{
ktime_t now;
- if (rt_bandwidth_enabled() && rt_b->rt_runtime == RUNTIME_INF)
+ if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)
return;
if (hrtimer_active(&rt_b->rt_period_timer))
*/
static DEFINE_SPINLOCK(task_group_lock);
+#ifdef CONFIG_SMP
+static int root_task_group_empty(void)
+{
+ return list_empty(&root_task_group.children);
+}
+#endif
+
#ifdef CONFIG_FAIR_GROUP_SCHED
#ifdef CONFIG_USER_SCHED
# define INIT_TASK_GROUP_LOAD (2*NICE_0_LOAD)
#else
+#ifdef CONFIG_SMP
+static int root_task_group_empty(void)
+{
+ return 1;
+}
+#endif
+
static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { }
static inline struct task_group *task_group(struct task_struct *p)
{
struct rt_prio_array active;
unsigned long rt_nr_running;
#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
- int highest_prio; /* highest queued rt task prio */
+ struct {
+ int curr; /* highest queued rt task prio */
+#ifdef CONFIG_SMP
+ int next; /* next highest */
+#endif
+ } highest_prio;
#endif
#ifdef CONFIG_SMP
unsigned long rt_nr_migratory;
int overloaded;
+ struct plist_head pushable_tasks;
#endif
int rt_throttled;
u64 rt_time;
unsigned long nr_running;
#define CPU_LOAD_IDX_MAX 5
unsigned long cpu_load[CPU_LOAD_IDX_MAX];
- unsigned char idle_at_tick;
#ifdef CONFIG_NO_HZ
unsigned long last_tick_seen;
unsigned char in_nohz_recently;
struct root_domain *rd;
struct sched_domain *sd;
+ unsigned char idle_at_tick;
/* For active balancing */
int active_balance;
int push_cpu;
/* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
/* sys_sched_yield() stats */
- unsigned int yld_exp_empty;
- unsigned int yld_act_empty;
- unsigned int yld_both_empty;
unsigned int yld_count;
/* schedule() stats */
assert_spin_locked(&task_rq(p)->lock);
- if (unlikely(test_tsk_thread_flag(p, TIF_NEED_RESCHED)))
+ if (test_tsk_need_resched(p))
return;
- set_tsk_thread_flag(p, TIF_NEED_RESCHED);
+ set_tsk_need_resched(p);
cpu = task_cpu(p);
if (cpu == smp_processor_id())
* lockless. The worst case is that the other CPU runs the
* idle task through an additional NOOP schedule()
*/
- set_tsk_thread_flag(rq->idle, TIF_NEED_RESCHED);
+ set_tsk_need_resched(rq->idle);
/* NEED_RESCHED must be visible before we test polling */
smp_mb();
#endif
+#ifdef CONFIG_PREEMPT
+
/*
- * double_lock_balance - lock the busiest runqueue, this_rq is locked already.
+ * fair double_lock_balance: Safely acquires both rq->locks in a fair
+ * way at the expense of forcing extra atomic operations in all
+ * invocations. This assures that the double_lock is acquired using the
+ * same underlying policy as the spinlock_t on this architecture, which
+ * reduces latency compared to the unfair variant below. However, it
+ * also adds more overhead and therefore may reduce throughput.
*/
-static int double_lock_balance(struct rq *this_rq, struct rq *busiest)
+static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
+ __releases(this_rq->lock)
+ __acquires(busiest->lock)
+ __acquires(this_rq->lock)
+{
+ spin_unlock(&this_rq->lock);
+ double_rq_lock(this_rq, busiest);
+
+ return 1;
+}
+
+#else
+/*
+ * Unfair double_lock_balance: Optimizes throughput at the expense of
+ * latency by eliminating extra atomic operations when the locks are
+ * already in proper order on entry. This favors lower cpu-ids and will
+ * grant the double lock to lower cpus over higher ids under contention,
+ * regardless of entry order into the function.
+ */
+static int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
__releases(this_rq->lock)
__acquires(busiest->lock)
__acquires(this_rq->lock)
{
int ret = 0;
- if (unlikely(!irqs_disabled())) {
- /* printk() doesn't work good under rq->lock */
- spin_unlock(&this_rq->lock);
- BUG_ON(1);
- }
if (unlikely(!spin_trylock(&busiest->lock))) {
if (busiest < this_rq) {
spin_unlock(&this_rq->lock);
return ret;
}
+#endif /* CONFIG_PREEMPT */
+
+/*
+ * double_lock_balance - lock the busiest runqueue, this_rq is locked already.
+ */
+static int double_lock_balance(struct rq *this_rq, struct rq *busiest)
+{
+ if (unlikely(!irqs_disabled())) {
+ /* printk() doesn't work good under rq->lock */
+ spin_unlock(&this_rq->lock);
+ BUG_ON(1);
+ }
+
+ return _double_lock_balance(this_rq, busiest);
+}
+
static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest)
__releases(busiest->lock)
{
static void enqueue_task(struct rq *rq, struct task_struct *p, int wakeup)
{
+ if (wakeup)
+ p->se.start_runtime = p->se.sum_exec_runtime;
+
sched_info_queued(p);
p->sched_class->enqueue_task(rq, p, wakeup);
p->se.on_rq = 1;
static void dequeue_task(struct rq *rq, struct task_struct *p, int sleep)
{
- if (sleep && p->se.last_wakeup) {
- update_avg(&p->se.avg_overlap,
- p->se.sum_exec_runtime - p->se.last_wakeup);
- p->se.last_wakeup = 0;
+ if (sleep) {
+ if (p->se.last_wakeup) {
+ update_avg(&p->se.avg_overlap,
+ p->se.sum_exec_runtime - p->se.last_wakeup);
+ p->se.last_wakeup = 0;
+ } else {
+ update_avg(&p->se.avg_wakeup,
+ sysctl_sched_wakeup_granularity);
+ }
}
sched_info_dequeued(p);
* it must be off the runqueue _entirely_, and not
* preempted!
*
- * So if it wa still runnable (but just not actively
+ * So if it was still runnable (but just not actively
* running right now), it's preempted, and we should
* yield - it could be a while.
*/
if (!sched_feat(SYNC_WAKEUPS))
sync = 0;
- if (!sync) {
- if (current->se.avg_overlap < sysctl_sched_migration_cost &&
- p->se.avg_overlap < sysctl_sched_migration_cost)
- sync = 1;
- } else {
- if (current->se.avg_overlap >= sysctl_sched_migration_cost ||
- p->se.avg_overlap >= sysctl_sched_migration_cost)
- sync = 0;
- }
-
#ifdef CONFIG_SMP
- if (sched_feat(LB_WAKEUP_UPDATE)) {
+ if (sched_feat(LB_WAKEUP_UPDATE) && !root_task_group_empty()) {
struct sched_domain *sd;
this_cpu = raw_smp_processor_id();
activate_task(rq, p, 1);
success = 1;
+ /*
+ * Only attribute actual wakeups done by this task.
+ */
+ if (!in_interrupt()) {
+ struct sched_entity *se = ¤t->se;
+ u64 sample = se->sum_exec_runtime;
+
+ if (se->last_wakeup)
+ sample -= se->last_wakeup;
+ else
+ sample -= se->start_runtime;
+ update_avg(&se->avg_wakeup, sample);
+
+ se->last_wakeup = se->sum_exec_runtime;
+ }
+
out_running:
trace_sched_wakeup(rq, p, success);
check_preempt_curr(rq, p, sync);
p->sched_class->task_wake_up(rq, p);
#endif
out:
- current->se.last_wakeup = current->se.sum_exec_runtime;
-
task_rq_unlock(rq, &flags);
return success;
p->se.prev_sum_exec_runtime = 0;
p->se.last_wakeup = 0;
p->se.avg_overlap = 0;
+ p->se.start_runtime = 0;
+ p->se.avg_wakeup = sysctl_sched_wakeup_granularity;
#ifdef CONFIG_SCHEDSTATS
p->se.wait_start = 0;
/* Want to start with kernel preemption disabled. */
task_thread_info(p)->preempt_count = 1;
#endif
+ plist_node_init(&p->pushable_tasks, MAX_PRIO);
+
put_cpu();
}
#ifdef CONFIG_PREEMPT_NOTIFIERS
/**
- * preempt_notifier_register - tell me when current is being being preempted & rescheduled
+ * preempt_notifier_register - tell me when current is being preempted & rescheduled
* @notifier: notifier struct to register
*/
void preempt_notifier_register(struct preempt_notifier *notifier)
{
struct mm_struct *mm = rq->prev_mm;
long prev_state;
+#ifdef CONFIG_SMP
+ int post_schedule = 0;
+
+ if (current->sched_class->needs_post_schedule)
+ post_schedule = current->sched_class->needs_post_schedule(rq);
+#endif
rq->prev_mm = NULL;
finish_arch_switch(prev);
finish_lock_switch(rq, prev);
#ifdef CONFIG_SMP
- if (current->sched_class->post_schedule)
+ if (post_schedule)
current->sched_class->post_schedule(rq);
#endif
struct sched_domain *sd, enum cpu_idle_type idle,
int *all_pinned)
{
+ int tsk_cache_hot = 0;
/*
* We do not migrate tasks that are:
* 1) running (obviously), or
* 2) too many balance attempts have failed.
*/
- if (!task_hot(p, rq->clock, sd) ||
- sd->nr_balance_failed > sd->cache_nice_tries) {
+ tsk_cache_hot = task_hot(p, rq->clock, sd);
+ if (!tsk_cache_hot ||
+ sd->nr_balance_failed > sd->cache_nice_tries) {
#ifdef CONFIG_SCHEDSTATS
- if (task_hot(p, rq->clock, sd)) {
+ if (tsk_cache_hot) {
schedstat_inc(sd, lb_hot_gained[idle]);
schedstat_inc(p, se.nr_forced_migrations);
}
return 1;
}
- if (task_hot(p, rq->clock, sd)) {
+ if (tsk_cache_hot) {
schedstat_inc(p, se.nr_failed_migrations_hot);
return 0;
}
pulled++;
rem_load_move -= p->se.load.weight;
+#ifdef CONFIG_PREEMPT
+ /*
+ * NEWIDLE balancing is a source of latency, so preemptible kernels
+ * will stop after the first task is pulled to minimize the critical
+ * section.
+ */
+ if (idle == CPU_NEWLY_IDLE)
+ goto out;
+#endif
+
/*
* We only want to steal up to the prescribed amount of weighted load.
*/
sd, idle, all_pinned, &this_best_prio);
class = class->next;
+#ifdef CONFIG_PREEMPT
+ /*
+ * NEWIDLE balancing is a source of latency, so preemptible
+ * kernels will stop after the first task is pulled to minimize
+ * the critical section.
+ */
if (idle == CPU_NEWLY_IDLE && this_rq->nr_running)
break;
-
+#endif
} while (class && max_load_move > total_load_moved);
return total_load_moved > 0;
return 0;
}
-
+/********** Helpers for find_busiest_group ************************/
/*
- * find_busiest_group finds and returns the busiest CPU group within the
- * domain. It calculates and returns the amount of weighted load which
- * should be moved to restore balance via the imbalance parameter.
+ * sd_lb_stats - Structure to store the statistics of a sched_domain
+ * during load balancing.
*/
-static struct sched_group *
-find_busiest_group(struct sched_domain *sd, int this_cpu,
- unsigned long *imbalance, enum cpu_idle_type idle,
- int *sd_idle, const struct cpumask *cpus, int *balance)
-{
- struct sched_group *busiest = NULL, *this = NULL, *group = sd->groups;
- unsigned long max_load, avg_load, total_load, this_load, total_pwr;
- unsigned long max_pull;
- unsigned long busiest_load_per_task, busiest_nr_running;
- unsigned long this_load_per_task, this_nr_running;
- int load_idx, group_imb = 0;
+struct sd_lb_stats {
+ struct sched_group *busiest; /* Busiest group in this sd */
+ struct sched_group *this; /* Local group in this sd */
+ unsigned long total_load; /* Total load of all groups in sd */
+ unsigned long total_pwr; /* Total power of all groups in sd */
+ unsigned long avg_load; /* Average load across all groups in sd */
+
+ /** Statistics of this group */
+ unsigned long this_load;
+ unsigned long this_load_per_task;
+ unsigned long this_nr_running;
+
+ /* Statistics of the busiest group */
+ unsigned long max_load;
+ unsigned long busiest_load_per_task;
+ unsigned long busiest_nr_running;
+
+ int group_imb; /* Is there imbalance in this sd */
#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
- int power_savings_balance = 1;
- unsigned long leader_nr_running = 0, min_load_per_task = 0;
- unsigned long min_nr_running = ULONG_MAX;
- struct sched_group *group_min = NULL, *group_leader = NULL;
+ int power_savings_balance; /* Is powersave balance needed for this sd */
+ struct sched_group *group_min; /* Least loaded group in sd */
+ struct sched_group *group_leader; /* Group which relieves group_min */
+ unsigned long min_load_per_task; /* load_per_task in group_min */
+ unsigned long leader_nr_running; /* Nr running of group_leader */
+ unsigned long min_nr_running; /* Nr running of group_min */
#endif
+};
+
+/*
+ * sg_lb_stats - stats of a sched_group required for load_balancing
+ */
+struct sg_lb_stats {
+ unsigned long avg_load; /*Avg load across the CPUs of the group */
+ unsigned long group_load; /* Total load over the CPUs of the group */
+ unsigned long sum_nr_running; /* Nr tasks running in the group */
+ unsigned long sum_weighted_load; /* Weighted load of group's tasks */
+ unsigned long group_capacity;
+ int group_imb; /* Is there an imbalance in the group ? */
+};
- max_load = this_load = total_load = total_pwr = 0;
- busiest_load_per_task = busiest_nr_running = 0;
- this_load_per_task = this_nr_running = 0;
+/**
+ * group_first_cpu - Returns the first cpu in the cpumask of a sched_group.
+ * @group: The group whose first cpu is to be returned.
+ */
+static inline unsigned int group_first_cpu(struct sched_group *group)
+{
+ return cpumask_first(sched_group_cpus(group));
+}
- if (idle == CPU_NOT_IDLE)
+/**
+ * get_sd_load_idx - Obtain the load index for a given sched domain.
+ * @sd: The sched_domain whose load_idx is to be obtained.
+ * @idle: The Idle status of the CPU for whose sd load_icx is obtained.
+ */
+static inline int get_sd_load_idx(struct sched_domain *sd,
+ enum cpu_idle_type idle)
+{
+ int load_idx;
+
+ switch (idle) {
+ case CPU_NOT_IDLE:
load_idx = sd->busy_idx;
- else if (idle == CPU_NEWLY_IDLE)
+ break;
+
+ case CPU_NEWLY_IDLE:
load_idx = sd->newidle_idx;
- else
+ break;
+ default:
load_idx = sd->idle_idx;
+ break;
+ }
- do {
- unsigned long load, group_capacity, max_cpu_load, min_cpu_load;
- int local_group;
- int i;
- int __group_imb = 0;
- unsigned int balance_cpu = -1, first_idle_cpu = 0;
- unsigned long sum_nr_running, sum_weighted_load;
- unsigned long sum_avg_load_per_task;
- unsigned long avg_load_per_task;
+ return load_idx;
+}
- local_group = cpumask_test_cpu(this_cpu,
- sched_group_cpus(group));
- if (local_group)
- balance_cpu = cpumask_first(sched_group_cpus(group));
+#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
+/**
+ * init_sd_power_savings_stats - Initialize power savings statistics for
+ * the given sched_domain, during load balancing.
+ *
+ * @sd: Sched domain whose power-savings statistics are to be initialized.
+ * @sds: Variable containing the statistics for sd.
+ * @idle: Idle status of the CPU at which we're performing load-balancing.
+ */
+static inline void init_sd_power_savings_stats(struct sched_domain *sd,
+ struct sd_lb_stats *sds, enum cpu_idle_type idle)
+{
+ /*
+ * Busy processors will not participate in power savings
+ * balance.
+ */
+ if (idle == CPU_NOT_IDLE || !(sd->flags & SD_POWERSAVINGS_BALANCE))
+ sds->power_savings_balance = 0;
+ else {
+ sds->power_savings_balance = 1;
+ sds->min_nr_running = ULONG_MAX;
+ sds->leader_nr_running = 0;
+ }
+}
+
+/**
+ * update_sd_power_savings_stats - Update the power saving stats for a
+ * sched_domain while performing load balancing.
+ *
+ * @group: sched_group belonging to the sched_domain under consideration.
+ * @sds: Variable containing the statistics of the sched_domain
+ * @local_group: Does group contain the CPU for which we're performing
+ * load balancing ?
+ * @sgs: Variable containing the statistics of the group.
+ */
+static inline void update_sd_power_savings_stats(struct sched_group *group,
+ struct sd_lb_stats *sds, int local_group, struct sg_lb_stats *sgs)
+{
- /* Tally up the load of all CPUs in the group */
- sum_weighted_load = sum_nr_running = avg_load = 0;
- sum_avg_load_per_task = avg_load_per_task = 0;
+ if (!sds->power_savings_balance)
+ return;
- max_cpu_load = 0;
- min_cpu_load = ~0UL;
+ /*
+ * If the local group is idle or completely loaded
+ * no need to do power savings balance at this domain
+ */
+ if (local_group && (sds->this_nr_running >= sgs->group_capacity ||
+ !sds->this_nr_running))
+ sds->power_savings_balance = 0;
- for_each_cpu_and(i, sched_group_cpus(group), cpus) {
- struct rq *rq = cpu_rq(i);
+ /*
+ * If a group is already running at full capacity or idle,
+ * don't include that group in power savings calculations
+ */
+ if (!sds->power_savings_balance ||
+ sgs->sum_nr_running >= sgs->group_capacity ||
+ !sgs->sum_nr_running)
+ return;
- if (*sd_idle && rq->nr_running)
- *sd_idle = 0;
+ /*
+ * Calculate the group which has the least non-idle load.
+ * This is the group from where we need to pick up the load
+ * for saving power
+ */
+ if ((sgs->sum_nr_running < sds->min_nr_running) ||
+ (sgs->sum_nr_running == sds->min_nr_running &&
+ group_first_cpu(group) > group_first_cpu(sds->group_min))) {
+ sds->group_min = group;
+ sds->min_nr_running = sgs->sum_nr_running;
+ sds->min_load_per_task = sgs->sum_weighted_load /
+ sgs->sum_nr_running;
+ }
- /* Bias balancing toward cpus of our domain */
- if (local_group) {
- if (idle_cpu(i) && !first_idle_cpu) {
- first_idle_cpu = 1;
- balance_cpu = i;
- }
+ /*
+ * Calculate the group which is almost near its
+ * capacity but still has some space to pick up some load
+ * from other group and save more power
+ */
+ if (sgs->sum_nr_running > sgs->group_capacity - 1)
+ return;
- load = target_load(i, load_idx);
- } else {
- load = source_load(i, load_idx);
- if (load > max_cpu_load)
- max_cpu_load = load;
- if (min_cpu_load > load)
- min_cpu_load = load;
- }
+ if (sgs->sum_nr_running > sds->leader_nr_running ||
+ (sgs->sum_nr_running == sds->leader_nr_running &&
+ group_first_cpu(group) < group_first_cpu(sds->group_leader))) {
+ sds->group_leader = group;
+ sds->leader_nr_running = sgs->sum_nr_running;
+ }
+}
- avg_load += load;
- sum_nr_running += rq->nr_running;
- sum_weighted_load += weighted_cpuload(i);
+/**
+ * check_power_save_busiest_group - see if there is potential for some power-savings balance
+ * @sds: Variable containing the statistics of the sched_domain
+ * under consideration.
+ * @this_cpu: Cpu at which we're currently performing load-balancing.
+ * @imbalance: Variable to store the imbalance.
+ *
+ * Description:
+ * Check if we have potential to perform some power-savings balance.
+ * If yes, set the busiest group to be the least loaded group in the
+ * sched_domain, so that it's CPUs can be put to idle.
+ *
+ * Returns 1 if there is potential to perform power-savings balance.
+ * Else returns 0.
+ */
+static inline int check_power_save_busiest_group(struct sd_lb_stats *sds,
+ int this_cpu, unsigned long *imbalance)
+{
+ if (!sds->power_savings_balance)
+ return 0;
- sum_avg_load_per_task += cpu_avg_load_per_task(i);
- }
+ if (sds->this != sds->group_leader ||
+ sds->group_leader == sds->group_min)
+ return 0;
- /*
- * First idle cpu or the first cpu(busiest) in this sched group
- * is eligible for doing load balancing at this and above
- * domains. In the newly idle case, we will allow all the cpu's
- * to do the newly idle load balance.
- */
- if (idle != CPU_NEWLY_IDLE && local_group &&
- balance_cpu != this_cpu && balance) {
- *balance = 0;
- goto ret;
- }
+ *imbalance = sds->min_load_per_task;
+ sds->busiest = sds->group_min;
- total_load += avg_load;
- total_pwr += group->__cpu_power;
+ if (sched_mc_power_savings >= POWERSAVINGS_BALANCE_WAKEUP) {
+ cpu_rq(this_cpu)->rd->sched_mc_preferred_wakeup_cpu =
+ group_first_cpu(sds->group_leader);
+ }
- /* Adjust by relative CPU power of the group */
- avg_load = sg_div_cpu_power(group,
- avg_load * SCHED_LOAD_SCALE);
+ return 1;
+}
+#else /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */
+static inline void init_sd_power_savings_stats(struct sched_domain *sd,
+ struct sd_lb_stats *sds, enum cpu_idle_type idle)
+{
+ return;
+}
- /*
- * Consider the group unbalanced when the imbalance is larger
- * than the average weight of two tasks.
- *
- * APZ: with cgroup the avg task weight can vary wildly and
- * might not be a suitable number - should we keep a
- * normalized nr_running number somewhere that negates
- * the hierarchy?
- */
- avg_load_per_task = sg_div_cpu_power(group,
- sum_avg_load_per_task * SCHED_LOAD_SCALE);
+static inline void update_sd_power_savings_stats(struct sched_group *group,
+ struct sd_lb_stats *sds, int local_group, struct sg_lb_stats *sgs)
+{
+ return;
+}
- if ((max_cpu_load - min_cpu_load) > 2*avg_load_per_task)
- __group_imb = 1;
+static inline int check_power_save_busiest_group(struct sd_lb_stats *sds,
+ int this_cpu, unsigned long *imbalance)
+{
+ return 0;
+}
+#endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */
- group_capacity = group->__cpu_power / SCHED_LOAD_SCALE;
+/**
+ * update_sg_lb_stats - Update sched_group's statistics for load balancing.
+ * @group: sched_group whose statistics are to be updated.
+ * @this_cpu: Cpu for which load balance is currently performed.
+ * @idle: Idle status of this_cpu
+ * @load_idx: Load index of sched_domain of this_cpu for load calc.
+ * @sd_idle: Idle status of the sched_domain containing group.
+ * @local_group: Does group contain this_cpu.
+ * @cpus: Set of cpus considered for load balancing.
+ * @balance: Should we balance.
+ * @sgs: variable to hold the statistics for this group.
+ */
+static inline void update_sg_lb_stats(struct sched_group *group, int this_cpu,
+ enum cpu_idle_type idle, int load_idx, int *sd_idle,
+ int local_group, const struct cpumask *cpus,
+ int *balance, struct sg_lb_stats *sgs)
+{
+ unsigned long load, max_cpu_load, min_cpu_load;
+ int i;
+ unsigned int balance_cpu = -1, first_idle_cpu = 0;
+ unsigned long sum_avg_load_per_task;
+ unsigned long avg_load_per_task;
+
+ if (local_group)
+ balance_cpu = group_first_cpu(group);
+
+ /* Tally up the load of all CPUs in the group */
+ sum_avg_load_per_task = avg_load_per_task = 0;
+ max_cpu_load = 0;
+ min_cpu_load = ~0UL;
+
+ for_each_cpu_and(i, sched_group_cpus(group), cpus) {
+ struct rq *rq = cpu_rq(i);
+
+ if (*sd_idle && rq->nr_running)
+ *sd_idle = 0;
+
+ /* Bias balancing toward cpus of our domain */
if (local_group) {
- this_load = avg_load;
- this = group;
- this_nr_running = sum_nr_running;
- this_load_per_task = sum_weighted_load;
- } else if (avg_load > max_load &&
- (sum_nr_running > group_capacity || __group_imb)) {
- max_load = avg_load;
- busiest = group;
- busiest_nr_running = sum_nr_running;
- busiest_load_per_task = sum_weighted_load;
- group_imb = __group_imb;
+ if (idle_cpu(i) && !first_idle_cpu) {
+ first_idle_cpu = 1;
+ balance_cpu = i;
+ }
+
+ load = target_load(i, load_idx);
+ } else {
+ load = source_load(i, load_idx);
+ if (load > max_cpu_load)
+ max_cpu_load = load;
+ if (min_cpu_load > load)
+ min_cpu_load = load;
}
-#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
- /*
- * Busy processors will not participate in power savings
- * balance.
- */
- if (idle == CPU_NOT_IDLE ||
- !(sd->flags & SD_POWERSAVINGS_BALANCE))
- goto group_next;
+ sgs->group_load += load;
+ sgs->sum_nr_running += rq->nr_running;
+ sgs->sum_weighted_load += weighted_cpuload(i);
- /*
- * If the local group is idle or completely loaded
- * no need to do power savings balance at this domain
- */
- if (local_group && (this_nr_running >= group_capacity ||
- !this_nr_running))
- power_savings_balance = 0;
+ sum_avg_load_per_task += cpu_avg_load_per_task(i);
+ }
- /*
- * If a group is already running at full capacity or idle,
- * don't include that group in power savings calculations
- */
- if (!power_savings_balance || sum_nr_running >= group_capacity
- || !sum_nr_running)
- goto group_next;
+ /*
+ * First idle cpu or the first cpu(busiest) in this sched group
+ * is eligible for doing load balancing at this and above
+ * domains. In the newly idle case, we will allow all the cpu's
+ * to do the newly idle load balance.
+ */
+ if (idle != CPU_NEWLY_IDLE && local_group &&
+ balance_cpu != this_cpu && balance) {
+ *balance = 0;
+ return;
+ }
- /*
- * Calculate the group which has the least non-idle load.
- * This is the group from where we need to pick up the load
- * for saving power
- */
- if ((sum_nr_running < min_nr_running) ||
- (sum_nr_running == min_nr_running &&
- cpumask_first(sched_group_cpus(group)) >
- cpumask_first(sched_group_cpus(group_min)))) {
- group_min = group;
- min_nr_running = sum_nr_running;
- min_load_per_task = sum_weighted_load /
- sum_nr_running;
- }
+ /* Adjust by relative CPU power of the group */
+ sgs->avg_load = sg_div_cpu_power(group,
+ sgs->group_load * SCHED_LOAD_SCALE);
- /*
- * Calculate the group which is almost near its
- * capacity but still has some space to pick up some load
- * from other group and save more power
- */
- if (sum_nr_running <= group_capacity - 1) {
- if (sum_nr_running > leader_nr_running ||
- (sum_nr_running == leader_nr_running &&
- cpumask_first(sched_group_cpus(group)) <
- cpumask_first(sched_group_cpus(group_leader)))) {
- group_leader = group;
- leader_nr_running = sum_nr_running;
- }
+
+ /*
+ * Consider the group unbalanced when the imbalance is larger
+ * than the average weight of two tasks.
+ *
+ * APZ: with cgroup the avg task weight can vary wildly and
+ * might not be a suitable number - should we keep a
+ * normalized nr_running number somewhere that negates
+ * the hierarchy?
+ */
+ avg_load_per_task = sg_div_cpu_power(group,
+ sum_avg_load_per_task * SCHED_LOAD_SCALE);
+
+ if ((max_cpu_load - min_cpu_load) > 2*avg_load_per_task)
+ sgs->group_imb = 1;
+
+ sgs->group_capacity = group->__cpu_power / SCHED_LOAD_SCALE;
+
+}
+
+/**
+ * update_sd_lb_stats - Update sched_group's statistics for load balancing.
+ * @sd: sched_domain whose statistics are to be updated.
+ * @this_cpu: Cpu for which load balance is currently performed.
+ * @idle: Idle status of this_cpu
+ * @sd_idle: Idle status of the sched_domain containing group.
+ * @cpus: Set of cpus considered for load balancing.
+ * @balance: Should we balance.
+ * @sds: variable to hold the statistics for this sched_domain.
+ */
+static inline void update_sd_lb_stats(struct sched_domain *sd, int this_cpu,
+ enum cpu_idle_type idle, int *sd_idle,
+ const struct cpumask *cpus, int *balance,
+ struct sd_lb_stats *sds)
+{
+ struct sched_group *group = sd->groups;
+ struct sg_lb_stats sgs;
+ int load_idx;
+
+ init_sd_power_savings_stats(sd, sds, idle);
+ load_idx = get_sd_load_idx(sd, idle);
+
+ do {
+ int local_group;
+
+ local_group = cpumask_test_cpu(this_cpu,
+ sched_group_cpus(group));
+ memset(&sgs, 0, sizeof(sgs));
+ update_sg_lb_stats(group, this_cpu, idle, load_idx, sd_idle,
+ local_group, cpus, balance, &sgs);
+
+ if (local_group && balance && !(*balance))
+ return;
+
+ sds->total_load += sgs.group_load;
+ sds->total_pwr += group->__cpu_power;
+
+ if (local_group) {
+ sds->this_load = sgs.avg_load;
+ sds->this = group;
+ sds->this_nr_running = sgs.sum_nr_running;
+ sds->this_load_per_task = sgs.sum_weighted_load;
+ } else if (sgs.avg_load > sds->max_load &&
+ (sgs.sum_nr_running > sgs.group_capacity ||
+ sgs.group_imb)) {
+ sds->max_load = sgs.avg_load;
+ sds->busiest = group;
+ sds->busiest_nr_running = sgs.sum_nr_running;
+ sds->busiest_load_per_task = sgs.sum_weighted_load;
+ sds->group_imb = sgs.group_imb;
}
-group_next:
-#endif
+
+ update_sd_power_savings_stats(group, sds, local_group, &sgs);
group = group->next;
} while (group != sd->groups);
- if (!busiest || this_load >= max_load || busiest_nr_running == 0)
- goto out_balanced;
-
- avg_load = (SCHED_LOAD_SCALE * total_load) / total_pwr;
+}
- if (this_load >= avg_load ||
- 100*max_load <= sd->imbalance_pct*this_load)
- goto out_balanced;
+/**
+ * fix_small_imbalance - Calculate the minor imbalance that exists
+ * amongst the groups of a sched_domain, during
+ * load balancing.
+ * @sds: Statistics of the sched_domain whose imbalance is to be calculated.
+ * @this_cpu: The cpu at whose sched_domain we're performing load-balance.
+ * @imbalance: Variable to store the imbalance.
+ */
+static inline void fix_small_imbalance(struct sd_lb_stats *sds,
+ int this_cpu, unsigned long *imbalance)
+{
+ unsigned long tmp, pwr_now = 0, pwr_move = 0;
+ unsigned int imbn = 2;
+
+ if (sds->this_nr_running) {
+ sds->this_load_per_task /= sds->this_nr_running;
+ if (sds->busiest_load_per_task >
+ sds->this_load_per_task)
+ imbn = 1;
+ } else
+ sds->this_load_per_task =
+ cpu_avg_load_per_task(this_cpu);
- busiest_load_per_task /= busiest_nr_running;
- if (group_imb)
- busiest_load_per_task = min(busiest_load_per_task, avg_load);
+ if (sds->max_load - sds->this_load + sds->busiest_load_per_task >=
+ sds->busiest_load_per_task * imbn) {
+ *imbalance = sds->busiest_load_per_task;
+ return;
+ }
/*
- * We're trying to get all the cpus to the average_load, so we don't
- * want to push ourselves above the average load, nor do we wish to
- * reduce the max loaded cpu below the average load, as either of these
- * actions would just result in more rebalancing later, and ping-pong
- * tasks around. Thus we look for the minimum possible imbalance.
- * Negative imbalances (*we* are more loaded than anyone else) will
- * be counted as no imbalance for these purposes -- we can't fix that
- * by pulling tasks to us. Be careful of negative numbers as they'll
- * appear as very large values with unsigned longs.
+ * OK, we don't have enough imbalance to justify moving tasks,
+ * however we may be able to increase total CPU power used by
+ * moving them.
*/
- if (max_load <= busiest_load_per_task)
- goto out_balanced;
+ pwr_now += sds->busiest->__cpu_power *
+ min(sds->busiest_load_per_task, sds->max_load);
+ pwr_now += sds->this->__cpu_power *
+ min(sds->this_load_per_task, sds->this_load);
+ pwr_now /= SCHED_LOAD_SCALE;
+
+ /* Amount of load we'd subtract */
+ tmp = sg_div_cpu_power(sds->busiest,
+ sds->busiest_load_per_task * SCHED_LOAD_SCALE);
+ if (sds->max_load > tmp)
+ pwr_move += sds->busiest->__cpu_power *
+ min(sds->busiest_load_per_task, sds->max_load - tmp);
+
+ /* Amount of load we'd add */
+ if (sds->max_load * sds->busiest->__cpu_power <
+ sds->busiest_load_per_task * SCHED_LOAD_SCALE)
+ tmp = sg_div_cpu_power(sds->this,
+ sds->max_load * sds->busiest->__cpu_power);
+ else
+ tmp = sg_div_cpu_power(sds->this,
+ sds->busiest_load_per_task * SCHED_LOAD_SCALE);
+ pwr_move += sds->this->__cpu_power *
+ min(sds->this_load_per_task, sds->this_load + tmp);
+ pwr_move /= SCHED_LOAD_SCALE;
+
+ /* Move if we gain throughput */
+ if (pwr_move > pwr_now)
+ *imbalance = sds->busiest_load_per_task;
+}
+
+/**
+ * calculate_imbalance - Calculate the amount of imbalance present within the
+ * groups of a given sched_domain during load balance.
+ * @sds: statistics of the sched_domain whose imbalance is to be calculated.
+ * @this_cpu: Cpu for which currently load balance is being performed.
+ * @imbalance: The variable to store the imbalance.
+ */
+static inline void calculate_imbalance(struct sd_lb_stats *sds, int this_cpu,
+ unsigned long *imbalance)
+{
+ unsigned long max_pull;
/*
* In the presence of smp nice balancing, certain scenarios can have
* max load less than avg load(as we skip the groups at or below
* its cpu_power, while calculating max_load..)
*/
- if (max_load < avg_load) {
+ if (sds->max_load < sds->avg_load) {
*imbalance = 0;
- goto small_imbalance;
+ return fix_small_imbalance(sds, this_cpu, imbalance);
}
/* Don't want to pull so many tasks that a group would go idle */
- max_pull = min(max_load - avg_load, max_load - busiest_load_per_task);
+ max_pull = min(sds->max_load - sds->avg_load,
+ sds->max_load - sds->busiest_load_per_task);
/* How much load to actually move to equalise the imbalance */
- *imbalance = min(max_pull * busiest->__cpu_power,
- (avg_load - this_load) * this->__cpu_power)
+ *imbalance = min(max_pull * sds->busiest->__cpu_power,
+ (sds->avg_load - sds->this_load) * sds->this->__cpu_power)
/ SCHED_LOAD_SCALE;
/*
* a think about bumping its value to force at least one task to be
* moved
*/
- if (*imbalance < busiest_load_per_task) {
- unsigned long tmp, pwr_now, pwr_move;
- unsigned int imbn;
-
-small_imbalance:
- pwr_move = pwr_now = 0;
- imbn = 2;
- if (this_nr_running) {
- this_load_per_task /= this_nr_running;
- if (busiest_load_per_task > this_load_per_task)
- imbn = 1;
- } else
- this_load_per_task = cpu_avg_load_per_task(this_cpu);
+ if (*imbalance < sds->busiest_load_per_task)
+ return fix_small_imbalance(sds, this_cpu, imbalance);
- if (max_load - this_load + busiest_load_per_task >=
- busiest_load_per_task * imbn) {
- *imbalance = busiest_load_per_task;
- return busiest;
- }
+}
+/******* find_busiest_group() helpers end here *********************/
- /*
- * OK, we don't have enough imbalance to justify moving tasks,
- * however we may be able to increase total CPU power used by
- * moving them.
- */
+/**
+ * find_busiest_group - Returns the busiest group within the sched_domain
+ * if there is an imbalance. If there isn't an imbalance, and
+ * the user has opted for power-savings, it returns a group whose
+ * CPUs can be put to idle by rebalancing those tasks elsewhere, if
+ * such a group exists.
+ *
+ * Also calculates the amount of weighted load which should be moved
+ * to restore balance.
+ *
+ * @sd: The sched_domain whose busiest group is to be returned.
+ * @this_cpu: The cpu for which load balancing is currently being performed.
+ * @imbalance: Variable which stores amount of weighted load which should
+ * be moved to restore balance/put a group to idle.
+ * @idle: The idle status of this_cpu.
+ * @sd_idle: The idleness of sd
+ * @cpus: The set of CPUs under consideration for load-balancing.
+ * @balance: Pointer to a variable indicating if this_cpu
+ * is the appropriate cpu to perform load balancing at this_level.
+ *
+ * Returns: - the busiest group if imbalance exists.
+ * - If no imbalance and user has opted for power-savings balance,
+ * return the least loaded group whose CPUs can be
+ * put to idle by rebalancing its tasks onto our group.
+ */
+static struct sched_group *
+find_busiest_group(struct sched_domain *sd, int this_cpu,
+ unsigned long *imbalance, enum cpu_idle_type idle,
+ int *sd_idle, const struct cpumask *cpus, int *balance)
+{
+ struct sd_lb_stats sds;
- pwr_now += busiest->__cpu_power *
- min(busiest_load_per_task, max_load);
- pwr_now += this->__cpu_power *
- min(this_load_per_task, this_load);
- pwr_now /= SCHED_LOAD_SCALE;
-
- /* Amount of load we'd subtract */
- tmp = sg_div_cpu_power(busiest,
- busiest_load_per_task * SCHED_LOAD_SCALE);
- if (max_load > tmp)
- pwr_move += busiest->__cpu_power *
- min(busiest_load_per_task, max_load - tmp);
-
- /* Amount of load we'd add */
- if (max_load * busiest->__cpu_power <
- busiest_load_per_task * SCHED_LOAD_SCALE)
- tmp = sg_div_cpu_power(this,
- max_load * busiest->__cpu_power);
- else
- tmp = sg_div_cpu_power(this,
- busiest_load_per_task * SCHED_LOAD_SCALE);
- pwr_move += this->__cpu_power *
- min(this_load_per_task, this_load + tmp);
- pwr_move /= SCHED_LOAD_SCALE;
+ memset(&sds, 0, sizeof(sds));
- /* Move if we gain throughput */
- if (pwr_move > pwr_now)
- *imbalance = busiest_load_per_task;
- }
+ /*
+ * Compute the various statistics relavent for load balancing at
+ * this level.
+ */
+ update_sd_lb_stats(sd, this_cpu, idle, sd_idle, cpus,
+ balance, &sds);
+
+ /* Cases where imbalance does not exist from POV of this_cpu */
+ /* 1) this_cpu is not the appropriate cpu to perform load balancing
+ * at this level.
+ * 2) There is no busy sibling group to pull from.
+ * 3) This group is the busiest group.
+ * 4) This group is more busy than the avg busieness at this
+ * sched_domain.
+ * 5) The imbalance is within the specified limit.
+ * 6) Any rebalance would lead to ping-pong
+ */
+ if (balance && !(*balance))
+ goto ret;
- return busiest;
+ if (!sds.busiest || sds.busiest_nr_running == 0)
+ goto out_balanced;
-out_balanced:
-#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
- if (idle == CPU_NOT_IDLE || !(sd->flags & SD_POWERSAVINGS_BALANCE))
- goto ret;
+ if (sds.this_load >= sds.max_load)
+ goto out_balanced;
- if (this == group_leader && group_leader != group_min) {
- *imbalance = min_load_per_task;
- if (sched_mc_power_savings >= POWERSAVINGS_BALANCE_WAKEUP) {
- cpu_rq(this_cpu)->rd->sched_mc_preferred_wakeup_cpu =
- cpumask_first(sched_group_cpus(group_leader));
- }
- return group_min;
- }
-#endif
+ sds.avg_load = (SCHED_LOAD_SCALE * sds.total_load) / sds.total_pwr;
+
+ if (sds.this_load >= sds.avg_load)
+ goto out_balanced;
+
+ if (100 * sds.max_load <= sd->imbalance_pct * sds.this_load)
+ goto out_balanced;
+
+ sds.busiest_load_per_task /= sds.busiest_nr_running;
+ if (sds.group_imb)
+ sds.busiest_load_per_task =
+ min(sds.busiest_load_per_task, sds.avg_load);
+
+ /*
+ * We're trying to get all the cpus to the average_load, so we don't
+ * want to push ourselves above the average load, nor do we wish to
+ * reduce the max loaded cpu below the average load, as either of these
+ * actions would just result in more rebalancing later, and ping-pong
+ * tasks around. Thus we look for the minimum possible imbalance.
+ * Negative imbalances (*we* are more loaded than anyone else) will
+ * be counted as no imbalance for these purposes -- we can't fix that
+ * by pulling tasks to us. Be careful of negative numbers as they'll
+ * appear as very large values with unsigned longs.
+ */
+ if (sds.max_load <= sds.busiest_load_per_task)
+ goto out_balanced;
+
+ /* Looks like there is an imbalance. Compute it */
+ calculate_imbalance(&sds, this_cpu, imbalance);
+ return sds.busiest;
+
+out_balanced:
+ /*
+ * There is no obvious imbalance. But check if we can do some balancing
+ * to save power.
+ */
+ if (check_power_save_busiest_group(&sds, this_cpu, imbalance))
+ return sds.busiest;
ret:
*imbalance = 0;
return NULL;
int cpu = smp_processor_id();
if (stop_tick) {
- cpumask_set_cpu(cpu, nohz.cpu_mask);
cpu_rq(cpu)->in_nohz_recently = 1;
- /*
- * If we are going offline and still the leader, give up!
- */
- if (!cpu_active(cpu) &&
- atomic_read(&nohz.load_balancer) == cpu) {
+ if (!cpu_active(cpu)) {
+ if (atomic_read(&nohz.load_balancer) != cpu)
+ return 0;
+
+ /*
+ * If we are going offline and still the leader,
+ * give up!
+ */
if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu)
BUG();
+
return 0;
}
+ cpumask_set_cpu(cpu, nohz.cpu_mask);
+
/* time for ilb owner also to sleep */
if (cpumask_weight(nohz.cpu_mask) == num_online_cpus()) {
if (atomic_read(&nohz.load_balancer) == cpu)
#endif
}
+static inline int on_null_domain(int cpu)
+{
+ return !rcu_dereference(cpu_rq(cpu)->sd);
+}
+
/*
* Trigger the SCHED_SOFTIRQ if it is time to do periodic load balancing.
*
cpumask_test_cpu(cpu, nohz.cpu_mask))
return;
#endif
- if (time_after_eq(jiffies, rq->next_balance))
+ /* Don't need to rebalance while attached to NULL domain */
+ if (time_after_eq(jiffies, rq->next_balance) &&
+ likely(!on_null_domain(cpu)))
raise_softirq(SCHED_SOFTIRQ);
}
#endif
}
+static void put_prev_task(struct rq *rq, struct task_struct *prev)
+{
+ if (prev->state == TASK_RUNNING) {
+ u64 runtime = prev->se.sum_exec_runtime;
+
+ runtime -= prev->se.prev_sum_exec_runtime;
+ runtime = min_t(u64, runtime, 2*sysctl_sched_migration_cost);
+
+ /*
+ * In order to avoid avg_overlap growing stale when we are
+ * indeed overlapping and hence not getting put to sleep, grow
+ * the avg_overlap on preemption.
+ *
+ * We use the average preemption runtime because that
+ * correlates to the amount of cache footprint a task can
+ * build up.
+ */
+ update_avg(&prev->se.avg_overlap, runtime);
+ }
+ prev->sched_class->put_prev_task(rq, prev);
+}
+
/*
* Pick up the highest-prio task:
*/
static inline struct task_struct *
-pick_next_task(struct rq *rq, struct task_struct *prev)
+pick_next_task(struct rq *rq)
{
const struct sched_class *class;
struct task_struct *p;
/*
* schedule() is the main scheduler function.
*/
- asmlinkage void __sched schedule(void)
+ asmlinkage void __sched __schedule(void)
{
struct task_struct *prev, *next;
unsigned long *switch_count;
struct rq *rq;
int cpu;
- need_resched:
- preempt_disable();
cpu = smp_processor_id();
rq = cpu_rq(cpu);
rcu_qsctr_inc(cpu);
if (unlikely(!rq->nr_running))
idle_balance(cpu, rq);
- prev->sched_class->put_prev_task(rq, prev);
- next = pick_next_task(rq, prev);
+ put_prev_task(rq, prev);
+ next = pick_next_task(rq);
if (likely(prev != next)) {
sched_info_switch(prev, next);
if (unlikely(reacquire_kernel_lock(current) < 0))
goto need_resched_nonpreemptible;
+ }
+ asmlinkage void __sched schedule(void)
+ {
+ need_resched:
+ preempt_disable();
+ __schedule();
preempt_enable_no_resched();
if (unlikely(test_thread_flag(TIF_NEED_RESCHED)))
goto need_resched;
}
EXPORT_SYMBOL(schedule);
+ #ifdef CONFIG_SMP
+ /*
+ * Look out! "owner" is an entirely speculative pointer
+ * access and not reliable.
+ */
+ int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner)
+ {
+ unsigned int cpu;
+ struct rq *rq;
+
+ if (!sched_feat(OWNER_SPIN))
+ return 0;
+
+ #ifdef CONFIG_DEBUG_PAGEALLOC
+ /*
+ * Need to access the cpu field knowing that
+ * DEBUG_PAGEALLOC could have unmapped it if
+ * the mutex owner just released it and exited.
+ */
+ if (probe_kernel_address(&owner->cpu, cpu))
+ goto out;
+ #else
+ cpu = owner->cpu;
+ #endif
+
+ /*
+ * Even if the access succeeded (likely case),
+ * the cpu field may no longer be valid.
+ */
+ if (cpu >= nr_cpumask_bits)
+ goto out;
+
+ /*
+ * We need to validate that we can do a
+ * get_cpu() and that we have the percpu area.
+ */
+ if (!cpu_online(cpu))
+ goto out;
+
+ rq = cpu_rq(cpu);
+
+ for (;;) {
+ /*
+ * Owner changed, break to re-assess state.
+ */
+ if (lock->owner != owner)
+ break;
+
+ /*
+ * Is that owner really running on that cpu?
+ */
+ if (task_thread_info(rq->curr) != owner || need_resched())
+ return 0;
+
+ cpu_relax();
+ }
+ out:
+ return 1;
+ }
+ #endif
+
#ifdef CONFIG_PREEMPT
/*
* this is the entry point to schedule() from in-kernel preemption
* between schedule and now.
*/
barrier();
- } while (unlikely(test_thread_flag(TIF_NEED_RESCHED)));
+ } while (need_resched());
}
EXPORT_SYMBOL(preempt_schedule);
* between schedule and now.
*/
barrier();
- } while (unlikely(test_thread_flag(TIF_NEED_RESCHED)));
+ } while (need_resched());
}
#endif /* CONFIG_PREEMPT */
if (increment > 40)
increment = 40;
- nice = PRIO_TO_NICE(current->static_prio) + increment;
+ nice = TASK_NICE(current) + increment;
if (nice < -20)
nice = -20;
if (nice > 19)
printk(KERN_CONT " %016lx ", thread_saved_pc(p));
#endif
#ifdef CONFIG_DEBUG_STACK_USAGE
- {
- unsigned long *n = end_of_stack(p);
- while (!*n)
- n++;
- free = (unsigned long)n - (unsigned long)end_of_stack(p);
- }
+ free = stack_not_used(p);
#endif
printk(KERN_CONT "%5lu %5d %6d\n", free,
task_pid_nr(p), task_pid_nr(p->real_parent));
if (!rq->nr_running)
break;
update_rq_clock(rq);
- next = pick_next_task(rq, rq->curr);
+ next = pick_next_task(rq);
if (!next)
break;
next->sched_class->put_prev_task(rq, next);
static void rq_attach_root(struct rq *rq, struct root_domain *rd)
{
+ struct root_domain *old_rd = NULL;
unsigned long flags;
spin_lock_irqsave(&rq->lock, flags);
if (rq->rd) {
- struct root_domain *old_rd = rq->rd;
+ old_rd = rq->rd;
if (cpumask_test_cpu(rq->cpu, old_rd->online))
set_rq_offline(rq);
cpumask_clear_cpu(rq->cpu, old_rd->span);
- if (atomic_dec_and_test(&old_rd->refcount))
- free_rootdomain(old_rd);
+ /*
+ * If we dont want to free the old_rt yet then
+ * set old_rd to NULL to skip the freeing later
+ * in this function:
+ */
+ if (!atomic_dec_and_test(&old_rd->refcount))
+ old_rd = NULL;
}
atomic_inc(&rd->refcount);
set_rq_online(rq);
spin_unlock_irqrestore(&rq->lock, flags);
+
+ if (old_rd)
+ free_rootdomain(old_rd);
}
static int __init_refok init_rootdomain(struct root_domain *rd, bool bootmem)
__set_bit(MAX_RT_PRIO, array->bitmap);
#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
- rt_rq->highest_prio = MAX_RT_PRIO;
+ rt_rq->highest_prio.curr = MAX_RT_PRIO;
+#ifdef CONFIG_SMP
+ rt_rq->highest_prio.next = MAX_RT_PRIO;
+#endif
#endif
#ifdef CONFIG_SMP
rt_rq->rt_nr_migratory = 0;
rt_rq->overloaded = 0;
+ plist_head_init(&rq->rt.pushable_tasks, &rq->lock);
#endif
rt_rq->rt_time = 0;
return ret;
}
+
+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 */
+ if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0)
+ return 0;
+
+ return 1;
+}
+
#else /* !CONFIG_RT_GROUP_SCHED */
static int sched_rt_global_constraints(void)
{
struct task_struct *tsk)
{
#ifdef CONFIG_RT_GROUP_SCHED
- /* Don't accept realtime tasks when there is no way for them to run */
- if (rt_task(tsk) && cgroup_tg(cgrp)->rt_bandwidth.rt_runtime == 0)
+ if (!sched_rt_can_attach(cgroup_tg(cgrp), tsk))
return -EINVAL;
#else
/* We don't support RT-tasks being in separate groups */
static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu)
{
- u64 *cpuusage = percpu_ptr(ca->cpuusage, cpu);
+ u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
u64 data;
#ifndef CONFIG_64BIT
static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val)
{
- u64 *cpuusage = percpu_ptr(ca->cpuusage, cpu);
+ u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
#ifndef CONFIG_64BIT
/*
struct cpuacct *ca;
int cpu;
- if (!cpuacct_subsys.active)
+ if (unlikely(!cpuacct_subsys.active))
return;
cpu = task_cpu(tsk);
ca = task_ca(tsk);
for (; ca; ca = ca->parent) {
- u64 *cpuusage = percpu_ptr(ca->cpuusage, cpu);
+ u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
*cpuusage += cputime;
}
}
projects / karo-tx-linux.git / commitdiff