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-rw-r--r--kernel/sched/deadline.c119
1 files changed, 96 insertions, 23 deletions
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 504d2f51b0d6..3862a28cd05d 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -54,15 +54,49 @@ static inline struct dl_bw *dl_bw_of(int i)
static inline int dl_bw_cpus(int i)
{
struct root_domain *rd = cpu_rq(i)->rd;
- int cpus = 0;
+ int cpus;
RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held(),
"sched RCU must be held");
+
+ if (cpumask_subset(rd->span, cpu_active_mask))
+ return cpumask_weight(rd->span);
+
+ cpus = 0;
+
for_each_cpu_and(i, rd->span, cpu_active_mask)
cpus++;
return cpus;
}
+
+static inline unsigned long __dl_bw_capacity(int i)
+{
+ struct root_domain *rd = cpu_rq(i)->rd;
+ unsigned long cap = 0;
+
+ RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held(),
+ "sched RCU must be held");
+
+ for_each_cpu_and(i, rd->span, cpu_active_mask)
+ cap += capacity_orig_of(i);
+
+ return cap;
+}
+
+/*
+ * XXX Fix: If 'rq->rd == def_root_domain' perform AC against capacity
+ * of the CPU the task is running on rather rd's \Sum CPU capacity.
+ */
+static inline unsigned long dl_bw_capacity(int i)
+{
+ if (!static_branch_unlikely(&sched_asym_cpucapacity) &&
+ capacity_orig_of(i) == SCHED_CAPACITY_SCALE) {
+ return dl_bw_cpus(i) << SCHED_CAPACITY_SHIFT;
+ } else {
+ return __dl_bw_capacity(i);
+ }
+}
#else
static inline struct dl_bw *dl_bw_of(int i)
{
@@ -73,6 +107,11 @@ static inline int dl_bw_cpus(int i)
{
return 1;
}
+
+static inline unsigned long dl_bw_capacity(int i)
+{
+ return SCHED_CAPACITY_SCALE;
+}
#endif
static inline
@@ -1098,7 +1137,7 @@ void init_dl_task_timer(struct sched_dl_entity *dl_se)
* cannot use the runtime, and so it replenishes the task. This rule
* works fine for implicit deadline tasks (deadline == period), and the
* CBS was designed for implicit deadline tasks. However, a task with
- * constrained deadline (deadine < period) might be awakened after the
+ * constrained deadline (deadline < period) might be awakened after the
* deadline, but before the next period. In this case, replenishing the
* task would allow it to run for runtime / deadline. As in this case
* deadline < period, CBS enables a task to run for more than the
@@ -1604,6 +1643,7 @@ static int
select_task_rq_dl(struct task_struct *p, int cpu, int sd_flag, int flags)
{
struct task_struct *curr;
+ bool select_rq;
struct rq *rq;
if (sd_flag != SD_BALANCE_WAKE)
@@ -1623,10 +1663,19 @@ select_task_rq_dl(struct task_struct *p, int cpu, int sd_flag, int flags)
* other hand, if it has a shorter deadline, we
* try to make it stay here, it might be important.
*/
- if (unlikely(dl_task(curr)) &&
- (curr->nr_cpus_allowed < 2 ||
- !dl_entity_preempt(&p->dl, &curr->dl)) &&
- (p->nr_cpus_allowed > 1)) {
+ select_rq = unlikely(dl_task(curr)) &&
+ (curr->nr_cpus_allowed < 2 ||
+ !dl_entity_preempt(&p->dl, &curr->dl)) &&
+ p->nr_cpus_allowed > 1;
+
+ /*
+ * Take the capacity of the CPU into account to
+ * ensure it fits the requirement of the task.
+ */
+ if (static_branch_unlikely(&sched_asym_cpucapacity))
+ select_rq |= !dl_task_fits_capacity(p, cpu);
+
+ if (select_rq) {
int target = find_later_rq(p);
if (target != -1 &&
@@ -2430,8 +2479,8 @@ static void prio_changed_dl(struct rq *rq, struct task_struct *p,
}
}
-const struct sched_class dl_sched_class = {
- .next = &rt_sched_class,
+const struct sched_class dl_sched_class
+ __attribute__((section("__dl_sched_class"))) = {
.enqueue_task = enqueue_task_dl,
.dequeue_task = dequeue_task_dl,
.yield_task = yield_task_dl,
@@ -2551,11 +2600,12 @@ void sched_dl_do_global(void)
int sched_dl_overflow(struct task_struct *p, int policy,
const struct sched_attr *attr)
{
- struct dl_bw *dl_b = dl_bw_of(task_cpu(p));
u64 period = attr->sched_period ?: attr->sched_deadline;
u64 runtime = attr->sched_runtime;
u64 new_bw = dl_policy(policy) ? to_ratio(period, runtime) : 0;
- int cpus, err = -1;
+ int cpus, err = -1, cpu = task_cpu(p);
+ struct dl_bw *dl_b = dl_bw_of(cpu);
+ unsigned long cap;
if (attr->sched_flags & SCHED_FLAG_SUGOV)
return 0;
@@ -2570,15 +2620,17 @@ int sched_dl_overflow(struct task_struct *p, int policy,
* allocated bandwidth of the container.
*/
raw_spin_lock(&dl_b->lock);
- cpus = dl_bw_cpus(task_cpu(p));
+ cpus = dl_bw_cpus(cpu);
+ cap = dl_bw_capacity(cpu);
+
if (dl_policy(policy) && !task_has_dl_policy(p) &&
- !__dl_overflow(dl_b, cpus, 0, new_bw)) {
+ !__dl_overflow(dl_b, cap, 0, new_bw)) {
if (hrtimer_active(&p->dl.inactive_timer))
__dl_sub(dl_b, p->dl.dl_bw, cpus);
__dl_add(dl_b, new_bw, cpus);
err = 0;
} else if (dl_policy(policy) && task_has_dl_policy(p) &&
- !__dl_overflow(dl_b, cpus, p->dl.dl_bw, new_bw)) {
+ !__dl_overflow(dl_b, cap, p->dl.dl_bw, new_bw)) {
/*
* XXX this is slightly incorrect: when the task
* utilization decreases, we should delay the total
@@ -2635,6 +2687,14 @@ void __getparam_dl(struct task_struct *p, struct sched_attr *attr)
}
/*
+ * Default limits for DL period; on the top end we guard against small util
+ * tasks still getting rediculous long effective runtimes, on the bottom end we
+ * guard against timer DoS.
+ */
+unsigned int sysctl_sched_dl_period_max = 1 << 22; /* ~4 seconds */
+unsigned int sysctl_sched_dl_period_min = 100; /* 100 us */
+
+/*
* This function validates the new parameters of a -deadline task.
* We ask for the deadline not being zero, and greater or equal
* than the runtime, as well as the period of being zero or
@@ -2646,6 +2706,8 @@ void __getparam_dl(struct task_struct *p, struct sched_attr *attr)
*/
bool __checkparam_dl(const struct sched_attr *attr)
{
+ u64 period, max, min;
+
/* special dl tasks don't actually use any parameter */
if (attr->sched_flags & SCHED_FLAG_SUGOV)
return true;
@@ -2669,12 +2731,21 @@ bool __checkparam_dl(const struct sched_attr *attr)
attr->sched_period & (1ULL << 63))
return false;
+ period = attr->sched_period;
+ if (!period)
+ period = attr->sched_deadline;
+
/* runtime <= deadline <= period (if period != 0) */
- if ((attr->sched_period != 0 &&
- attr->sched_period < attr->sched_deadline) ||
+ if (period < attr->sched_deadline ||
attr->sched_deadline < attr->sched_runtime)
return false;
+ max = (u64)READ_ONCE(sysctl_sched_dl_period_max) * NSEC_PER_USEC;
+ min = (u64)READ_ONCE(sysctl_sched_dl_period_min) * NSEC_PER_USEC;
+
+ if (period < min || period > max)
+ return false;
+
return true;
}
@@ -2692,6 +2763,7 @@ void __dl_clear_params(struct task_struct *p)
dl_se->dl_bw = 0;
dl_se->dl_density = 0;
+ dl_se->dl_boosted = 0;
dl_se->dl_throttled = 0;
dl_se->dl_yielded = 0;
dl_se->dl_non_contending = 0;
@@ -2714,19 +2786,19 @@ bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr)
#ifdef CONFIG_SMP
int dl_task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed)
{
+ unsigned long flags, cap;
unsigned int dest_cpu;
struct dl_bw *dl_b;
bool overflow;
- int cpus, ret;
- unsigned long flags;
+ int ret;
dest_cpu = cpumask_any_and(cpu_active_mask, cs_cpus_allowed);
rcu_read_lock_sched();
dl_b = dl_bw_of(dest_cpu);
raw_spin_lock_irqsave(&dl_b->lock, flags);
- cpus = dl_bw_cpus(dest_cpu);
- overflow = __dl_overflow(dl_b, cpus, 0, p->dl.dl_bw);
+ cap = dl_bw_capacity(dest_cpu);
+ overflow = __dl_overflow(dl_b, cap, 0, p->dl.dl_bw);
if (overflow) {
ret = -EBUSY;
} else {
@@ -2736,6 +2808,8 @@ int dl_task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allo
* We will free resources in the source root_domain
* later on (see set_cpus_allowed_dl()).
*/
+ int cpus = dl_bw_cpus(dest_cpu);
+
__dl_add(dl_b, p->dl.dl_bw, cpus);
ret = 0;
}
@@ -2768,16 +2842,15 @@ int dl_cpuset_cpumask_can_shrink(const struct cpumask *cur,
bool dl_cpu_busy(unsigned int cpu)
{
- unsigned long flags;
+ unsigned long flags, cap;
struct dl_bw *dl_b;
bool overflow;
- int cpus;
rcu_read_lock_sched();
dl_b = dl_bw_of(cpu);
raw_spin_lock_irqsave(&dl_b->lock, flags);
- cpus = dl_bw_cpus(cpu);
- overflow = __dl_overflow(dl_b, cpus, 0, 0);
+ cap = dl_bw_capacity(cpu);
+ overflow = __dl_overflow(dl_b, cap, 0, 0);
raw_spin_unlock_irqrestore(&dl_b->lock, flags);
rcu_read_unlock_sched();