sched: Remove debugging check

[mv-sheeva.git] / kernel / sched_fair.c

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index f4f6a8326dd01ffc0353b369bbfddf5a4f0e2fde..00ebd7686676bd87a6e5b3be513d27028e518796 100644 (file)
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -1654,12 +1654,6 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_
        struct cfs_rq *cfs_rq = task_cfs_rq(curr);
        int scale = cfs_rq->nr_running >= sched_nr_latency;
 
-       if (unlikely(rt_prio(p->prio)))
-               goto preempt;
-
-       if (unlikely(p->sched_class != &fair_sched_class))
-               return;
-
        if (unlikely(se == pse))
                return;
 
@@ -1764,10 +1758,6 @@ static void pull_task(struct rq *src_rq, struct task_struct *p,
        set_task_cpu(p, this_cpu);
        activate_task(this_rq, p, 0);
        check_preempt_curr(this_rq, p, 0);
-
-       /* re-arm NEWIDLE balancing when moving tasks */
-       src_rq->avg_idle = this_rq->avg_idle = 2*sysctl_sched_migration_cost;
-       this_rq->idle_stamp = 0;
 }
 
 /*
@@ -2035,13 +2025,16 @@ struct sd_lb_stats {
        unsigned long this_load_per_task;
        unsigned long this_nr_running;
        unsigned long this_has_capacity;
+       unsigned int  this_idle_cpus;
 
        /* Statistics of the busiest group */
+       unsigned int  busiest_idle_cpus;
        unsigned long max_load;
        unsigned long busiest_load_per_task;
        unsigned long busiest_nr_running;
        unsigned long busiest_group_capacity;
        unsigned long busiest_has_capacity;
+       unsigned int  busiest_group_weight;
 
        int group_imb; /* Is there imbalance in this sd */
 #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
@@ -2063,6 +2056,8 @@ struct sg_lb_stats {
        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;
+       unsigned long idle_cpus;
+       unsigned long group_weight;
        int group_imb; /* Is there an imbalance in the group ? */
        int group_has_capacity; /* Is there extra capacity in the group? */
 };
@@ -2431,7 +2426,8 @@ static inline void update_sg_lb_stats(struct sched_domain *sd,
                sgs->group_load += load;
                sgs->sum_nr_running += rq->nr_running;
                sgs->sum_weighted_load += weighted_cpuload(i);
-
+               if (idle_cpu(i))
+                       sgs->idle_cpus++;
        }
 
        /*
@@ -2469,6 +2465,7 @@ static inline void update_sg_lb_stats(struct sched_domain *sd,
        sgs->group_capacity = DIV_ROUND_CLOSEST(group->cpu_power, SCHED_LOAD_SCALE);
        if (!sgs->group_capacity)
                sgs->group_capacity = fix_small_capacity(sd, group);
+       sgs->group_weight = group->group_weight;
 
        if (sgs->group_capacity > sgs->sum_nr_running)
                sgs->group_has_capacity = 1;
@@ -2576,13 +2573,16 @@ static inline void update_sd_lb_stats(struct sched_domain *sd, int this_cpu,
                        sds->this_nr_running = sgs.sum_nr_running;
                        sds->this_load_per_task = sgs.sum_weighted_load;
                        sds->this_has_capacity = sgs.group_has_capacity;
+                       sds->this_idle_cpus = sgs.idle_cpus;
                } else if (update_sd_pick_busiest(sd, sds, sg, &sgs, this_cpu)) {
                        sds->max_load = sgs.avg_load;
                        sds->busiest = sg;
                        sds->busiest_nr_running = sgs.sum_nr_running;
+                       sds->busiest_idle_cpus = sgs.idle_cpus;
                        sds->busiest_group_capacity = sgs.group_capacity;
                        sds->busiest_load_per_task = sgs.sum_weighted_load;
                        sds->busiest_has_capacity = sgs.group_has_capacity;
+                       sds->busiest_group_weight = sgs.group_weight;
                        sds->group_imb = sgs.group_imb;
                }
 
@@ -2860,8 +2860,26 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
        if (sds.this_load >= sds.avg_load)
                goto out_balanced;
 
-       if (100 * sds.max_load <= sd->imbalance_pct * sds.this_load)
-               goto out_balanced;
+       /*
+        * In the CPU_NEWLY_IDLE, use imbalance_pct to be conservative.
+        * And to check for busy balance use !idle_cpu instead of
+        * CPU_NOT_IDLE. This is because HT siblings will use CPU_NOT_IDLE
+        * even when they are idle.
+        */
+       if (idle == CPU_NEWLY_IDLE || !idle_cpu(this_cpu)) {
+               if (100 * sds.max_load <= sd->imbalance_pct * sds.this_load)
+                       goto out_balanced;
+       } else {
+               /*
+                * 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.
+                */
+               if ((sds.this_idle_cpus  <= sds.busiest_idle_cpus + 1) &&
+                   sds.busiest_nr_running <= sds.busiest_group_weight)
+                       goto out_balanced;
+       }
 
 force_balance:
        /* Looks like there is an imbalance. Compute it */
@@ -3197,8 +3215,10 @@ static void idle_balance(int this_cpu, struct rq *this_rq)
                interval = msecs_to_jiffies(sd->balance_interval);
                if (time_after(next_balance, sd->last_balance + interval))
                        next_balance = sd->last_balance + interval;
-               if (pulled_task)
+               if (pulled_task) {
+                       this_rq->idle_stamp = 0;
                        break;
+               }
        }
 
        raw_spin_lock(&this_rq->lock);