#include <linux/latencytop.h>
#include <linux/sched.h>
#include <linux/cpumask.h>
+#include <linux/cpuidle.h>
#include <linux/slab.h>
#include <linux/profile.h>
#include <linux/interrupt.h>
}
#ifdef CONFIG_SMP
+static int select_idle_sibling(struct task_struct *p, int cpu);
static unsigned long task_h_load(struct task_struct *p);
static inline void __update_task_entity_contrib(struct sched_entity *se);
if (load_too_imbalanced(src_load, dst_load, env))
goto unlock;
+ /*
+ * One idle CPU per node is evaluated for a task numa move.
+ * Call select_idle_sibling to maybe find a better one.
+ */
+ if (!cur)
+ env->dst_cpu = select_idle_sibling(env->p, env->dst_cpu);
+
assign:
task_numa_assign(env, cur, imp);
unlock:
if (!p->mm)
return;
- /* Do not worry about placement if exiting */
- if (p->state == TASK_DEAD)
- return;
-
/* Allocate buffer to track faults on a per-node basis */
if (unlikely(!p->numa_faults_memory)) {
int size = sizeof(*p->numa_faults_memory) *
vma = mm->mmap;
}
for (; vma; vma = vma->vm_next) {
- if (!vma_migratable(vma) || !vma_policy_mof(p, vma))
+ if (!vma_migratable(vma) || !vma_policy_mof(vma))
continue;
/*
/*
* As y^PERIOD = 1/2, we can combine
- * y^n = 1/2^(n/PERIOD) * k^(n%PERIOD)
- * With a look-up table which covers
k^n (n<PERIOD)
+ * y^n = 1/2^(n/PERIOD) * y^(n%PERIOD)
+ * With a look-up table which covers
y^n (n<PERIOD)
*
* To achieve constant time decay_load.
*/
static unsigned long cpu_avg_load_per_task(int cpu)
{
struct rq *rq = cpu_rq(cpu);
- unsigned long nr_running = ACCESS_ONCE(rq->nr_running);
+ unsigned long nr_running = ACCESS_ONCE(rq->cfs.h_nr_running);
unsigned long load_avg = rq->cfs.runnable_load_avg;
if (nr_running)
static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
{
s64 this_load, load;
+ s64 this_eff_load, prev_eff_load;
int idx, this_cpu, prev_cpu;
- unsigned long tl_per_task;
struct task_group *tg;
unsigned long weight;
int balanced;
* Otherwise check if either cpus are near enough in load to allow this
* task to be woken on this_cpu.
*/
- if (this_load > 0) {
- s64 this_eff_load, prev_eff_load;
+ this_eff_load = 100;
+ this_eff_load *= capacity_of(prev_cpu);
- this_eff_load = 100;
- this_eff_load *= capacity_of(prev_cpu);
+ prev_eff_load = 100 + (sd->imbalance_pct - 100) / 2;
+ prev_eff_load *= capacity_of(this_cpu);
+
+ if (this_load > 0) {
this_eff_load *= this_load +
effective_load(tg, this_cpu, weight, weight);
- prev_eff_load = 100 + (sd->imbalance_pct - 100) / 2;
- prev_eff_load *= capacity_of(this_cpu);
prev_eff_load *= load + effective_load(tg, prev_cpu, 0, weight);
+ }
- balanced = this_eff_load <= prev_eff_load;
- } else
- balanced = true;
-
- /*
- * If the currently running task will sleep within
- * a reasonable amount of time then attract this newly
- * woken task:
- */
- if (sync && balanced)
- return 1;
+ balanced = this_eff_load <= prev_eff_load;
schedstat_inc(p, se.statistics.nr_wakeups_affine_attempts);
- tl_per_task = cpu_avg_load_per_task(this_cpu);
- if (balanced ||
- (this_load <= load &&
- this_load + target_load(prev_cpu, idx) <= tl_per_task)) {
- /*
- * This domain has SD_WAKE_AFFINE and
- * p is cache cold in this domain, and
- * there is no bad imbalance.
- */
- schedstat_inc(sd, ttwu_move_affine);
- schedstat_inc(p, se.statistics.nr_wakeups_affine);
+ if (!balanced)
+ return 0;
- return 1;
- }
- return 0;
+ schedstat_inc(sd, ttwu_move_affine);
+ schedstat_inc(p, se.statistics.nr_wakeups_affine);
+
+ return 1;
}
/*
find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu)
{
unsigned long load, min_load = ULONG_MAX;
- int idlest = -1;
+ unsigned int min_exit_latency = UINT_MAX;
+ u64 latest_idle_timestamp = 0;
+ int least_loaded_cpu = this_cpu;
+ int shallowest_idle_cpu = -1;
int i;
/* Traverse only the allowed CPUs */
for_each_cpu_and(i, sched_group_cpus(group), tsk_cpus_allowed(p)) {
- load = weighted_cpuload(i);
-
- if (load < min_load || (load == min_load && i == this_cpu)) {
- min_load = load;
- idlest = i;
+ if (idle_cpu(i)) {
+ struct rq *rq = cpu_rq(i);
+ struct cpuidle_state *idle = idle_get_state(rq);
+ if (idle && idle->exit_latency < min_exit_latency) {
+ /*
+ * We give priority to a CPU whose idle state
+ * has the smallest exit latency irrespective
+ * of any idle timestamp.
+ */
+ min_exit_latency = idle->exit_latency;
+ latest_idle_timestamp = rq->idle_stamp;
+ shallowest_idle_cpu = i;
+ } else if ((!idle || idle->exit_latency == min_exit_latency) &&
+ rq->idle_stamp > latest_idle_timestamp) {
+ /*
+ * If equal or no active idle state, then
+ * the most recently idled CPU might have
+ * a warmer cache.
+ */
+ latest_idle_timestamp = rq->idle_stamp;
+ shallowest_idle_cpu = i;
+ }
+ } else {
+ load = weighted_cpuload(i);
+ if (load < min_load || (load == min_load && i == this_cpu)) {
+ min_load = load;
+ least_loaded_cpu = i;
+ }
}
}
- return idlest;
+ return shallowest_idle_cpu != -1 ? shallowest_idle_cpu : least_loaded_cpu;
}
/*
if (p->nr_cpus_allowed == 1)
return prev_cpu;
- if (sd_flag & SD_BALANCE_WAKE) {
- if (cpumask_test_cpu(cpu, tsk_cpus_allowed(p)))
- want_affine = 1;
- new_cpu = prev_cpu;
- }
+ if (sd_flag & SD_BALANCE_WAKE)
+ want_affine = cpumask_test_cpu(cpu, tsk_cpus_allowed(p));
rcu_read_lock();
for_each_domain(cpu, tmp) {
if (!tsk_cache_hot)
tsk_cache_hot = migrate_degrades_locality(p, env);
- if (migrate_improves_locality(p, env)) {
-#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 ||
- env->sd->nr_balance_failed > env->sd->cache_nice_tries) {
-
+ if (migrate_improves_locality(p, env) || !tsk_cache_hot ||
+ env->sd->nr_balance_failed > env->sd->cache_nice_tries) {
if (tsk_cache_hot) {
schedstat_inc(env->sd, lb_hot_gained[env->idle]);
schedstat_inc(p, se.statistics.nr_forced_migrations);
}
-
return 1;
}
return default_scale_capacity(sd, cpu);
}
-static unsigned long default_scale_smt_capacity(struct sched_domain *sd, int cpu)
+static unsigned long default_scale_cpu_capacity(struct sched_domain *sd, int cpu)
{
- unsigned long weight = sd->span_weight;
- unsigned long smt_gain = sd->smt_gain;
-
- smt_gain /= weight;
+ if ((sd->flags & SD_SHARE_CPUCAPACITY) && (sd->span_weight > 1))
+ return sd->smt_gain / sd->span_weight;
- return smt_gain;
+ return SCHED_CAPACITY_SCALE;
}
-unsigned long __weak arch_scale_smt_capacity(struct sched_domain *sd, int cpu)
+unsigned long __weak arch_scale_cpu_capacity(struct sched_domain *sd, int cpu)
{
- return default_scale_smt_capacity(sd, cpu);
+ return default_scale_cpu_capacity(sd, cpu);
}
static unsigned long scale_rt_capacity(int cpu)
static void update_cpu_capacity(struct sched_domain *sd, int cpu)
{
- unsigned long weight = sd->span_weight;
unsigned long capacity = SCHED_CAPACITY_SCALE;
struct sched_group *sdg = sd->groups;
- if ((sd->flags & SD_SHARE_CPUCAPACITY) && weight > 1) {
- if (sched_feat(ARCH_CAPACITY))
- capacity *= arch_scale_smt_capacity(sd, cpu);
- else
- capacity *= default_scale_smt_capacity(sd, cpu);
+ if (sched_feat(ARCH_CAPACITY))
+ capacity *= arch_scale_cpu_capacity(sd, cpu);
+ else
+ capacity *= default_scale_cpu_capacity(sd, cpu);
- capacity >>= SCHED_CAPACITY_SHIFT;
- }
+ capacity >>= SCHED_CAPACITY_SHIFT;
sdg->sgc->capacity_orig = capacity;
load = source_load(i, load_idx);
sgs->group_load += load;
- sgs->sum_nr_running += rq->nr_running;
+ sgs->sum_nr_running += rq->cfs.h_nr_running;
if (rq->nr_running > 1)
*overload = true;
goto force_balance;
/*
- * If the local group is more busy than the selected busiest group
+ * If the local group is busier than the selected busiest group
* don't try and pull any tasks.
*/
if (local->avg_load >= busiest->avg_load)
if (env->idle == CPU_IDLE) {
/*
- * This cpu is idle. If the busiest group load doesn't
- * have more tasks than the number of available cpu's and
- * there is no imbalance between this and busiest group
- * wrt to idle cpu's, it is balanced.
+ * This cpu is idle. If the busiest group is not overloaded
+ * and there is no imbalance between this and busiest group
+ * wrt idle cpus, it is balanced. The imbalance becomes
+ * significant if the diff is greater than 1 otherwise we
+ * might end up to just move the imbalance on another group
*/
- if ((local->idle_cpus < busiest->idle_cpus) &&
- busiest->sum_nr_running <= busiest->group_weight)
+ if ((busiest->group_type != group_overloaded) &&
+ (local->idle_cpus <= (busiest->idle_cpus + 1)))
goto out_balanced;
} else {
/*
local_irq_restore(flags);
- /*
- * 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;
if (sd_parent) {
int *group_imbalance = &sd_parent->groups->sgc->imbalance;
- if ((env.flags & LBF_SOME_PINNED) && env.imbalance > 0) {
+ if ((env.flags & LBF_SOME_PINNED) && env.imbalance > 0)
*group_imbalance = 1;
- } else if (*group_imbalance)
- *group_imbalance = 0;
}
/* All tasks on this runqueue were pinned by CPU affinity */
env.loop_break = sched_nr_migrate_break;
goto redo;
}
- goto out_balanced;
+ goto out_all_pinned;
}
}
goto out;
out_balanced:
+ /*
+ * We reach balance although we may have faced some affinity
+ * constraints. Clear the imbalance flag if it was set.
+ */
+ if (sd_parent) {
+ int *group_imbalance = &sd_parent->groups->sgc->imbalance;
+
+ if (*group_imbalance)
+ *group_imbalance = 0;
+ }
+
+out_all_pinned:
+ /*
+ * We reach balance because all tasks are pinned at this level so
+ * we can't migrate them. Let the imbalance flag set so parent level
+ * can try to migrate them.
+ */
schedstat_inc(sd, lb_balanced[idle]);
sd->nr_balance_failed = 0;
projects / linux-2.6-microblaze.git / blobdiff