if (tg_weight)
shares /= tg_weight;
+ /*
+ * MIN_SHARES has to be unscaled here to support per-CPU partitioning
+ * of a group with small tg->shares value. It is a floor value which is
+ * assigned as a minimum load.weight to the sched_entity representing
+ * the group on a CPU.
+ *
+ * E.g. on 64-bit for a group with tg->shares of scale_load(15)=15*1024
+ * on an 8-core system with 8 tasks each runnable on one CPU shares has
+ * to be 15*1024*1/8=1920 instead of scale_load(MIN_SHARES)=2*1024. In
+ * case no task is runnable on a CPU MIN_SHARES=2 should be returned
+ * instead of 0.
+ */
if (shares < MIN_SHARES)
shares = MIN_SHARES;
if (shares > tg->shares)
static inline int throttled_hierarchy(struct cfs_rq *cfs_rq);
-static void update_cfs_shares(struct cfs_rq *cfs_rq)
+static void update_cfs_shares(struct sched_entity *se)
{
+ struct cfs_rq *cfs_rq = group_cfs_rq(se);
struct task_group *tg;
- struct sched_entity *se;
long shares;
- tg = cfs_rq->tg;
- se = tg->se[cpu_of(rq_of(cfs_rq))];
- if (!se || throttled_hierarchy(cfs_rq))
+ if (!cfs_rq)
+ return;
+
+ if (throttled_hierarchy(cfs_rq))
return;
+
+ tg = cfs_rq->tg;
+
#ifndef CONFIG_SMP
if (likely(se->load.weight == tg->shares))
return;
reweight_entity(cfs_rq_of(se), se, shares);
}
+
#else /* CONFIG_FAIR_GROUP_SCHED */
-static inline void update_cfs_shares(struct cfs_rq *cfs_rq)
+static inline void update_cfs_shares(struct sched_entity *se)
{
}
#endif /* CONFIG_FAIR_GROUP_SCHED */
return cfs_rq->avg.load_avg;
}
-static int idle_balance(struct rq *this_rq);
+static int idle_balance(struct rq *this_rq, struct rq_flags *rf);
#else /* CONFIG_SMP */
static inline void
detach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {}
-static inline int idle_balance(struct rq *rq)
+static inline int idle_balance(struct rq *rq, struct rq_flags *rf)
{
return 0;
}
if (renorm && !curr)
se->vruntime += cfs_rq->min_vruntime;
+ /*
+ * When enqueuing a sched_entity, we must:
+ * - Update loads to have both entity and cfs_rq synced with now.
+ * - Add its load to cfs_rq->runnable_avg
+ * - For group_entity, update its weight to reflect the new share of
+ * its group cfs_rq
+ * - Add its new weight to cfs_rq->load.weight
+ */
update_load_avg(se, UPDATE_TG);
enqueue_entity_load_avg(cfs_rq, se);
+ update_cfs_shares(se);
account_entity_enqueue(cfs_rq, se);
- update_cfs_shares(cfs_rq);
if (flags & ENQUEUE_WAKEUP)
place_entity(cfs_rq, se, 0);
* Update run-time statistics of the 'current'.
*/
update_curr(cfs_rq);
+
+ /*
+ * When dequeuing a sched_entity, we must:
+ * - Update loads to have both entity and cfs_rq synced with now.
+ * - Substract its load from the cfs_rq->runnable_avg.
+ * - Substract its previous weight from cfs_rq->load.weight.
+ * - For group entity, update its weight to reflect the new share
+ * of its group cfs_rq.
+ */
update_load_avg(se, UPDATE_TG);
dequeue_entity_load_avg(cfs_rq, se);
/* return excess runtime on last dequeue */
return_cfs_rq_runtime(cfs_rq);
- update_cfs_shares(cfs_rq);
+ update_cfs_shares(se);
/*
* Now advance min_vruntime if @se was the entity holding it back,
* Ensure that runnable average is periodically updated.
*/
update_load_avg(curr, UPDATE_TG);
- update_cfs_shares(cfs_rq);
+ update_cfs_shares(curr);
#ifdef CONFIG_SCHED_HRTICK
/*
break;
update_load_avg(se, UPDATE_TG);
- update_cfs_shares(cfs_rq);
+ update_cfs_shares(se);
}
if (!se)
break;
update_load_avg(se, UPDATE_TG);
- update_cfs_shares(cfs_rq);
+ update_cfs_shares(se);
}
if (!se)
}
static struct task_struct *
-pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct pin_cookie cookie)
+pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
{
struct cfs_rq *cfs_rq = &rq->cfs;
struct sched_entity *se;
return p;
idle:
- /*
- * This is OK, because current is on_cpu, which avoids it being picked
- * for load-balance and preemption/IRQs are still disabled avoiding
- * further scheduler activity on it and we're being very careful to
- * re-start the picking loop.
- */
- lockdep_unpin_lock(&rq->lock, cookie);
- new_tasks = idle_balance(rq);
- lockdep_repin_lock(&rq->lock, cookie);
+ new_tasks = idle_balance(rq, rf);
+
/*
* Because idle_balance() releases (and re-acquires) rq->lock, it is
* possible for any higher priority task to appear. In that case we
more_balance:
raw_spin_lock_irqsave(&busiest->lock, flags);
+ update_rq_clock(busiest);
/*
* cur_ld_moved - load moved in current iteration
* idle_balance is called by schedule() if this_cpu is about to become
* idle. Attempts to pull tasks from other CPUs.
*/
-static int idle_balance(struct rq *this_rq)
+static int idle_balance(struct rq *this_rq, struct rq_flags *rf)
{
unsigned long next_balance = jiffies + HZ;
int this_cpu = this_rq->cpu;
*/
this_rq->idle_stamp = rq_clock(this_rq);
+ /*
+ * This is OK, because current is on_cpu, which avoids it being picked
+ * for load-balance and preemption/IRQs are still disabled avoiding
+ * further scheduler activity on it and we're being very careful to
+ * re-start the picking loop.
+ */
+ rq_unpin_lock(this_rq, rf);
+
if (this_rq->avg_idle < sysctl_sched_migration_cost ||
!this_rq->rd->overload) {
rcu_read_lock();
if (pulled_task)
this_rq->idle_stamp = 0;
+ rq_repin_lock(this_rq, rf);
+
return pulled_task;
}
};
schedstat_inc(sd->alb_count);
+ update_rq_clock(busiest_rq);
p = detach_one_task(&env);
if (p) {
se = tg->se[i];
raw_spin_lock_irq(&rq->lock);
+ update_rq_clock(rq);
attach_entity_cfs_rq(se);
sync_throttle(tg, i);
raw_spin_unlock_irq(&rq->lock);
/* Possible calls to update_curr() need rq clock */
update_rq_clock(rq);
- for_each_sched_entity(se)
- update_cfs_shares(group_cfs_rq(se));
+ for_each_sched_entity(se) {
+ update_load_avg(se, UPDATE_TG);
+ update_cfs_shares(se);
+ }
raw_spin_unlock_irqrestore(&rq->lock, flags);
}
projects / linux.git / blobdiff