* Scheduling class tree data structure manipulation methods:
*/
-static inline u64 max_vruntime(u64 min_vruntime, u64 vruntime)
+static inline u64 max_vruntime(u64 max_vruntime, u64 vruntime)
{
- s64 delta = (s64)(vruntime - min_vruntime);
+ s64 delta = (s64)(vruntime - max_vruntime);
if (delta > 0)
- min_vruntime = vruntime;
+ max_vruntime = vruntime;
- return min_vruntime;
+ return max_vruntime;
}
static inline u64 min_vruntime(u64 min_vruntime, u64 vruntime)
vruntime = min_vruntime(vruntime, se->vruntime);
}
+ /* ensure we never gain time by being placed backwards. */
cfs_rq->min_vruntime = max_vruntime(cfs_rq->min_vruntime, vruntime);
#ifndef CONFIG_64BIT
smp_wmb();
}
/*
- * We calculate the vruntime slice of a to be inserted task
+ * We calculate the vruntime slice of a to-be-inserted task.
*
* vs = s/w
*/
se->avg.decay_count = atomic64_read(&cfs_rq->decay_counter);
} /* migrations, e.g. sleep=0 leave decay_count == 0 */
}
+
+/*
+ * Update the rq's load with the elapsed running time before entering
+ * idle. if the last scheduled task is not a CFS task, idle_enter will
+ * be the only way to update the runnable statistic.
+ */
+void idle_enter_fair(struct rq *this_rq)
+{
+ update_rq_runnable_avg(this_rq, 1);
+}
+
+/*
+ * Update the rq's load with the elapsed idle time before a task is
+ * scheduled. if the newly scheduled task is not a CFS task, idle_exit will
+ * be the only way to update the runnable statistic.
+ */
+void idle_exit_fair(struct rq *this_rq)
+{
+ update_rq_runnable_avg(this_rq, 0);
+}
+
#else
static inline void update_entity_load_avg(struct sched_entity *se,
int update_cfs_rq) {}
int tsk_cache_hot = 0;
/*
* We do not migrate tasks that are:
- * 1) running (obviously), or
+ * 1) throttled_lb_pair, or
* 2) cannot be migrated to this CPU due to cpus_allowed, or
- * 3) are cache-hot on their current CPU.
+ * 3) running (obviously), or
+ * 4) are cache-hot on their current CPU.
*/
+ if (throttled_lb_pair(task_group(p), env->src_cpu, env->dst_cpu))
+ return 0;
+
if (!cpumask_test_cpu(env->dst_cpu, tsk_cpus_allowed(p))) {
- int new_dst_cpu;
+ int cpu;
schedstat_inc(p, se.statistics.nr_failed_migrations_affine);
if (!env->dst_grpmask || (env->flags & LBF_SOME_PINNED))
return 0;
- new_dst_cpu = cpumask_first_and(env->dst_grpmask,
- tsk_cpus_allowed(p));
- if (new_dst_cpu < nr_cpu_ids) {
- env->flags |= LBF_SOME_PINNED;
- env->new_dst_cpu = new_dst_cpu;
+ /* Prevent to re-select dst_cpu via env's cpus */
+ for_each_cpu_and(cpu, env->dst_grpmask, env->cpus) {
+ if (cpumask_test_cpu(cpu, tsk_cpus_allowed(p))) {
+ env->flags |= LBF_SOME_PINNED;
+ env->new_dst_cpu = cpu;
+ break;
+ }
}
+
return 0;
}
tsk_cache_hot = task_hot(p, env->src_rq->clock_task, env->sd);
if (!tsk_cache_hot ||
env->sd->nr_balance_failed > env->sd->cache_nice_tries) {
-#ifdef CONFIG_SCHEDSTATS
+
if (tsk_cache_hot) {
schedstat_inc(env->sd, lb_hot_gained[env->idle]);
schedstat_inc(p, se.statistics.nr_forced_migrations);
}
-#endif
+
return 1;
}
- if (tsk_cache_hot) {
- schedstat_inc(p, se.statistics.nr_failed_migrations_hot);
- return 0;
- }
- return 1;
+ schedstat_inc(p, se.statistics.nr_failed_migrations_hot);
+ return 0;
}
/*
struct task_struct *p, *n;
list_for_each_entry_safe(p, n, &env->src_rq->cfs_tasks, se.group_node) {
- if (throttled_lb_pair(task_group(p), env->src_rq->cpu, env->dst_cpu))
- continue;
-
if (!can_migrate_task(p, env))
continue;
break;
}
- if (throttled_lb_pair(task_group(p), env->src_cpu, env->dst_cpu))
+ if (!can_migrate_task(p, env))
goto next;
load = task_h_load(p);
if ((load / 2) > env->imbalance)
goto next;
- if (!can_migrate_task(p, env))
- goto next;
-
move_task(p, env);
pulled++;
env->imbalance -= load;
return load_idx;
}
-unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu)
+static unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu)
{
return SCHED_POWER_SCALE;
}
return default_scale_freq_power(sd, cpu);
}
-unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu)
+static unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu)
{
unsigned long weight = sd->span_weight;
unsigned long smt_gain = sd->smt_gain;
return default_scale_smt_power(sd, cpu);
}
-unsigned long scale_rt_power(int cpu)
+static unsigned long scale_rt_power(int cpu)
{
struct rq *rq = cpu_rq(cpu);
u64 total, available, age_stamp, avg;
#define MAX_PINNED_INTERVAL 512
/* Working cpumask for load_balance and load_balance_newidle. */
-DEFINE_PER_CPU(cpumask_var_t, load_balance_tmpmask);
+DEFINE_PER_CPU(cpumask_var_t, load_balance_mask);
static int need_active_balance(struct lb_env *env)
{
int *balance)
{
int ld_moved, cur_ld_moved, active_balance = 0;
- int lb_iterations, max_lb_iterations;
struct sched_group *group;
struct rq *busiest;
unsigned long flags;
- struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask);
+ struct cpumask *cpus = __get_cpu_var(load_balance_mask);
struct lb_env env = {
.sd = sd,
.cpus = cpus,
};
+ /*
+ * For NEWLY_IDLE load_balancing, we don't need to consider
+ * other cpus in our group
+ */
+ if (idle == CPU_NEWLY_IDLE)
+ env.dst_grpmask = NULL;
+
cpumask_copy(cpus, cpu_active_mask);
- max_lb_iterations = cpumask_weight(env.dst_grpmask);
schedstat_inc(sd, lb_count[idle]);
schedstat_add(sd, lb_imbalance[idle], env.imbalance);
ld_moved = 0;
- lb_iterations = 1;
if (busiest->nr_running > 1) {
/*
* Attempt to move tasks. If find_busiest_group has found
double_rq_unlock(env.dst_rq, busiest);
local_irq_restore(flags);
- if (env.flags & LBF_NEED_BREAK) {
- env.flags &= ~LBF_NEED_BREAK;
- goto more_balance;
- }
-
/*
* some other cpu did the load balance for us.
*/
if (cur_ld_moved && env.dst_cpu != smp_processor_id())
resched_cpu(env.dst_cpu);
+ if (env.flags & LBF_NEED_BREAK) {
+ env.flags &= ~LBF_NEED_BREAK;
+ goto more_balance;
+ }
+
/*
* Revisit (affine) tasks on src_cpu that couldn't be moved to
* us and move them to an alternate dst_cpu in our sched_group
* moreover subsequent load balance cycles should correct the
* excess load moved.
*/
- if ((env.flags & LBF_SOME_PINNED) && env.imbalance > 0 &&
- lb_iterations++ < max_lb_iterations) {
+ if ((env.flags & LBF_SOME_PINNED) && env.imbalance > 0) {
env.dst_rq = cpu_rq(env.new_dst_cpu);
env.dst_cpu = env.new_dst_cpu;
env.flags &= ~LBF_SOME_PINNED;
env.loop = 0;
env.loop_break = sched_nr_migrate_break;
+
+ /* Prevent to re-select dst_cpu via env's cpus */
+ cpumask_clear_cpu(env.dst_cpu, env.cpus);
+
/*
* Go back to "more_balance" rather than "redo" since we
* need to continue with same src_cpu.
if (this_rq->avg_idle < sysctl_sched_migration_cost)
return;
- update_rq_runnable_avg(this_rq, 1);
-
/*
* Drop the rq->lock, but keep IRQ/preempt disabled.
*/
* It checks each scheduling domain to see if it is due to be balanced,
* and initiates a balancing operation if so.
*
- * Balancing parameters are set up in arch_init_sched_domains.
+ * Balancing parameters are set up in init_sched_domains.
*/
static void rebalance_domains(int cpu, enum cpu_idle_type idle)
{
if (time_after_eq(jiffies, sd->last_balance + interval)) {
if (load_balance(cpu, rq, sd, idle, &balance)) {
/*
- * We've pulled tasks over so either we're no
- * longer idle.
+ * The LBF_SOME_PINNED logic could have changed
+ * env->dst_cpu, so we can't know our idle
+ * state even if we migrated tasks. Update it.
*/
- idle = CPU_NOT_IDLE;
+ idle = idle_cpu(cpu) ? CPU_IDLE : CPU_NOT_IDLE;
}
sd->last_balance = jiffies;
}