(i, array->bitmap); - } - /* delimiter for bitsearch: */ - __set_bit(MAX_RT_PRIO, array->bitmap); - -#if defined CONFIG_SMP - rt_rq->highest_prio.curr = MAX_RT_PRIO; - rt_rq->highest_prio.next = MAX_RT_PRIO; - rt_rq->rt_nr_migratory = 0; - 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; + if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF) + return; - rt_rq->rt_time = 0; - rt_rq->rt_throttled = 0; - rt_rq->rt_runtime = 0; - raw_spin_lock_init(&rt_rq->rt_runtime_lock); + do_start_rt_bandwidth(rt_b); } -#ifdef CONFIG_RT_GROUP_SCHED static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b) { hrtimer_cancel(&rt_b->rt_period_timer); @@ -137,12 +192,15 @@ static inline struct rq *rq_of_rt_se(struct sched_rt_entity *rt_se) return rt_rq->rq; } -void free_rt_sched_group(struct task_group *tg) +void unregister_rt_sched_group(struct task_group *tg) { - int i; - if (tg->rt_se) destroy_rt_bandwidth(&tg->rt_bandwidth); +} + +void free_rt_sched_group(struct task_group *tg) +{ + int i; for_each_possible_cpu(i) { if (tg->rt_rq) @@ -161,7 +219,7 @@ void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, { struct rq *rq = cpu_rq(cpu); - rt_rq->highest_prio.curr = MAX_RT_PRIO; + rt_rq->highest_prio.curr = MAX_RT_PRIO-1; rt_rq->rt_nr_boosted = 0; rt_rq->rq = rq; rt_rq->tg = tg; @@ -195,8 +253,7 @@ int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) if (!tg->rt_se) goto err; - init_rt_bandwidth(&tg->rt_bandwidth, - ktime_to_ns(def_rt_bandwidth.rt_period), 0); + init_rt_bandwidth(&tg->rt_bandwidth, ktime_to_ns(global_rt_period()), 0); for_each_possible_cpu(i) { rt_rq = kzalloc_node(sizeof(struct rt_rq), @@ -250,6 +307,8 @@ static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se) return &rq->rt; } +void unregister_rt_sched_group(struct task_group *tg) { } + void free_rt_sched_group(struct task_group *tg) { } int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) @@ -260,12 +319,10 @@ int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) #ifdef CONFIG_SMP -static void pull_rt_task(struct rq *this_rq); - 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 */ - return rq->rt.highest_prio.curr > prev->prio; + return rq->online && rq->rt.highest_prio.curr > prev->prio; } static inline int rt_overloaded(struct rq *rq) @@ -302,60 +359,13 @@ static inline void rt_clear_overload(struct rq *rq) cpumask_clear_cpu(rq->cpu, rq->rd->rto_mask); } -static void update_rt_migration(struct rt_rq *rt_rq) -{ - if (rt_rq->rt_nr_migratory && rt_rq->rt_nr_total > 1) { - if (!rt_rq->overloaded) { - rt_set_overload(rq_of_rt_rq(rt_rq)); - rt_rq->overloaded = 1; - } - } else if (rt_rq->overloaded) { - rt_clear_overload(rq_of_rt_rq(rt_rq)); - rt_rq->overloaded = 0; - } -} - -static void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) -{ - struct task_struct *p; - - if (!rt_entity_is_task(rt_se)) - return; - - p = rt_task_of(rt_se); - rt_rq = &rq_of_rt_rq(rt_rq)->rt; - - rt_rq->rt_nr_total++; - if (p->nr_cpus_allowed > 1) - rt_rq->rt_nr_migratory++; - - update_rt_migration(rt_rq); -} - -static void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) -{ - struct task_struct *p; - - if (!rt_entity_is_task(rt_se)) - return; - - p = rt_task_of(rt_se); - rt_rq = &rq_of_rt_rq(rt_rq)->rt; - - rt_rq->rt_nr_total--; - if (p->nr_cpus_allowed > 1) - rt_rq->rt_nr_migratory--; - - update_rt_migration(rt_rq); -} - static inline int has_pushable_tasks(struct rq *rq) { return !plist_head_empty(&rq->rt.pushable_tasks); } -static DEFINE_PER_CPU(struct callback_head, rt_push_head); -static DEFINE_PER_CPU(struct callback_head, rt_pull_head); +static DEFINE_PER_CPU(struct balance_callback, rt_push_head); +static DEFINE_PER_CPU(struct balance_callback, rt_pull_head); static void push_rt_tasks(struct rq *); static void pull_rt_task(struct rq *); @@ -382,6 +392,11 @@ static void enqueue_pushable_task(struct rq *rq, struct task_struct *p) /* Update the highest prio pushable task */ if (p->prio < rq->rt.highest_prio.next) rq->rt.highest_prio.next = p->prio; + + if (!rq->rt.overloaded) { + rt_set_overload(rq); + rq->rt.overloaded = 1; + } } static void dequeue_pushable_task(struct rq *rq, struct task_struct *p) @@ -393,8 +408,14 @@ static void dequeue_pushable_task(struct rq *rq, struct task_struct *p) p = plist_first_entry(&rq->rt.pushable_tasks, struct task_struct, pushable_tasks); rq->rt.highest_prio.next = p->prio; - } else - rq->rt.highest_prio.next = MAX_RT_PRIO; + } else { + rq->rt.highest_prio.next = MAX_RT_PRIO-1; + + if (rq->rt.overloaded) { + rt_clear_overload(rq); + rq->rt.overloaded = 0; + } + } } #else @@ -407,32 +428,13 @@ static inline void dequeue_pushable_task(struct rq *rq, struct task_struct *p) { } -static inline -void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) -{ -} - -static inline -void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) -{ -} - -static inline bool need_pull_rt_task(struct rq *rq, struct task_struct *prev) -{ - return false; -} - -static inline void pull_rt_task(struct rq *this_rq) -{ -} - 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); +static void dequeue_top_rt_rq(struct rt_rq *rt_rq, unsigned int count); static inline int on_rt_rq(struct sched_rt_entity *rt_se) { @@ -461,13 +463,13 @@ static inline bool rt_task_fits_capacity(struct task_struct *p, int cpu) unsigned int cpu_cap; /* Only heterogeneous systems can benefit from this check */ - if (!static_branch_unlikely(&sched_asym_cpucapacity)) + if (!sched_asym_cpucap_active()) return true; min_cap = uclamp_eff_value(p, UCLAMP_MIN); max_cap = uclamp_eff_value(p, UCLAMP_MAX); - cpu_cap = capacity_orig_of(cpu); + cpu_cap = arch_scale_cpu_capacity(cpu); return cpu_cap >= min(min_cap, max_cap); } @@ -526,7 +528,7 @@ static void dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags) static void sched_rt_rq_enqueue(struct rt_rq *rt_rq) { - struct task_struct *curr = rq_of_rt_rq(rt_rq)->curr; + struct task_struct *donor = rq_of_rt_rq(rt_rq)->donor; struct rq *rq = rq_of_rt_rq(rt_rq); struct sched_rt_entity *rt_se; @@ -540,7 +542,7 @@ static void sched_rt_rq_enqueue(struct rt_rq *rt_rq) else if (!on_rt_rq(rt_se)) enqueue_rt_entity(rt_se, 0); - if (rt_rq->highest_prio.curr < curr->prio) + if (rt_rq->highest_prio.curr < donor->prio) resched_curr(rq); } } @@ -553,7 +555,7 @@ static void sched_rt_rq_dequeue(struct rt_rq *rt_rq) rt_se = rt_rq->tg->rt_se[cpu]; if (!rt_se) { - dequeue_top_rt_rq(rt_rq); + dequeue_top_rt_rq(rt_rq, rt_rq->rt_nr_running); /* Kick cpufreq (see the comment in kernel/sched/sched.h). */ cpufreq_update_util(rq_of_rt_rq(rt_rq), 0); } @@ -601,70 +603,6 @@ static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq) return &rt_rq->tg->rt_bandwidth; } -#else /* !CONFIG_RT_GROUP_SCHED */ - -static inline u64 sched_rt_runtime(struct rt_rq *rt_rq) -{ - return rt_rq->rt_runtime; -} - -static inline u64 sched_rt_period(struct rt_rq *rt_rq) -{ - return ktime_to_ns(def_rt_bandwidth.rt_period); -} - -typedef struct rt_rq *rt_rq_iter_t; - -#define for_each_rt_rq(rt_rq, iter, rq) \ - for ((void) iter, rt_rq = &rq->rt; rt_rq; rt_rq = NULL) - -#define for_each_sched_rt_entity(rt_se) \ - for (; rt_se; rt_se = NULL) - -static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) -{ - return NULL; -} - -static inline void sched_rt_rq_enqueue(struct rt_rq *rt_rq) -{ - struct rq *rq = rq_of_rt_rq(rt_rq); - - if (!rt_rq->rt_nr_running) - return; - - enqueue_top_rt_rq(rt_rq); - resched_curr(rq); -} - -static inline void sched_rt_rq_dequeue(struct rt_rq *rt_rq) -{ - dequeue_top_rt_rq(rt_rq); -} - -static inline int rt_rq_throttled(struct rt_rq *rt_rq) -{ - return rt_rq->rt_throttled; -} - -static inline const struct cpumask *sched_rt_period_mask(void) -{ - return cpu_online_mask; -} - -static inline -struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu) -{ - return &cpu_rq(cpu)->rt; -} - -static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq) -{ - return &def_rt_bandwidth; -} - -#endif /* CONFIG_RT_GROUP_SCHED */ - bool sched_rt_bandwidth_account(struct rt_rq *rt_rq) { struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); @@ -699,7 +637,7 @@ static void do_balance_runtime(struct rt_rq *rt_rq) /* * Either all rqs have inf runtime and there's nothing to steal * or __disable_runtime() below sets a specific rq to inf to - * indicate its been disabled and disalow stealing. + * indicate its been disabled and disallow stealing. */ if (iter->rt_runtime == RUNTIME_INF) goto next; @@ -795,7 +733,7 @@ static void __disable_runtime(struct rq *rq) * We cannot be left wanting - that would mean some runtime * leaked out of the system. */ - BUG_ON(want); + WARN_ON_ONCE(want); balanced: /* * Disable all the borrow logic by pretending we have inf @@ -856,7 +794,7 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) const struct cpumask *span; span = sched_rt_period_mask(); -#ifdef CONFIG_RT_GROUP_SCHED + /* * FIXME: isolated CPUs should really leave the root task group, * whether they are isolcpus or were isolated via cpusets, lest @@ -868,11 +806,12 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) */ if (rt_b == &root_task_group.rt_bandwidth) span = cpu_online_mask; -#endif + for_each_cpu(i, span) { int enqueue = 0; struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i); struct rq *rq = rq_of_rt_rq(rt_rq); + struct rq_flags rf; int skip; /* @@ -887,7 +826,7 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) if (skip) continue; - raw_spin_lock(&rq->lock); + rq_lock(rq, &rf); update_rq_clock(rq); if (rt_rq->rt_time) { @@ -904,7 +843,7 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) /* * When we're idle and a woken (rt) task is - * throttled check_preempt_curr() will set + * throttled wakeup_preempt() will set * skip_update and the time between the wakeup * and this unthrottle will get accounted as * 'runtime'. @@ -925,7 +864,7 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) if (enqueue) sched_rt_rq_enqueue(rt_rq); - raw_spin_unlock(&rq->lock); + rq_unlock(rq, &rf); } if (!throttled && (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)) @@ -934,18 +873,6 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) return idle; } -static inline int rt_se_prio(struct sched_rt_entity *rt_se) -{ -#ifdef CONFIG_RT_GROUP_SCHED - struct rt_rq *rt_rq = group_rt_rq(rt_se); - - if (rt_rq) - return rt_rq->highest_prio.curr; -#endif - - return rt_task_of(rt_se)->prio; -} - static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq) { u64 runtime = sched_rt_runtime(rt_rq); @@ -989,52 +916,114 @@ static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq) return 0; } +#else /* !CONFIG_RT_GROUP_SCHED */ + +typedef struct rt_rq *rt_rq_iter_t; + +#define for_each_rt_rq(rt_rq, iter, rq) \ + for ((void) iter, rt_rq = &rq->rt; rt_rq; rt_rq = NULL) + +#define for_each_sched_rt_entity(rt_se) \ + for (; rt_se; rt_se = NULL) + +static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) +{ + return NULL; +} + +static inline void sched_rt_rq_enqueue(struct rt_rq *rt_rq) +{ + struct rq *rq = rq_of_rt_rq(rt_rq); + + if (!rt_rq->rt_nr_running) + return; + + enqueue_top_rt_rq(rt_rq); + resched_curr(rq); +} + +static inline void sched_rt_rq_dequeue(struct rt_rq *rt_rq) +{ + dequeue_top_rt_rq(rt_rq, rt_rq->rt_nr_running); +} + +static inline int rt_rq_throttled(struct rt_rq *rt_rq) +{ + return false; +} + +static inline const struct cpumask *sched_rt_period_mask(void) +{ + return cpu_online_mask; +} + +static inline +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 */ + +static inline int rt_se_prio(struct sched_rt_entity *rt_se) +{ +#ifdef CONFIG_RT_GROUP_SCHED + struct rt_rq *rt_rq = group_rt_rq(rt_se); + + if (rt_rq) + return rt_rq->highest_prio.curr; +#endif + + return rt_task_of(rt_se)->prio; +} + /* * Update the current task's runtime statistics. Skip current tasks that * are not in our scheduling class. */ static void update_curr_rt(struct rq *rq) { - struct task_struct *curr = rq->curr; - struct sched_rt_entity *rt_se = &curr->rt; - u64 delta_exec; - u64 now; + struct task_struct *donor = rq->donor; + s64 delta_exec; - if (curr->sched_class != &rt_sched_class) + if (donor->sched_class != &rt_sched_class) return; - now = rq_clock_task(rq); - delta_exec = now - curr->se.exec_start; - if (unlikely((s64)delta_exec <= 0)) + delta_exec = update_curr_common(rq); + if (unlikely(delta_exec <= 0)) return; - schedstat_set(curr->se.statistics.exec_max, - max(curr->se.statistics.exec_max, delta_exec)); - - curr->se.sum_exec_runtime += delta_exec; - account_group_exec_runtime(curr, delta_exec); - - curr->se.exec_start = now; - cgroup_account_cputime(curr, delta_exec); +#ifdef CONFIG_RT_GROUP_SCHED + struct sched_rt_entity *rt_se = &donor->rt; if (!rt_bandwidth_enabled()) return; for_each_sched_rt_entity(rt_se) { struct rt_rq *rt_rq = rt_rq_of_se(rt_se); + int exceeded; if (sched_rt_runtime(rt_rq) != RUNTIME_INF) { raw_spin_lock(&rt_rq->rt_runtime_lock); rt_rq->rt_time += delta_exec; - if (sched_rt_runtime_exceeded(rt_rq)) + exceeded = sched_rt_runtime_exceeded(rt_rq); + if (exceeded) resched_curr(rq); raw_spin_unlock(&rt_rq->rt_runtime_lock); + if (exceeded) + do_start_rt_bandwidth(sched_rt_bandwidth(rt_rq)); } } +#endif } static void -dequeue_top_rt_rq(struct rt_rq *rt_rq) +dequeue_top_rt_rq(struct rt_rq *rt_rq, unsigned int count) { struct rq *rq = rq_of_rt_rq(rt_rq); @@ -1045,7 +1034,7 @@ dequeue_top_rt_rq(struct rt_rq *rt_rq) BUG_ON(!rq->nr_running); - sub_nr_running(rq, rt_rq->rt_nr_running); + sub_nr_running(rq, count); rt_rq->rt_queued = 0; } @@ -1138,7 +1127,7 @@ dec_rt_prio(struct rt_rq *rt_rq, int prio) /* * This may have been our highest task, and therefore - * we may have some recomputation to do + * we may have some re-computation to do */ if (prio == prev_prio) { struct rt_prio_array *array = &rt_rq->active; @@ -1147,8 +1136,9 @@ dec_rt_prio(struct rt_rq *rt_rq, int prio) sched_find_first_bit(array->bitmap); } - } else - rt_rq->highest_prio.curr = MAX_RT_PRIO; + } else { + rt_rq->highest_prio.curr = MAX_RT_PRIO-1; + } dec_rt_prio_smp(rt_rq, prio, prev_prio); } @@ -1186,7 +1176,6 @@ dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) static void inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) { - start_rt_bandwidth(&def_rt_bandwidth); } static inline @@ -1229,7 +1218,6 @@ void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) rt_rq->rr_nr_running += rt_se_rr_nr_running(rt_se); inc_rt_prio(rt_rq, prio); - inc_rt_migration(rt_se, rt_rq); inc_rt_group(rt_se, rt_rq); } @@ -1242,7 +1230,6 @@ void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) rt_rq->rr_nr_running -= rt_se_rr_nr_running(rt_se); dec_rt_prio(rt_rq, rt_se_prio(rt_se)); - dec_rt_migration(rt_se, rt_rq); dec_rt_group(rt_se, rt_rq); } @@ -1269,6 +1256,112 @@ static void __delist_rt_entity(struct sched_rt_entity *rt_se, struct rt_prio_arr rt_se->on_list = 0; } +static inline struct sched_statistics * +__schedstats_from_rt_se(struct sched_rt_entity *rt_se) +{ +#ifdef CONFIG_RT_GROUP_SCHED + /* schedstats is not supported for rt group. */ + if (!rt_entity_is_task(rt_se)) + return NULL; +#endif + + return &rt_task_of(rt_se)->stats; +} + +static inline void +update_stats_wait_start_rt(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se) +{ + struct sched_statistics *stats; + struct task_struct *p = NULL; + + if (!schedstat_enabled()) + return; + + if (rt_entity_is_task(rt_se)) + p = rt_task_of(rt_se); + + stats = __schedstats_from_rt_se(rt_se); + if (!stats) + return; + + __update_stats_wait_start(rq_of_rt_rq(rt_rq), p, stats); +} + +static inline void +update_stats_enqueue_sleeper_rt(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se) +{ + struct sched_statistics *stats; + struct task_struct *p = NULL; + + if (!schedstat_enabled()) + return; + + if (rt_entity_is_task(rt_se)) + p = rt_task_of(rt_se); + + stats = __schedstats_from_rt_se(rt_se); + if (!stats) + return; + + __update_stats_enqueue_sleeper(rq_of_rt_rq(rt_rq), p, stats); +} + +static inline void +update_stats_enqueue_rt(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, + int flags) +{ + if (!schedstat_enabled()) + return; + + if (flags & ENQUEUE_WAKEUP) + update_stats_enqueue_sleeper_rt(rt_rq, rt_se); +} + +static inline void +update_stats_wait_end_rt(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se) +{ + struct sched_statistics *stats; + struct task_struct *p = NULL; + + if (!schedstat_enabled()) + return; + + if (rt_entity_is_task(rt_se)) + p = rt_task_of(rt_se); + + stats = __schedstats_from_rt_se(rt_se); + if (!stats) + return; + + __update_stats_wait_end(rq_of_rt_rq(rt_rq), p, stats); +} + +static inline void +update_stats_dequeue_rt(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, + int flags) +{ + struct task_struct *p = NULL; + + if (!schedstat_enabled()) + return; + + if (rt_entity_is_task(rt_se)) + p = rt_task_of(rt_se); + + if ((flags & DEQUEUE_SLEEP) && p) { + unsigned int state; + + state = READ_ONCE(p->__state); + if (state & TASK_INTERRUPTIBLE) + __schedstat_set(p->stats.sleep_start, + rq_clock(rq_of_rt_rq(rt_rq))); + + if (state & TASK_UNINTERRUPTIBLE) + __schedstat_set(p->stats.block_start, + rq_clock(rq_of_rt_rq(rt_rq))); + } +} + static void __enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags) { struct rt_rq *rt_rq = rt_rq_of_se(rt_se); @@ -1324,24 +1417,29 @@ static void __dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flag static void dequeue_rt_stack(struct sched_rt_entity *rt_se, unsigned int flags) { struct sched_rt_entity *back = NULL; + unsigned int rt_nr_running; for_each_sched_rt_entity(rt_se) { rt_se->back = back; back = rt_se; } - dequeue_top_rt_rq(rt_rq_of_se(back)); + rt_nr_running = rt_rq_of_se(back)->rt_nr_running; for (rt_se = back; rt_se; rt_se = rt_se->back) { if (on_rt_rq(rt_se)) __dequeue_rt_entity(rt_se, flags); } + + dequeue_top_rt_rq(rt_rq_of_se(back), rt_nr_running); } static void enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags) { struct rq *rq = rq_of_rt_se(rt_se); + update_stats_enqueue_rt(rt_rq_of_se(rt_se), rt_se, flags); + dequeue_rt_stack(rt_se, flags); for_each_sched_rt_entity(rt_se) __enqueue_rt_entity(rt_se, flags); @@ -1352,6 +1450,8 @@ static void dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags) { struct rq *rq = rq_of_rt_se(rt_se); + update_stats_dequeue_rt(rt_rq_of_se(rt_se), rt_se, flags); + dequeue_rt_stack(rt_se, flags); for_each_sched_rt_entity(rt_se) { @@ -1374,13 +1474,16 @@ enqueue_task_rt(struct rq *rq, struct task_struct *p, int flags) if (flags & ENQUEUE_WAKEUP) rt_se->timeout = 0; + check_schedstat_required(); + update_stats_wait_start_rt(rt_rq_of_se(rt_se), rt_se); + enqueue_rt_entity(rt_se, flags); if (!task_current(rq, p) && p->nr_cpus_allowed > 1) enqueue_pushable_task(rq, p); } -static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags) +static bool dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags) { struct sched_rt_entity *rt_se = &p->rt; @@ -1388,6 +1491,8 @@ static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags) dequeue_rt_entity(rt_se, flags); dequeue_pushable_task(rq, p); + + return true; } /* @@ -1428,20 +1533,21 @@ static void yield_task_rt(struct rq *rq) static int find_lowest_rq(struct task_struct *task); static int -select_task_rq_rt(struct task_struct *p, int cpu, int sd_flag, int flags) +select_task_rq_rt(struct task_struct *p, int cpu, int flags) { - struct task_struct *curr; + struct task_struct *curr, *donor; struct rq *rq; bool test; /* For anything but wake ups, just return the task_cpu */ - if (sd_flag != SD_BALANCE_WAKE && sd_flag != SD_BALANCE_FORK) + if (!(flags & (WF_TTWU | WF_FORK))) goto out; rq = cpu_rq(cpu); rcu_read_lock(); curr = READ_ONCE(rq->curr); /* unlocked access */ + donor = READ_ONCE(rq->donor); /* * If the current task on @p's runqueue is an RT task, then @@ -1459,7 +1565,7 @@ select_task_rq_rt(struct task_struct *p, int cpu, int sd_flag, int flags) * * For equal prio tasks, we just let the scheduler sort it out. * - * Otherwise, just let it ride on the affined RQ and the + * Otherwise, just let it ride on the affine RQ and the * post-schedule router will push the preempted task away * * This test is optimistic, if we get it wrong the load-balancer @@ -1470,8 +1576,8 @@ select_task_rq_rt(struct task_struct *p, int cpu, int sd_flag, int flags) * systems like big.LITTLE. */ test = curr && - unlikely(rt_task(curr)) && - (curr->nr_cpus_allowed < 2 || curr->prio <= p->prio); + unlikely(rt_task(donor)) && + (curr->nr_cpus_allowed < 2 || donor->prio <= p->prio); if (test || !rt_task_fits_capacity(p, cpu)) { int target = find_lowest_rq(p); @@ -1501,12 +1607,8 @@ out: static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p) { - /* - * Current can't be migrated, useless to reschedule, - * let's hope p can move out. - */ if (rq->curr->nr_cpus_allowed == 1 || - !cpupri_find(&rq->rd->cpupri, rq->curr, NULL)) + !cpupri_find(&rq->rd->cpupri, rq->donor, NULL)) return; /* @@ -1547,9 +1649,11 @@ static int balance_rt(struct rq *rq, struct task_struct *p, struct rq_flags *rf) /* * Preempt the current task with a newly woken task if needed: */ -static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int flags) +static void wakeup_preempt_rt(struct rq *rq, struct task_struct *p, int flags) { - if (p->prio < rq->curr->prio) { + struct task_struct *donor = rq->donor; + + if (p->prio < donor->prio) { resched_curr(rq); return; } @@ -1567,14 +1671,19 @@ static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int flag * to move current somewhere else, making room for our non-migratable * task. */ - if (p->prio == rq->curr->prio && !test_tsk_need_resched(rq->curr)) + if (p->prio == donor->prio && !test_tsk_need_resched(rq->curr)) check_preempt_equal_prio(rq, p); #endif } static inline void set_next_task_rt(struct rq *rq, struct task_struct *p, bool first) { + struct sched_rt_entity *rt_se = &p->rt; + struct rt_rq *rt_rq = &rq->rt; + p->se.exec_start = rq_clock_task(rq); + if (on_rt_rq(&p->rt)) + update_stats_wait_end_rt(rt_rq, rt_se); /* The running task is never eligible for pushing */ dequeue_pushable_task(rq, p); @@ -1587,14 +1696,13 @@ static inline void set_next_task_rt(struct rq *rq, struct task_struct *p, bool f * utilization. We only care of the case where we start to schedule a * rt task */ - if (rq->curr->sched_class != &rt_sched_class) + if (rq->donor->sched_class != &rt_sched_class) update_rt_rq_load_avg(rq_clock_pelt(rq), rq, 0); rt_queue_push_tasks(rq); } -static struct sched_rt_entity *pick_next_rt_entity(struct rq *rq, - struct rt_rq *rt_rq) +static struct sched_rt_entity *pick_next_rt_entity(struct rt_rq *rt_rq) { struct rt_prio_array *array = &rt_rq->active; struct sched_rt_entity *next = NULL; @@ -1605,6 +1713,8 @@ static struct sched_rt_entity *pick_next_rt_entity(struct rq *rq, BUG_ON(idx >= MAX_RT_PRIO); queue = array->queue + idx; + if (SCHED_WARN_ON(list_empty(queue))) + return NULL; next = list_entry(queue->next, struct sched_rt_entity, run_list); return next; @@ -1616,15 +1726,16 @@ static struct task_struct *_pick_next_task_rt(struct rq *rq) struct rt_rq *rt_rq = &rq->rt; do { - rt_se = pick_next_rt_entity(rq, rt_rq); - BUG_ON(!rt_se); + rt_se = pick_next_rt_entity(rt_rq); + if (unlikely(!rt_se)) + return NULL; rt_rq = group_rt_rq(rt_se); } while (rt_rq); return rt_task_of(rt_se); } -static struct task_struct *pick_next_task_rt(struct rq *rq) +static struct task_struct *pick_task_rt(struct rq *rq) { struct task_struct *p; @@ -1632,12 +1743,18 @@ static struct task_struct *pick_next_task_rt(struct rq *rq) return NULL; p = _pick_next_task_rt(rq); - set_next_task_rt(rq, p, true); + return p; } -static void put_prev_task_rt(struct rq *rq, struct task_struct *p) +static void put_prev_task_rt(struct rq *rq, struct task_struct *p, struct task_struct *next) { + struct sched_rt_entity *rt_se = &p->rt; + struct rt_rq *rt_rq = &rq->rt; + + if (on_rt_rq(&p->rt)) + update_stats_wait_start_rt(rt_rq, rt_se); + update_curr_rt(rq); update_rt_rq_load_avg(rq_clock_pelt(rq), rq, 1); @@ -1655,15 +1772,6 @@ static void put_prev_task_rt(struct rq *rq, struct task_struct *p) /* Only try algorithms three times */ #define RT_MAX_TRIES 3 -static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu) -{ - if (!task_running(rq, p) && - cpumask_test_cpu(cpu, p->cpus_ptr)) - return 1; - - return 0; -} - /* * Return the highest pushable rq's task, which is suitable to be executed * on the CPU, NULL otherwise @@ -1677,7 +1785,7 @@ static struct task_struct *pick_highest_pushable_task(struct rq *rq, int cpu) return NULL; plist_for_each_entry(p, head, pushable_tasks) { - if (pick_rt_task(rq, p, cpu)) + if (task_is_pushable(rq, p, cpu)) return p; } @@ -1705,7 +1813,7 @@ static int find_lowest_rq(struct task_struct *task) * If we're on asym system ensure we consider the different capacities * of the CPUs when searching for the lowest_mask. */ - if (static_branch_unlikely(&sched_asym_cpucapacity)) { + if (sched_asym_cpucap_active()) { ret = cpupri_find_fitness(&task_rq(task)->rd->cpupri, task, lowest_mask, @@ -1752,8 +1860,8 @@ static int find_lowest_rq(struct task_struct *task) return this_cpu; } - best_cpu = cpumask_first_and(lowest_mask, - sched_domain_span(sd)); + best_cpu = cpumask_any_and_distribute(lowest_mask, + sched_domain_span(sd)); if (best_cpu < nr_cpu_ids) { rcu_read_unlock(); return best_cpu; @@ -1770,7 +1878,7 @@ static int find_lowest_rq(struct task_struct *task) if (this_cpu != -1) return this_cpu; - cpu = cpumask_any(lowest_mask); + cpu = cpumask_any_distribute(lowest_mask); if (cpu < nr_cpu_ids) return cpu; @@ -1809,11 +1917,15 @@ static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq) * the mean time, task could have * migrated already or had its affinity changed. * Also make sure that it wasn't scheduled on its rq. + * It is possible the task was scheduled, set + * "migrate_disabled" and then got preempted, so we must + * check the task migration disable flag here too. */ if (unlikely(task_rq(task) != rq || - !cpumask_test_cpu(lowest_rq->cpu, task->cpus_ptr) || - task_running(rq, task) || + !cpumask_test_cpu(lowest_rq->cpu, &task->cpus_mask) || + task_on_cpu(rq, task) || !rt_task(task) || + is_migration_disabled(task) || !task_on_rq_queued(task))) { double_unlock_balance(rq, lowest_rq); @@ -1846,6 +1958,7 @@ static struct task_struct *pick_next_pushable_task(struct rq *rq) BUG_ON(rq->cpu != task_cpu(p)); BUG_ON(task_current(rq, p)); + BUG_ON(task_current_donor(rq, p)); BUG_ON(p->nr_cpus_allowed <= 1); BUG_ON(!task_on_rq_queued(p)); @@ -1859,7 +1972,7 @@ static struct task_struct *pick_next_pushable_task(struct rq *rq) * running task can migrate over to a CPU that is running a task * of lesser priority. */ -static int push_rt_task(struct rq *rq) +static int push_rt_task(struct rq *rq, bool pull) { struct task_struct *next_task; struct rq *lowest_rq; @@ -1873,19 +1986,61 @@ static int push_rt_task(struct rq *rq) return 0; retry: - if (WARN_ON(next_task == rq->curr)) - return 0; - /* * It's possible that the next_task slipped in of * higher priority than current. If that's the case * just reschedule current. */ - if (unlikely(next_task->prio < rq->curr->prio)) { + if (unlikely(next_task->prio < rq->donor->prio)) { resched_curr(rq); return 0; } + if (is_migration_disabled(next_task)) { + struct task_struct *push_task = NULL; + int cpu; + + if (!pull || rq->push_busy) + return 0; + + /* + * Invoking find_lowest_rq() on anything but an RT task doesn't + * make sense. Per the above priority check, curr has to + * be of higher priority than next_task, so no need to + * reschedule when bailing out. + * + * Note that the stoppers are masqueraded as SCHED_FIFO + * (cf. sched_set_stop_task()), so we can't rely on rt_task(). + */ + if (rq->donor->sched_class != &rt_sched_class) + return 0; + + cpu = find_lowest_rq(rq->curr); + if (cpu == -1 || cpu == rq->cpu) + return 0; + + /* + * Given we found a CPU with lower priority than @next_task, + * therefore it should be running. However we cannot migrate it + * to this other CPU, instead attempt to push the current + * running task on this CPU away. + */ + push_task = get_push_task(rq); + if (push_task) { + preempt_disable(); + raw_spin_rq_unlock(rq); + stop_one_cpu_nowait(rq->cpu, push_cpu_stop, + push_task, &rq->push_work); + preempt_enable(); + raw_spin_rq_lock(rq); + } + + return 0; + } + + if (WARN_ON(next_task == rq->curr)) + return 0; + /* We might release rq lock */ get_task_struct(next_task); @@ -1924,15 +2079,11 @@ retry: goto retry; } - deactivate_task(rq, next_task, 0); - set_task_cpu(next_task, lowest_rq->cpu); - activate_task(lowest_rq, next_task, 0); - ret = 1; - + move_queued_task_locked(rq, lowest_rq, next_task); resched_curr(lowest_rq); + ret = 1; double_unlock_balance(rq, lowest_rq); - out: put_task_struct(next_task); @@ -1942,7 +2093,7 @@ out: static void push_rt_tasks(struct rq *rq) { /* push_rt_task will return true if it moved an RT */ - while (push_rt_task(rq)) + while (push_rt_task(rq, false)) ; } @@ -1968,14 +2119,14 @@ static void push_rt_tasks(struct rq *rq) * if its the only CPU with multiple RT tasks queued, and a large number * of CPUs scheduling a lower priority task at the same time. * - * Each root domain has its own irq work function that can iterate over + * Each root domain has its own IRQ work function that can iterate over * all CPUs with RT overloaded tasks. Since all CPUs with overloaded RT - * tassk must be checked if there's one or many CPUs that are lowering - * their priority, there's a single irq work iterator that will try to + * task must be checked if there's one or many CPUs that are lowering + * their priority, there's a single IRQ work iterator that will try to * push off RT tasks that are waiting to run. * * When a CPU schedules a lower priority task, it will kick off the - * irq work iterator that will jump to each CPU with overloaded RT tasks. + * IRQ work iterator that will jump to each CPU with overloaded RT tasks. * As it only takes the first CPU that schedules a lower priority task * to start the process, the rto_start variable is incremented and if * the atomic result is one, then that CPU will try to take the rto_lock. @@ -1983,7 +2134,7 @@ static void push_rt_tasks(struct rq *rq) * CPUs scheduling lower priority tasks. * * All CPUs that are scheduling a lower priority task will increment the - * rt_loop_next variable. This will make sure that the irq work iterator + * rt_loop_next variable. This will make sure that the IRQ work iterator * checks all RT overloaded CPUs whenever a CPU schedules a new lower * priority task, even if the iterator is in the middle of a scan. Incrementing * the rt_loop_next will cause the iterator to perform another scan. @@ -2063,7 +2214,7 @@ static void tell_cpu_to_push(struct rq *rq) * The rto_cpu is updated under the lock, if it has a valid CPU * then the IPI is still running and will continue due to the * update to loop_next, and nothing needs to be done here. - * Otherwise it is finishing up and an ipi needs to be sent. + * Otherwise it is finishing up and an IPI needs to be sent. */ if (rq->rd->rto_cpu < 0) cpu = rto_next_cpu(rq->rd); @@ -2094,9 +2245,10 @@ void rto_push_irq_work_func(struct irq_work *work) * When it gets updated, a check is made if a push is possible. */ if (has_pushable_tasks(rq)) { - raw_spin_lock(&rq->lock); - push_rt_tasks(rq); - raw_spin_unlock(&rq->lock); + raw_spin_rq_lock(rq); + while (push_rt_task(rq, true)) + ; + raw_spin_rq_unlock(rq); } raw_spin_lock(&rd->rto_lock); @@ -2120,7 +2272,7 @@ static void pull_rt_task(struct rq *this_rq) { int this_cpu = this_rq->cpu, cpu; bool resched = false; - struct task_struct *p; + struct task_struct *p, *push_task; struct rq *src_rq; int rt_overload_count = rt_overloaded(this_rq); @@ -2167,6 +2319,7 @@ static void pull_rt_task(struct rq *this_rq) * double_lock_balance, and another CPU could * alter this_rq */ + push_task = NULL; double_lock_balance(this_rq, src_rq); /* @@ -2186,19 +2339,20 @@ static void pull_rt_task(struct rq *this_rq) /* * There's a chance that p is higher in priority * than what's currently running on its CPU. - * This is just that p is wakeing up and hasn't + * This is just that p is waking up and hasn't * had a chance to schedule. We only pull * p if it is lower in priority than the * current task on the run queue */ - if (p->prio < src_rq->curr->prio) + if (p->prio < src_rq->donor->prio) goto skip; - resched = true; - - deactivate_task(src_rq, p, 0); - set_task_cpu(p, this_cpu); - activate_task(this_rq, p, 0); + if (is_migration_disabled(p)) { + push_task = get_push_task(src_rq); + } else { + move_queued_task_locked(src_rq, this_rq, p); + resched = true; + } /* * We continue with the search, just in * case there's an even higher prio task @@ -2208,6 +2362,15 @@ static void pull_rt_task(struct rq *this_rq) } skip: double_unlock_balance(this_rq, src_rq); + + if (push_task) { + preempt_disable(); + raw_spin_rq_unlock(this_rq); + stop_one_cpu_nowait(src_rq->cpu, push_cpu_stop, + push_task, &src_rq->push_work); + preempt_enable(); + raw_spin_rq_lock(this_rq); + } } if (resched) @@ -2220,12 +2383,12 @@ skip: */ static void task_woken_rt(struct rq *rq, struct task_struct *p) { - bool need_to_push = !task_running(rq, p) && + bool need_to_push = !task_on_cpu(rq, p) && !test_tsk_need_resched(rq->curr) && p->nr_cpus_allowed > 1 && - (dl_task(rq->curr) || rt_task(rq->curr)) && + (dl_task(rq->donor) || rt_task(rq->donor)) && (rq->curr->nr_cpus_allowed < 2 || - rq->curr->prio <= p->prio); + rq->donor->prio <= p->prio); if (need_to_push) push_rt_tasks(rq); @@ -2291,18 +2454,25 @@ void __init init_sched_rt_class(void) static void switched_to_rt(struct rq *rq, struct task_struct *p) { /* - * If we are already running, then there's nothing - * that needs to be done. But if we are not running - * we may need to preempt the current running task. - * If that current running task is also an RT task + * If we are running, update the avg_rt tracking, as the running time + * will now on be accounted into the latter. + */ + if (task_current(rq, p)) { + update_rt_rq_load_avg(rq_clock_pelt(rq), rq, 0); + return; + } + + /* + * If we are not running we may need to preempt the current + * running task. If that current running task is also an RT task * then see if we can move to another run queue. */ - if (task_on_rq_queued(p) && rq->curr != p) { + 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->curr->prio && cpu_online(cpu_of(rq))) + if (p->prio < rq->donor->prio && cpu_online(cpu_of(rq))) resched_curr(rq); } } @@ -2317,7 +2487,7 @@ prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio) if (!task_on_rq_queued(p)) return; - if (rq->curr == p) { + if (task_current_donor(rq, p)) { #ifdef CONFIG_SMP /* * If our priority decreases while running, we @@ -2343,7 +2513,7 @@ prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio) * greater than the current running task * then reschedule. */ - if (p->prio < rq->curr->prio) + if (p->prio < rq->donor->prio) resched_curr(rq); } } @@ -2394,7 +2564,7 @@ static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued) watchdog(rq, p); /* - * RR tasks need a special form of timeslice management. + * RR tasks need a special form of time-slice management. * FIFO tasks have no timeslices. */ if (p->policy != SCHED_RR) @@ -2429,15 +2599,30 @@ static unsigned int get_rr_interval_rt(struct rq *rq, struct task_struct *task) return 0; } -const struct sched_class rt_sched_class = { - .next = &fair_sched_class, +#ifdef CONFIG_SCHED_CORE +static int task_is_throttled_rt(struct task_struct *p, int cpu) +{ + struct rt_rq *rt_rq; + +#ifdef CONFIG_RT_GROUP_SCHED + rt_rq = task_group(p)->rt_rq[cpu]; +#else + rt_rq = &cpu_rq(cpu)->rt; +#endif + + return rt_rq_throttled(rt_rq); +} +#endif + +DEFINE_SCHED_CLASS(rt) = { + .enqueue_task = enqueue_task_rt, .dequeue_task = dequeue_task_rt, .yield_task = yield_task_rt, - .check_preempt_curr = check_preempt_curr_rt, + .wakeup_preempt = wakeup_preempt_rt, - .pick_next_task = pick_next_task_rt, + .pick_task = pick_task_rt, .put_prev_task = put_prev_task_rt, .set_next_task = set_next_task_rt, @@ -2449,6 +2634,7 @@ const struct sched_class rt_sched_class = { .rq_offline = rq_offline_rt, .task_woken = task_woken_rt, .switched_from = switched_from_rt, + .find_lock_rq = find_lock_lowest_rq, #endif .task_tick = task_tick_rt, @@ -2460,6 +2646,10 @@ const struct sched_class rt_sched_class = { .update_curr = update_curr_rt, +#ifdef CONFIG_SCHED_CORE + .task_is_throttled = task_is_throttled_rt, +#endif + #ifdef CONFIG_UCLAMP_TASK .uclamp_enabled = 1, #endif @@ -2664,6 +2854,7 @@ long sched_group_rt_period(struct task_group *tg) return rt_period_us; } +#ifdef CONFIG_SYSCTL static int sched_rt_global_constraints(void) { int ret = 0; @@ -2674,10 +2865,11 @@ static int sched_rt_global_constraints(void) return ret; } +#endif /* CONFIG_SYSCTL */ int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk) { - /* Don't accept realtime tasks when there is no way for them to run */ + /* Don't accept real-time tasks when there is no way for them to run */ if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0) return 0; @@ -2685,30 +2877,18 @@ int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk) } #else /* !CONFIG_RT_GROUP_SCHED */ + +#ifdef CONFIG_SYSCTL static int sched_rt_global_constraints(void) { - unsigned long flags; - int i; - - raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); - for_each_possible_cpu(i) { - struct rt_rq *rt_rq = &cpu_rq(i)->rt; - - raw_spin_lock(&rt_rq->rt_runtime_lock); - rt_rq->rt_runtime = global_rt_runtime(); - raw_spin_unlock(&rt_rq->rt_runtime_lock); - } - raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags); - return 0; } +#endif /* CONFIG_SYSCTL */ #endif /* CONFIG_RT_GROUP_SCHED */ +#ifdef CONFIG_SYSCTL static int sched_rt_global_validate(void) { - if (sysctl_sched_rt_period <= 0) - return -EINVAL; - if ((sysctl_sched_rt_runtime != RUNTIME_INF) && ((sysctl_sched_rt_runtime > sysctl_sched_rt_period) || ((u64)sysctl_sched_rt_runtime * @@ -2720,11 +2900,9 @@ static int sched_rt_global_validate(void) static void sched_rt_do_global(void) { - def_rt_bandwidth.rt_runtime = global_rt_runtime(); - def_rt_bandwidth.rt_period = ns_to_ktime(global_rt_period()); } -int sched_rt_handler(struct ctl_table *table, int write, void *buffer, +static int sched_rt_handler(const struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos) { int old_period, old_runtime; @@ -2735,7 +2913,7 @@ int sched_rt_handler(struct ctl_table *table, int write, void *buffer, old_period = sysctl_sched_rt_period; old_runtime = sysctl_sched_rt_runtime; - ret = proc_dointvec(table, write, buffer, lenp, ppos); + ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); if (!ret && write) { ret = sched_rt_global_validate(); @@ -2763,7 +2941,7 @@ undo: return ret; } -int sched_rr_handler(struct ctl_table *table, int write, void *buffer, +static int sched_rr_handler(const struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos) { int ret; @@ -2773,17 +2951,21 @@ int sched_rr_handler(struct ctl_table *table, int write, void *buffer, ret = proc_dointvec(table, write, buffer, lenp, ppos); /* * Make sure that internally we keep jiffies. - * Also, writing zero resets the timeslice to default: + * Also, writing zero resets the time-slice to default: */ if (!ret && write) { sched_rr_timeslice = sysctl_sched_rr_timeslice <= 0 ? RR_TIMESLICE : msecs_to_jiffies(sysctl_sched_rr_timeslice); + + if (sysctl_sched_rr_timeslice <= 0) + sysctl_sched_rr_timeslice = jiffies_to_msecs(RR_TIMESLICE); } mutex_unlock(&mutex); return ret; } +#endif /* CONFIG_SYSCTL */ #ifdef CONFIG_SCHED_DEBUG void print_rt_stats(struct seq_file *m, int cpu) |