summaryrefslogtreecommitdiffstats
path: root/kernel/sched.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2011-10-26 17:08:43 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2011-10-26 17:08:43 +0200
commit8a4a8918ed6e4a361f4df19f199bbc2d0a89a46c (patch)
treed76974986aaaa8549baf2d6a106fa6cb60d64b88 /kernel/sched.c
parent8686a0e200419322654a75155e2e6f80346a1297 (diff)
parent540f41edc15473ca3b2876de72646546ae101374 (diff)
downloadlinux-8a4a8918ed6e4a361f4df19f199bbc2d0a89a46c.tar.bz2
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (46 commits) llist: Add back llist_add_batch() and llist_del_first() prototypes sched: Don't use tasklist_lock for debug prints sched: Warn on rt throttling sched: Unify the ->cpus_allowed mask copy sched: Wrap scheduler p->cpus_allowed access sched: Request for idle balance during nohz idle load balance sched: Use resched IPI to kick off the nohz idle balance sched: Fix idle_cpu() llist: Remove cpu_relax() usage in cmpxchg loops sched: Convert to struct llist llist: Add llist_next() irq_work: Use llist in the struct irq_work logic llist: Return whether list is empty before adding in llist_add() llist: Move cpu_relax() to after the cmpxchg() llist: Remove the platform-dependent NMI checks llist: Make some llist functions inline sched, tracing: Show PREEMPT_ACTIVE state in trace_sched_switch sched: Remove redundant test in check_preempt_tick() sched: Add documentation for bandwidth control sched: Return unused runtime on group dequeue ...
Diffstat (limited to 'kernel/sched.c')
-rw-r--r--kernel/sched.c666
1 files changed, 549 insertions, 117 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index 03ad0113801a..d87c6e5d4e8c 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -196,10 +196,28 @@ static inline int rt_bandwidth_enabled(void)
return sysctl_sched_rt_runtime >= 0;
}
-static void start_rt_bandwidth(struct rt_bandwidth *rt_b)
+static void start_bandwidth_timer(struct hrtimer *period_timer, ktime_t period)
{
- ktime_t now;
+ unsigned long delta;
+ ktime_t soft, hard, now;
+
+ for (;;) {
+ if (hrtimer_active(period_timer))
+ break;
+
+ now = hrtimer_cb_get_time(period_timer);
+ hrtimer_forward(period_timer, now, period);
+ soft = hrtimer_get_softexpires(period_timer);
+ hard = hrtimer_get_expires(period_timer);
+ delta = ktime_to_ns(ktime_sub(hard, soft));
+ __hrtimer_start_range_ns(period_timer, soft, delta,
+ HRTIMER_MODE_ABS_PINNED, 0);
+ }
+}
+
+static void start_rt_bandwidth(struct rt_bandwidth *rt_b)
+{
if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)
return;
@@ -207,22 +225,7 @@ static void start_rt_bandwidth(struct rt_bandwidth *rt_b)
return;
raw_spin_lock(&rt_b->rt_runtime_lock);
- for (;;) {
- unsigned long delta;
- ktime_t soft, hard;
-
- if (hrtimer_active(&rt_b->rt_period_timer))
- break;
-
- now = hrtimer_cb_get_time(&rt_b->rt_period_timer);
- hrtimer_forward(&rt_b->rt_period_timer, now, rt_b->rt_period);
-
- soft = hrtimer_get_softexpires(&rt_b->rt_period_timer);
- hard = hrtimer_get_expires(&rt_b->rt_period_timer);
- delta = ktime_to_ns(ktime_sub(hard, soft));
- __hrtimer_start_range_ns(&rt_b->rt_period_timer, soft, delta,
- HRTIMER_MODE_ABS_PINNED, 0);
- }
+ start_bandwidth_timer(&rt_b->rt_period_timer, rt_b->rt_period);
raw_spin_unlock(&rt_b->rt_runtime_lock);
}
@@ -247,6 +250,24 @@ struct cfs_rq;
static LIST_HEAD(task_groups);
+struct cfs_bandwidth {
+#ifdef CONFIG_CFS_BANDWIDTH
+ raw_spinlock_t lock;
+ ktime_t period;
+ u64 quota, runtime;
+ s64 hierarchal_quota;
+ u64 runtime_expires;
+
+ int idle, timer_active;
+ struct hrtimer period_timer, slack_timer;
+ struct list_head throttled_cfs_rq;
+
+ /* statistics */
+ int nr_periods, nr_throttled;
+ u64 throttled_time;
+#endif
+};
+
/* task group related information */
struct task_group {
struct cgroup_subsys_state css;
@@ -278,6 +299,8 @@ struct task_group {
#ifdef CONFIG_SCHED_AUTOGROUP
struct autogroup *autogroup;
#endif
+
+ struct cfs_bandwidth cfs_bandwidth;
};
/* task_group_lock serializes the addition/removal of task groups */
@@ -311,7 +334,7 @@ struct task_group root_task_group;
/* CFS-related fields in a runqueue */
struct cfs_rq {
struct load_weight load;
- unsigned long nr_running;
+ unsigned long nr_running, h_nr_running;
u64 exec_clock;
u64 min_vruntime;
@@ -377,9 +400,120 @@ struct cfs_rq {
unsigned long load_contribution;
#endif
+#ifdef CONFIG_CFS_BANDWIDTH
+ int runtime_enabled;
+ u64 runtime_expires;
+ s64 runtime_remaining;
+
+ u64 throttled_timestamp;
+ int throttled, throttle_count;
+ struct list_head throttled_list;
+#endif
#endif
};
+#ifdef CONFIG_FAIR_GROUP_SCHED
+#ifdef CONFIG_CFS_BANDWIDTH
+static inline struct cfs_bandwidth *tg_cfs_bandwidth(struct task_group *tg)
+{
+ return &tg->cfs_bandwidth;
+}
+
+static inline u64 default_cfs_period(void);
+static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun);
+static void do_sched_cfs_slack_timer(struct cfs_bandwidth *cfs_b);
+
+static enum hrtimer_restart sched_cfs_slack_timer(struct hrtimer *timer)
+{
+ struct cfs_bandwidth *cfs_b =
+ container_of(timer, struct cfs_bandwidth, slack_timer);
+ do_sched_cfs_slack_timer(cfs_b);
+
+ return HRTIMER_NORESTART;
+}
+
+static enum hrtimer_restart sched_cfs_period_timer(struct hrtimer *timer)
+{
+ struct cfs_bandwidth *cfs_b =
+ container_of(timer, struct cfs_bandwidth, period_timer);
+ ktime_t now;
+ int overrun;
+ int idle = 0;
+
+ for (;;) {
+ now = hrtimer_cb_get_time(timer);
+ overrun = hrtimer_forward(timer, now, cfs_b->period);
+
+ if (!overrun)
+ break;
+
+ idle = do_sched_cfs_period_timer(cfs_b, overrun);
+ }
+
+ return idle ? HRTIMER_NORESTART : HRTIMER_RESTART;
+}
+
+static void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b)
+{
+ raw_spin_lock_init(&cfs_b->lock);
+ cfs_b->runtime = 0;
+ cfs_b->quota = RUNTIME_INF;
+ cfs_b->period = ns_to_ktime(default_cfs_period());
+
+ INIT_LIST_HEAD(&cfs_b->throttled_cfs_rq);
+ hrtimer_init(&cfs_b->period_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ cfs_b->period_timer.function = sched_cfs_period_timer;
+ hrtimer_init(&cfs_b->slack_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ cfs_b->slack_timer.function = sched_cfs_slack_timer;
+}
+
+static void init_cfs_rq_runtime(struct cfs_rq *cfs_rq)
+{
+ cfs_rq->runtime_enabled = 0;
+ INIT_LIST_HEAD(&cfs_rq->throttled_list);
+}
+
+/* requires cfs_b->lock, may release to reprogram timer */
+static void __start_cfs_bandwidth(struct cfs_bandwidth *cfs_b)
+{
+ /*
+ * The timer may be active because we're trying to set a new bandwidth
+ * period or because we're racing with the tear-down path
+ * (timer_active==0 becomes visible before the hrtimer call-back
+ * terminates). In either case we ensure that it's re-programmed
+ */
+ while (unlikely(hrtimer_active(&cfs_b->period_timer))) {
+ raw_spin_unlock(&cfs_b->lock);
+ /* ensure cfs_b->lock is available while we wait */
+ hrtimer_cancel(&cfs_b->period_timer);
+
+ raw_spin_lock(&cfs_b->lock);
+ /* if someone else restarted the timer then we're done */
+ if (cfs_b->timer_active)
+ return;
+ }
+
+ cfs_b->timer_active = 1;
+ start_bandwidth_timer(&cfs_b->period_timer, cfs_b->period);
+}
+
+static void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b)
+{
+ hrtimer_cancel(&cfs_b->period_timer);
+ hrtimer_cancel(&cfs_b->slack_timer);
+}
+#else
+static void init_cfs_rq_runtime(struct cfs_rq *cfs_rq) {}
+static void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {}
+static void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {}
+
+static inline struct cfs_bandwidth *tg_cfs_bandwidth(struct task_group *tg)
+{
+ return NULL;
+}
+#endif /* CONFIG_CFS_BANDWIDTH */
+#endif /* CONFIG_FAIR_GROUP_SCHED */
+
/* Real-Time classes' related field in a runqueue: */
struct rt_rq {
struct rt_prio_array active;
@@ -510,7 +644,7 @@ struct rq {
unsigned long cpu_power;
- unsigned char idle_at_tick;
+ unsigned char idle_balance;
/* For active balancing */
int post_schedule;
int active_balance;
@@ -520,8 +654,6 @@ struct rq {
int cpu;
int online;
- unsigned long avg_load_per_task;
-
u64 rt_avg;
u64 age_stamp;
u64 idle_stamp;
@@ -570,7 +702,7 @@ struct rq {
#endif
#ifdef CONFIG_SMP
- struct task_struct *wake_list;
+ struct llist_head wake_list;
#endif
};
@@ -1272,6 +1404,18 @@ void wake_up_idle_cpu(int cpu)
smp_send_reschedule(cpu);
}
+static inline bool got_nohz_idle_kick(void)
+{
+ return idle_cpu(smp_processor_id()) && this_rq()->nohz_balance_kick;
+}
+
+#else /* CONFIG_NO_HZ */
+
+static inline bool got_nohz_idle_kick(void)
+{
+ return false;
+}
+
#endif /* CONFIG_NO_HZ */
static u64 sched_avg_period(void)
@@ -1471,24 +1615,28 @@ static inline void dec_cpu_load(struct rq *rq, unsigned long load)
update_load_sub(&rq->load, load);
}
-#if (defined(CONFIG_SMP) && defined(CONFIG_FAIR_GROUP_SCHED)) || defined(CONFIG_RT_GROUP_SCHED)
+#if defined(CONFIG_RT_GROUP_SCHED) || (defined(CONFIG_FAIR_GROUP_SCHED) && \
+ (defined(CONFIG_SMP) || defined(CONFIG_CFS_BANDWIDTH)))
typedef int (*tg_visitor)(struct task_group *, void *);
/*
- * Iterate the full tree, calling @down when first entering a node and @up when
- * leaving it for the final time.
+ * Iterate task_group tree rooted at *from, calling @down when first entering a
+ * node and @up when leaving it for the final time.
+ *
+ * Caller must hold rcu_lock or sufficient equivalent.
*/
-static int walk_tg_tree(tg_visitor down, tg_visitor up, void *data)
+static int walk_tg_tree_from(struct task_group *from,
+ tg_visitor down, tg_visitor up, void *data)
{
struct task_group *parent, *child;
int ret;
- rcu_read_lock();
- parent = &root_task_group;
+ parent = from;
+
down:
ret = (*down)(parent, data);
if (ret)
- goto out_unlock;
+ goto out;
list_for_each_entry_rcu(child, &parent->children, siblings) {
parent = child;
goto down;
@@ -1497,19 +1645,29 @@ up:
continue;
}
ret = (*up)(parent, data);
- if (ret)
- goto out_unlock;
+ if (ret || parent == from)
+ goto out;
child = parent;
parent = parent->parent;
if (parent)
goto up;
-out_unlock:
- rcu_read_unlock();
-
+out:
return ret;
}
+/*
+ * Iterate the full tree, calling @down when first entering a node and @up when
+ * leaving it for the final time.
+ *
+ * Caller must hold rcu_lock or sufficient equivalent.
+ */
+
+static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data)
+{
+ return walk_tg_tree_from(&root_task_group, down, up, data);
+}
+
static int tg_nop(struct task_group *tg, void *data)
{
return 0;
@@ -1569,11 +1727,9 @@ static unsigned long cpu_avg_load_per_task(int cpu)
unsigned long nr_running = ACCESS_ONCE(rq->nr_running);
if (nr_running)
- rq->avg_load_per_task = rq->load.weight / nr_running;
- else
- rq->avg_load_per_task = 0;
+ return rq->load.weight / nr_running;
- return rq->avg_load_per_task;
+ return 0;
}
#ifdef CONFIG_PREEMPT
@@ -1806,7 +1962,6 @@ static void activate_task(struct rq *rq, struct task_struct *p, int flags)
rq->nr_uninterruptible--;
enqueue_task(rq, p, flags);
- inc_nr_running(rq);
}
/*
@@ -1818,7 +1973,6 @@ static void deactivate_task(struct rq *rq, struct task_struct *p, int flags)
rq->nr_uninterruptible++;
dequeue_task(rq, p, flags);
- dec_nr_running(rq);
}
#ifdef CONFIG_IRQ_TIME_ACCOUNTING
@@ -2390,11 +2544,11 @@ static int select_fallback_rq(int cpu, struct task_struct *p)
/* Look for allowed, online CPU in same node. */
for_each_cpu_and(dest_cpu, nodemask, cpu_active_mask)
- if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed))
+ if (cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p)))
return dest_cpu;
/* Any allowed, online CPU? */
- dest_cpu = cpumask_any_and(&p->cpus_allowed, cpu_active_mask);
+ dest_cpu = cpumask_any_and(tsk_cpus_allowed(p), cpu_active_mask);
if (dest_cpu < nr_cpu_ids)
return dest_cpu;
@@ -2431,7 +2585,7 @@ int select_task_rq(struct task_struct *p, int sd_flags, int wake_flags)
* [ this allows ->select_task() to simply return task_cpu(p) and
* not worry about this generic constraint ]
*/
- if (unlikely(!cpumask_test_cpu(cpu, &p->cpus_allowed) ||
+ if (unlikely(!cpumask_test_cpu(cpu, tsk_cpus_allowed(p)) ||
!cpu_online(cpu)))
cpu = select_fallback_rq(task_cpu(p), p);
@@ -2556,42 +2710,26 @@ static int ttwu_remote(struct task_struct *p, int wake_flags)
}
#ifdef CONFIG_SMP
-static void sched_ttwu_do_pending(struct task_struct *list)
+static void sched_ttwu_pending(void)
{
struct rq *rq = this_rq();
+ struct llist_node *llist = llist_del_all(&rq->wake_list);
+ struct task_struct *p;
raw_spin_lock(&rq->lock);
- while (list) {
- struct task_struct *p = list;
- list = list->wake_entry;
+ while (llist) {
+ p = llist_entry(llist, struct task_struct, wake_entry);
+ llist = llist_next(llist);
ttwu_do_activate(rq, p, 0);
}
raw_spin_unlock(&rq->lock);
}
-#ifdef CONFIG_HOTPLUG_CPU
-
-static void sched_ttwu_pending(void)
-{
- struct rq *rq = this_rq();
- struct task_struct *list = xchg(&rq->wake_list, NULL);
-
- if (!list)
- return;
-
- sched_ttwu_do_pending(list);
-}
-
-#endif /* CONFIG_HOTPLUG_CPU */
-
void scheduler_ipi(void)
{
- struct rq *rq = this_rq();
- struct task_struct *list = xchg(&rq->wake_list, NULL);
-
- if (!list)
+ if (llist_empty(&this_rq()->wake_list) && !got_nohz_idle_kick())
return;
/*
@@ -2608,25 +2746,21 @@ void scheduler_ipi(void)
* somewhat pessimize the simple resched case.
*/
irq_enter();
- sched_ttwu_do_pending(list);
+ sched_ttwu_pending();
+
+ /*
+ * Check if someone kicked us for doing the nohz idle load balance.
+ */
+ if (unlikely(got_nohz_idle_kick() && !need_resched())) {
+ this_rq()->idle_balance = 1;
+ raise_softirq_irqoff(SCHED_SOFTIRQ);
+ }
irq_exit();
}
static void ttwu_queue_remote(struct task_struct *p, int cpu)
{
- struct rq *rq = cpu_rq(cpu);
- struct task_struct *next = rq->wake_list;
-
- for (;;) {
- struct task_struct *old = next;
-
- p->wake_entry = next;
- next = cmpxchg(&rq->wake_list, old, p);
- if (next == old)
- break;
- }
-
- if (!next)
+ if (llist_add(&p->wake_entry, &cpu_rq(cpu)->wake_list))
smp_send_reschedule(cpu);
}
@@ -2848,19 +2982,23 @@ void sched_fork(struct task_struct *p)
p->state = TASK_RUNNING;
/*
+ * Make sure we do not leak PI boosting priority to the child.
+ */
+ p->prio = current->normal_prio;
+
+ /*
* Revert to default priority/policy on fork if requested.
*/
if (unlikely(p->sched_reset_on_fork)) {
- if (p->policy == SCHED_FIFO || p->policy == SCHED_RR) {
+ if (task_has_rt_policy(p)) {
p->policy = SCHED_NORMAL;
- p->normal_prio = p->static_prio;
- }
-
- if (PRIO_TO_NICE(p->static_prio) < 0) {
p->static_prio = NICE_TO_PRIO(0);
- p->normal_prio = p->static_prio;
- set_load_weight(p);
- }
+ p->rt_priority = 0;
+ } else if (PRIO_TO_NICE(p->static_prio) < 0)
+ p->static_prio = NICE_TO_PRIO(0);
+
+ p->prio = p->normal_prio = __normal_prio(p);
+ set_load_weight(p);
/*
* We don't need the reset flag anymore after the fork. It has
@@ -2869,11 +3007,6 @@ void sched_fork(struct task_struct *p)
p->sched_reset_on_fork = 0;
}
- /*
- * Make sure we do not leak PI boosting priority to the child.
- */
- p->prio = current->normal_prio;
-
if (!rt_prio(p->prio))
p->sched_class = &fair_sched_class;
@@ -4116,7 +4249,7 @@ void scheduler_tick(void)
perf_event_task_tick();
#ifdef CONFIG_SMP
- rq->idle_at_tick = idle_cpu(cpu);
+ rq->idle_balance = idle_cpu(cpu);
trigger_load_balance(rq, cpu);
#endif
}
@@ -4240,7 +4373,7 @@ pick_next_task(struct rq *rq)
* Optimization: we know that if all tasks are in
* the fair class we can call that function directly:
*/
- if (likely(rq->nr_running == rq->cfs.nr_running)) {
+ if (likely(rq->nr_running == rq->cfs.h_nr_running)) {
p = fair_sched_class.pick_next_task(rq);
if (likely(p))
return p;
@@ -5026,7 +5159,20 @@ EXPORT_SYMBOL(task_nice);
*/
int idle_cpu(int cpu)
{
- return cpu_curr(cpu) == cpu_rq(cpu)->idle;
+ struct rq *rq = cpu_rq(cpu);
+
+ if (rq->curr != rq->idle)
+ return 0;
+
+ if (rq->nr_running)
+ return 0;
+
+#ifdef CONFIG_SMP
+ if (!llist_empty(&rq->wake_list))
+ return 0;
+#endif
+
+ return 1;
}
/**
@@ -5876,7 +6022,7 @@ void show_state_filter(unsigned long state_filter)
printk(KERN_INFO
" task PC stack pid father\n");
#endif
- read_lock(&tasklist_lock);
+ rcu_read_lock();
do_each_thread(g, p) {
/*
* reset the NMI-timeout, listing all files on a slow
@@ -5892,7 +6038,7 @@ void show_state_filter(unsigned long state_filter)
#ifdef CONFIG_SCHED_DEBUG
sysrq_sched_debug_show();
#endif
- read_unlock(&tasklist_lock);
+ rcu_read_unlock();
/*
* Only show locks if all tasks are dumped:
*/
@@ -6007,10 +6153,9 @@ void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
{
if (p->sched_class && p->sched_class->set_cpus_allowed)
p->sched_class->set_cpus_allowed(p, new_mask);
- else {
- cpumask_copy(&p->cpus_allowed, new_mask);
- p->rt.nr_cpus_allowed = cpumask_weight(new_mask);
- }
+
+ cpumask_copy(&p->cpus_allowed, new_mask);
+ p->rt.nr_cpus_allowed = cpumask_weight(new_mask);
}
/*
@@ -6108,7 +6253,7 @@ static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu)
if (task_cpu(p) != src_cpu)
goto done;
/* Affinity changed (again). */
- if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed))
+ if (!cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p)))
goto fail;
/*
@@ -6189,6 +6334,30 @@ static void calc_global_load_remove(struct rq *rq)
rq->calc_load_active = 0;
}
+#ifdef CONFIG_CFS_BANDWIDTH
+static void unthrottle_offline_cfs_rqs(struct rq *rq)
+{
+ struct cfs_rq *cfs_rq;
+
+ for_each_leaf_cfs_rq(rq, cfs_rq) {
+ struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg);
+
+ if (!cfs_rq->runtime_enabled)
+ continue;
+
+ /*
+ * clock_task is not advancing so we just need to make sure
+ * there's some valid quota amount
+ */
+ cfs_rq->runtime_remaining = cfs_b->quota;
+ if (cfs_rq_throttled(cfs_rq))
+ unthrottle_cfs_rq(cfs_rq);
+ }
+}
+#else
+static void unthrottle_offline_cfs_rqs(struct rq *rq) {}
+#endif
+
/*
* Migrate all tasks from the rq, sleeping tasks will be migrated by
* try_to_wake_up()->select_task_rq().
@@ -6214,6 +6383,9 @@ static void migrate_tasks(unsigned int dead_cpu)
*/
rq->stop = NULL;
+ /* Ensure any throttled groups are reachable by pick_next_task */
+ unthrottle_offline_cfs_rqs(rq);
+
for ( ; ; ) {
/*
* There's this thread running, bail when that's the only
@@ -7957,6 +8129,7 @@ static void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
/* allow initial update_cfs_load() to truncate */
cfs_rq->load_stamp = 1;
#endif
+ init_cfs_rq_runtime(cfs_rq);
tg->cfs_rq[cpu] = cfs_rq;
tg->se[cpu] = se;
@@ -8096,6 +8269,7 @@ void __init sched_init(void)
* We achieve this by letting root_task_group's tasks sit
* directly in rq->cfs (i.e root_task_group->se[] = NULL).
*/
+ init_cfs_bandwidth(&root_task_group.cfs_bandwidth);
init_tg_cfs_entry(&root_task_group, &rq->cfs, NULL, i, NULL);
#endif /* CONFIG_FAIR_GROUP_SCHED */
@@ -8125,7 +8299,6 @@ void __init sched_init(void)
rq_attach_root(rq, &def_root_domain);
#ifdef CONFIG_NO_HZ
rq->nohz_balance_kick = 0;
- init_sched_softirq_csd(&per_cpu(remote_sched_softirq_cb, i));
#endif
#endif
init_rq_hrtick(rq);
@@ -8336,6 +8509,8 @@ static void free_fair_sched_group(struct task_group *tg)
{
int i;
+ destroy_cfs_bandwidth(tg_cfs_bandwidth(tg));
+
for_each_possible_cpu(i) {
if (tg->cfs_rq)
kfree(tg->cfs_rq[i]);
@@ -8363,6 +8538,8 @@ int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
tg->shares = NICE_0_LOAD;
+ init_cfs_bandwidth(tg_cfs_bandwidth(tg));
+
for_each_possible_cpu(i) {
cfs_rq = kzalloc_node(sizeof(struct cfs_rq),
GFP_KERNEL, cpu_to_node(i));
@@ -8638,12 +8815,7 @@ unsigned long sched_group_shares(struct task_group *tg)
}
#endif
-#ifdef CONFIG_RT_GROUP_SCHED
-/*
- * Ensure that the real time constraints are schedulable.
- */
-static DEFINE_MUTEX(rt_constraints_mutex);
-
+#if defined(CONFIG_RT_GROUP_SCHED) || defined(CONFIG_CFS_BANDWIDTH)
static unsigned long to_ratio(u64 period, u64 runtime)
{
if (runtime == RUNTIME_INF)
@@ -8651,6 +8823,13 @@ static unsigned long to_ratio(u64 period, u64 runtime)
return div64_u64(runtime << 20, period);
}
+#endif
+
+#ifdef CONFIG_RT_GROUP_SCHED
+/*
+ * Ensure that the real time constraints are schedulable.
+ */
+static DEFINE_MUTEX(rt_constraints_mutex);
/* Must be called with tasklist_lock held */
static inline int tg_has_rt_tasks(struct task_group *tg)
@@ -8671,7 +8850,7 @@ struct rt_schedulable_data {
u64 rt_runtime;
};
-static int tg_schedulable(struct task_group *tg, void *data)
+static int tg_rt_schedulable(struct task_group *tg, void *data)
{
struct rt_schedulable_data *d = data;
struct task_group *child;
@@ -8729,16 +8908,22 @@ static int tg_schedulable(struct task_group *tg, void *data)
static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime)
{
+ int ret;
+
struct rt_schedulable_data data = {
.tg = tg,
.rt_period = period,
.rt_runtime = runtime,
};
- return walk_tg_tree(tg_schedulable, tg_nop, &data);
+ rcu_read_lock();
+ ret = walk_tg_tree(tg_rt_schedulable, tg_nop, &data);
+ rcu_read_unlock();
+
+ return ret;
}
-static int tg_set_bandwidth(struct task_group *tg,
+static int tg_set_rt_bandwidth(struct task_group *tg,
u64 rt_period, u64 rt_runtime)
{
int i, err = 0;
@@ -8777,7 +8962,7 @@ int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us)
if (rt_runtime_us < 0)
rt_runtime = RUNTIME_INF;
- return tg_set_bandwidth(tg, rt_period, rt_runtime);
+ return tg_set_rt_bandwidth(tg, rt_period, rt_runtime);
}
long sched_group_rt_runtime(struct task_group *tg)
@@ -8802,7 +8987,7 @@ int sched_group_set_rt_period(struct task_group *tg, long rt_period_us)
if (rt_period == 0)
return -EINVAL;
- return tg_set_bandwidth(tg, rt_period, rt_runtime);
+ return tg_set_rt_bandwidth(tg, rt_period, rt_runtime);
}
long sched_group_rt_period(struct task_group *tg)
@@ -8992,6 +9177,238 @@ static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft)
return (u64) scale_load_down(tg->shares);
}
+
+#ifdef CONFIG_CFS_BANDWIDTH
+static DEFINE_MUTEX(cfs_constraints_mutex);
+
+const u64 max_cfs_quota_period = 1 * NSEC_PER_SEC; /* 1s */
+const u64 min_cfs_quota_period = 1 * NSEC_PER_MSEC; /* 1ms */
+
+static int __cfs_schedulable(struct task_group *tg, u64 period, u64 runtime);
+
+static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota)
+{
+ int i, ret = 0, runtime_enabled;
+ struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(tg);
+
+ if (tg == &root_task_group)
+ return -EINVAL;
+
+ /*
+ * Ensure we have at some amount of bandwidth every period. This is
+ * to prevent reaching a state of large arrears when throttled via
+ * entity_tick() resulting in prolonged exit starvation.
+ */
+ if (quota < min_cfs_quota_period || period < min_cfs_quota_period)
+ return -EINVAL;
+
+ /*
+ * Likewise, bound things on the otherside by preventing insane quota
+ * periods. This also allows us to normalize in computing quota
+ * feasibility.
+ */
+ if (period > max_cfs_quota_period)
+ return -EINVAL;
+
+ mutex_lock(&cfs_constraints_mutex);
+ ret = __cfs_schedulable(tg, period, quota);
+ if (ret)
+ goto out_unlock;
+
+ runtime_enabled = quota != RUNTIME_INF;
+ raw_spin_lock_irq(&cfs_b->lock);
+ cfs_b->period = ns_to_ktime(period);
+ cfs_b->quota = quota;
+
+ __refill_cfs_bandwidth_runtime(cfs_b);
+ /* restart the period timer (if active) to handle new period expiry */
+ if (runtime_enabled && cfs_b->timer_active) {
+ /* force a reprogram */
+ cfs_b->timer_active = 0;
+ __start_cfs_bandwidth(cfs_b);
+ }
+ raw_spin_unlock_irq(&cfs_b->lock);
+
+ for_each_possible_cpu(i) {
+ struct cfs_rq *cfs_rq = tg->cfs_rq[i];
+ struct rq *rq = rq_of(cfs_rq);
+
+ raw_spin_lock_irq(&rq->lock);
+ cfs_rq->runtime_enabled = runtime_enabled;
+ cfs_rq->runtime_remaining = 0;
+
+ if (cfs_rq_throttled(cfs_rq))
+ unthrottle_cfs_rq(cfs_rq);
+ raw_spin_unlock_irq(&rq->lock);
+ }
+out_unlock:
+ mutex_unlock(&cfs_constraints_mutex);
+
+ return ret;
+}
+
+int tg_set_cfs_quota(struct task_group *tg, long cfs_quota_us)
+{
+ u64 quota, period;
+
+ period = ktime_to_ns(tg_cfs_bandwidth(tg)->period);
+ if (cfs_quota_us < 0)
+ quota = RUNTIME_INF;
+ else
+ quota = (u64)cfs_quota_us * NSEC_PER_USEC;
+
+ return tg_set_cfs_bandwidth(tg, period, quota);
+}
+
+long tg_get_cfs_quota(struct task_group *tg)
+{
+ u64 quota_us;
+
+ if (tg_cfs_bandwidth(tg)->quota == RUNTIME_INF)
+ return -1;
+
+ quota_us = tg_cfs_bandwidth(tg)->quota;
+ do_div(quota_us, NSEC_PER_USEC);
+
+ return quota_us;
+}
+
+int tg_set_cfs_period(struct task_group *tg, long cfs_period_us)
+{
+ u64 quota, period;
+
+ period = (u64)cfs_period_us * NSEC_PER_USEC;
+ quota = tg_cfs_bandwidth(tg)->quota;
+
+ if (period <= 0)
+ return -EINVAL;
+
+ return tg_set_cfs_bandwidth(tg, period, quota);
+}
+
+long tg_get_cfs_period(struct task_group *tg)
+{
+ u64 cfs_period_us;
+
+ cfs_period_us = ktime_to_ns(tg_cfs_bandwidth(tg)->period);
+ do_div(cfs_period_us, NSEC_PER_USEC);
+
+ return cfs_period_us;
+}
+
+static s64 cpu_cfs_quota_read_s64(struct cgroup *cgrp, struct cftype *cft)
+{
+ return tg_get_cfs_quota(cgroup_tg(cgrp));
+}
+
+static int cpu_cfs_quota_write_s64(struct cgroup *cgrp, struct cftype *cftype,
+ s64 cfs_quota_us)
+{
+ return tg_set_cfs_quota(cgroup_tg(cgrp), cfs_quota_us);
+}
+
+static u64 cpu_cfs_period_read_u64(struct cgroup *cgrp, struct cftype *cft)
+{
+ return tg_get_cfs_period(cgroup_tg(cgrp));
+}
+
+static int cpu_cfs_period_write_u64(struct cgroup *cgrp, struct cftype *cftype,
+ u64 cfs_period_us)
+{
+ return tg_set_cfs_period(cgroup_tg(cgrp), cfs_period_us);
+}
+
+struct cfs_schedulable_data {
+ struct task_group *tg;
+ u64 period, quota;
+};
+
+/*
+ * normalize group quota/period to be quota/max_period
+ * note: units are usecs
+ */
+static u64 normalize_cfs_quota(struct task_group *tg,
+ struct cfs_schedulable_data *d)
+{
+ u64 quota, period;
+
+ if (tg == d->tg) {
+ period = d->period;
+ quota = d->quota;
+ } else {
+ period = tg_get_cfs_period(tg);
+ quota = tg_get_cfs_quota(tg);
+ }
+
+ /* note: these should typically be equivalent */
+ if (quota == RUNTIME_INF || quota == -1)
+ return RUNTIME_INF;
+
+ return to_ratio(period, quota);
+}
+
+static int tg_cfs_schedulable_down(struct task_group *tg, void *data)
+{
+ struct cfs_schedulable_data *d = data;
+ struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(tg);
+ s64 quota = 0, parent_quota = -1;
+
+ if (!tg->parent) {
+ quota = RUNTIME_INF;
+ } else {
+ struct cfs_bandwidth *parent_b = tg_cfs_bandwidth(tg->parent);
+
+ quota = normalize_cfs_quota(tg, d);
+ parent_quota = parent_b->hierarchal_quota;
+
+ /*
+ * ensure max(child_quota) <= parent_quota, inherit when no
+ * limit is set
+ */
+ if (quota == RUNTIME_INF)
+ quota = parent_quota;
+ else if (parent_quota != RUNTIME_INF && quota > parent_quota)
+ return -EINVAL;
+ }
+ cfs_b->hierarchal_quota = quota;
+
+ return 0;
+}
+
+static int __cfs_schedulable(struct task_group *tg, u64 period, u64 quota)
+{
+ int ret;
+ struct cfs_schedulable_data data = {
+ .tg = tg,
+ .period = period,
+ .quota = quota,
+ };
+
+ if (quota != RUNTIME_INF) {
+ do_div(data.period, NSEC_PER_USEC);
+ do_div(data.quota, NSEC_PER_USEC);
+ }
+
+ rcu_read_lock();
+ ret = walk_tg_tree(tg_cfs_schedulable_down, tg_nop, &data);
+ rcu_read_unlock();
+
+ return ret;
+}
+
+static int cpu_stats_show(struct cgroup *cgrp, struct cftype *cft,
+ struct cgroup_map_cb *cb)
+{
+ struct task_group *tg = cgroup_tg(cgrp);
+ struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(tg);
+
+ cb->fill(cb, "nr_periods", cfs_b->nr_periods);
+ cb->fill(cb, "nr_throttled", cfs_b->nr_throttled);
+ cb->fill(cb, "throttled_time", cfs_b->throttled_time);
+
+ return 0;
+}
+#endif /* CONFIG_CFS_BANDWIDTH */
#endif /* CONFIG_FAIR_GROUP_SCHED */
#ifdef CONFIG_RT_GROUP_SCHED
@@ -9026,6 +9443,22 @@ static struct cftype cpu_files[] = {
.write_u64 = cpu_shares_write_u64,
},
#endif
+#ifdef CONFIG_CFS_BANDWIDTH
+ {
+ .name = "cfs_quota_us",
+ .read_s64 = cpu_cfs_quota_read_s64,
+ .write_s64 = cpu_cfs_quota_write_s64,
+ },
+ {
+ .name = "cfs_period_us",
+ .read_u64 = cpu_cfs_period_read_u64,
+ .write_u64 = cpu_cfs_period_write_u64,
+ },
+ {
+ .name = "stat",
+ .read_map = cpu_stats_show,
+ },
+#endif
#ifdef CONFIG_RT_GROUP_SCHED
{
.name = "rt_runtime_us",
@@ -9335,4 +9768,3 @@ struct cgroup_subsys cpuacct_subsys = {
.subsys_id = cpuacct_subsys_id,
};
#endif /* CONFIG_CGROUP_CPUACCT */
-