sched: Fix more load-balancing fallout

[linux-flexiantxendom0-3.2.10.git] / kernel / sched / fair.c

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 0d97ebd..e955364 100644 (file)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -784,7 +784,7 @@ account_entity_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
                update_load_add(&rq_of(cfs_rq)->load, se->load.weight);
 #ifdef CONFIG_SMP
        if (entity_is_task(se))
-               list_add_tail(&se->group_node, &rq_of(cfs_rq)->cfs_tasks);
+               list_add(&se->group_node, &rq_of(cfs_rq)->cfs_tasks);
 #endif
        cfs_rq->nr_running++;
 }
@@ -3215,6 +3215,8 @@ static int move_one_task(struct lb_env *env)
 
 static unsigned long task_h_load(struct task_struct *p);
 
+static const unsigned int sched_nr_migrate_break = 32;
+
 /*
  * move_tasks tries to move up to load_move weighted load from busiest to
  * this_rq, as part of a balancing operation within domain "sd".
@@ -3242,7 +3244,7 @@ static int move_tasks(struct lb_env *env)
 
                /* take a breather every nr_migrate tasks */
                if (env->loop > env->loop_break) {
-                       env->loop_break += sysctl_sched_nr_migrate;
+                       env->loop_break += sched_nr_migrate_break;
                        env->flags |= LBF_NEED_BREAK;
                        break;
                }
@@ -3252,7 +3254,7 @@ static int move_tasks(struct lb_env *env)
 
                load = task_h_load(p);
 
-               if (load < 16 && !env->sd->nr_balance_failed)
+               if (sched_feat(LB_MIN) && load < 16 && !env->sd->nr_balance_failed)
                        goto next;
 
                if ((load / 2) > env->load_move)
@@ -4407,7 +4409,7 @@ static int load_balance(int this_cpu, struct rq *this_rq,
                .dst_cpu        = this_cpu,
                .dst_rq         = this_rq,
                .idle           = idle,
-               .loop_break     = sysctl_sched_nr_migrate,
+               .loop_break     = sched_nr_migrate_break,
        };
 
        cpumask_copy(cpus, cpu_active_mask);
@@ -4445,10 +4447,10 @@ redo:
                 * correctly treated as an imbalance.
                 */
                env.flags |= LBF_ALL_PINNED;
-               env.load_move = imbalance;
-               env.src_cpu = busiest->cpu;
-               env.src_rq = busiest;
-               env.loop_max = busiest->nr_running;
+               env.load_move   = imbalance;
+               env.src_cpu     = busiest->cpu;
+               env.src_rq      = busiest;
+               env.loop_max    = min_t(unsigned long, sysctl_sched_nr_migrate, busiest->nr_running);
 
 more_balance:
                local_irq_save(flags);