diff options
Diffstat (limited to 'kernel/sched/deadline.c')
| -rw-r--r-- | kernel/sched/deadline.c | 121 |
1 files changed, 90 insertions, 31 deletions
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index d94f2ed6d1f4..38e4537790af 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -26,7 +26,7 @@ static unsigned int sysctl_sched_dl_period_max = 1 << 22; /* ~4 seconds */ static unsigned int sysctl_sched_dl_period_min = 100; /* 100 us */ #ifdef CONFIG_SYSCTL -static struct ctl_table sched_dl_sysctls[] = { +static const struct ctl_table sched_dl_sysctls[] = { { .procname = "sched_deadline_period_max_us", .data = &sysctl_sched_dl_period_max, @@ -342,6 +342,29 @@ static void dl_rq_change_utilization(struct rq *rq, struct sched_dl_entity *dl_s __add_rq_bw(new_bw, &rq->dl); } +static __always_inline +void cancel_dl_timer(struct sched_dl_entity *dl_se, struct hrtimer *timer) +{ + /* + * If the timer callback was running (hrtimer_try_to_cancel == -1), + * it will eventually call put_task_struct(). + */ + if (hrtimer_try_to_cancel(timer) == 1 && !dl_server(dl_se)) + put_task_struct(dl_task_of(dl_se)); +} + +static __always_inline +void cancel_replenish_timer(struct sched_dl_entity *dl_se) +{ + cancel_dl_timer(dl_se, &dl_se->dl_timer); +} + +static __always_inline +void cancel_inactive_timer(struct sched_dl_entity *dl_se) +{ + cancel_dl_timer(dl_se, &dl_se->inactive_timer); +} + static void dl_change_utilization(struct task_struct *p, u64 new_bw) { WARN_ON_ONCE(p->dl.flags & SCHED_FLAG_SUGOV); @@ -495,10 +518,7 @@ static void task_contending(struct sched_dl_entity *dl_se, int flags) * will not touch the rq's active utilization, * so we are still safe. */ - if (hrtimer_try_to_cancel(&dl_se->inactive_timer) == 1) { - if (!dl_server(dl_se)) - put_task_struct(dl_task_of(dl_se)); - } + cancel_inactive_timer(dl_se); } else { /* * Since "dl_non_contending" is not set, the @@ -2115,13 +2135,8 @@ static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags) * The replenish timer needs to be canceled. No * problem if it fires concurrently: boosted threads * are ignored in dl_task_timer(). - * - * If the timer callback was running (hrtimer_try_to_cancel == -1), - * it will eventually call put_task_struct(). */ - if (hrtimer_try_to_cancel(&p->dl.dl_timer) == 1 && - !dl_server(&p->dl)) - put_task_struct(p); + cancel_replenish_timer(&p->dl); p->dl.dl_throttled = 0; } } else if (!dl_prio(p->normal_prio)) { @@ -2289,8 +2304,7 @@ static void migrate_task_rq_dl(struct task_struct *p, int new_cpu __maybe_unused * will not touch the rq's active utilization, * so we are still safe. */ - if (hrtimer_try_to_cancel(&p->dl.inactive_timer) == 1) - put_task_struct(p); + cancel_inactive_timer(&p->dl); } sub_rq_bw(&p->dl, &rq->dl); rq_unlock(rq, &rf); @@ -2506,16 +2520,13 @@ static struct task_struct *pick_earliest_pushable_dl_task(struct rq *rq, int cpu return NULL; next_node = rb_first_cached(&rq->dl.pushable_dl_tasks_root); - -next_node: - if (next_node) { + while (next_node) { p = __node_2_pdl(next_node); if (task_is_pushable(rq, p, cpu)) return p; next_node = rb_next(next_node); - goto next_node; } return NULL; @@ -2964,11 +2975,22 @@ void dl_add_task_root_domain(struct task_struct *p) void dl_clear_root_domain(struct root_domain *rd) { - unsigned long flags; + int i; - raw_spin_lock_irqsave(&rd->dl_bw.lock, flags); + guard(raw_spinlock_irqsave)(&rd->dl_bw.lock); rd->dl_bw.total_bw = 0; - raw_spin_unlock_irqrestore(&rd->dl_bw.lock, flags); + + /* + * dl_server bandwidth is only restored when CPUs are attached to root + * domains (after domains are created or CPUs moved back to the + * default root doamin). + */ + for_each_cpu(i, rd->span) { + struct sched_dl_entity *dl_se = &cpu_rq(i)->fair_server; + + if (dl_server(dl_se) && cpu_active(i)) + rd->dl_bw.total_bw += dl_se->dl_bw; + } } #endif /* CONFIG_SMP */ @@ -3029,8 +3051,7 @@ static void switched_from_dl(struct rq *rq, struct task_struct *p) */ static void switched_to_dl(struct rq *rq, struct task_struct *p) { - if (hrtimer_try_to_cancel(&p->dl.inactive_timer) == 1) - put_task_struct(p); + cancel_inactive_timer(&p->dl); /* * In case a task is setscheduled to SCHED_DEADLINE we need to keep @@ -3453,29 +3474,31 @@ int dl_cpuset_cpumask_can_shrink(const struct cpumask *cur, } enum dl_bw_request { - dl_bw_req_check_overflow = 0, + dl_bw_req_deactivate = 0, dl_bw_req_alloc, dl_bw_req_free }; static int dl_bw_manage(enum dl_bw_request req, int cpu, u64 dl_bw) { - unsigned long flags; + unsigned long flags, cap; struct dl_bw *dl_b; bool overflow = 0; + u64 fair_server_bw = 0; rcu_read_lock_sched(); dl_b = dl_bw_of(cpu); raw_spin_lock_irqsave(&dl_b->lock, flags); - if (req == dl_bw_req_free) { + cap = dl_bw_capacity(cpu); + switch (req) { + case dl_bw_req_free: __dl_sub(dl_b, dl_bw, dl_bw_cpus(cpu)); - } else { - unsigned long cap = dl_bw_capacity(cpu); - + break; + case dl_bw_req_alloc: overflow = __dl_overflow(dl_b, cap, 0, dl_bw); - if (req == dl_bw_req_alloc && !overflow) { + if (!overflow) { /* * We reserve space in the destination * root_domain, as we can't fail after this point. @@ -3484,6 +3507,42 @@ static int dl_bw_manage(enum dl_bw_request req, int cpu, u64 dl_bw) */ __dl_add(dl_b, dl_bw, dl_bw_cpus(cpu)); } + break; + case dl_bw_req_deactivate: + /* + * cpu is not off yet, but we need to do the math by + * considering it off already (i.e., what would happen if we + * turn cpu off?). + */ + cap -= arch_scale_cpu_capacity(cpu); + + /* + * cpu is going offline and NORMAL tasks will be moved away + * from it. We can thus discount dl_server bandwidth + * contribution as it won't need to be servicing tasks after + * the cpu is off. + */ + if (cpu_rq(cpu)->fair_server.dl_server) + fair_server_bw = cpu_rq(cpu)->fair_server.dl_bw; + + /* + * Not much to check if no DEADLINE bandwidth is present. + * dl_servers we can discount, as tasks will be moved out the + * offlined CPUs anyway. + */ + if (dl_b->total_bw - fair_server_bw > 0) { + /* + * Leaving at least one CPU for DEADLINE tasks seems a + * wise thing to do. As said above, cpu is not offline + * yet, so account for that. + */ + if (dl_bw_cpus(cpu) - 1) + overflow = __dl_overflow(dl_b, cap, fair_server_bw, 0); + else + overflow = 1; + } + + break; } raw_spin_unlock_irqrestore(&dl_b->lock, flags); @@ -3492,9 +3551,9 @@ static int dl_bw_manage(enum dl_bw_request req, int cpu, u64 dl_bw) return overflow ? -EBUSY : 0; } -int dl_bw_check_overflow(int cpu) +int dl_bw_deactivate(int cpu) { - return dl_bw_manage(dl_bw_req_check_overflow, cpu, 0); + return dl_bw_manage(dl_bw_req_deactivate, cpu, 0); } int dl_bw_alloc(int cpu, u64 dl_bw) |