sched: Remove the sched_class load_balance methods

Take out the sched_class methods for load-balancing.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 37 insertions, 29 deletions

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 5116b81d7727..faf9a2f099ab 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -1851,6 +1851,24 @@ static struct task_struct *load_balance_next_fair(void *arg)
         return __load_balance_iterator(cfs_rq, cfs_rq->balance_iterator);
 }
 
+/*
+ * runqueue iterator, to support SMP load-balancing between different
+ * scheduling classes, without having to expose their internal data
+ * structures to the load-balancing proper:
+ */
+struct rq_iterator {
+        void *arg;
+        struct task_struct *(*start)(void *);
+        struct task_struct *(*next)(void *);
+};
+
+static unsigned long
+balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
+                unsigned long max_load_move, struct sched_domain *sd,
+                enum cpu_idle_type idle, int *all_pinned,
+                int *this_best_prio, struct rq_iterator *iterator);
+
+
 static unsigned long
 __load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
                 unsigned long max_load_move, struct sched_domain *sd,
@@ -1929,8 +1947,20 @@ load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
 #endif
 
 static int
-move_one_task_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
-                   struct sched_domain *sd, enum cpu_idle_type idle)
+iter_move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest,
+                struct sched_domain *sd, enum cpu_idle_type idle,
+                struct rq_iterator *iterator);
+
+/*
+ * move_one_task tries to move exactly one task from busiest to this_rq, as
+ * part of active balancing operations within "domain".
+ * Returns 1 if successful and 0 otherwise.
+ *
+ * Called with both runqueues locked.
+ */
+static int
+move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest,
+              struct sched_domain *sd, enum cpu_idle_type idle)
 {
         struct cfs_rq *busy_cfs_rq;
         struct rq_iterator cfs_rq_iterator;
@@ -2094,16 +2124,15 @@ static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
                       struct sched_domain *sd, enum cpu_idle_type idle,
                       int *all_pinned)
 {
-        const struct sched_class *class = sched_class_highest;
-        unsigned long total_load_moved = 0;
+        unsigned long total_load_moved = 0, load_moved;
         int this_best_prio = this_rq->curr->prio;
 
         do {
-                total_load_moved +=
-                        class->load_balance(this_rq, this_cpu, busiest,
+                load_moved = load_balance_fair(this_rq, this_cpu, busiest,
                                 max_load_move - total_load_moved,
                                 sd, idle, all_pinned, &this_best_prio);
-                class = class->next;
+
+                total_load_moved += load_moved;
 
 #ifdef CONFIG_PREEMPT
                 /*
@@ -2114,7 +2143,7 @@ static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
                 if (idle == CPU_NEWLY_IDLE && this_rq->nr_running)
                         break;
 #endif
-        } while (class && max_load_move > total_load_moved);
+        } while (load_moved && max_load_move > total_load_moved);
 
         return total_load_moved > 0;
 }
@@ -2145,25 +2174,6 @@ iter_move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest,
         return 0;
 }
 
-/*
- * move_one_task tries to move exactly one task from busiest to this_rq, as
- * part of active balancing operations within "domain".
- * Returns 1 if successful and 0 otherwise.
- *
- * Called with both runqueues locked.
- */
-static int move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest,
-                         struct sched_domain *sd, enum cpu_idle_type idle)
-{
-        const struct sched_class *class;
-
-        for_each_class(class) {
-                if (class->move_one_task(this_rq, this_cpu, busiest, sd, idle))
-                        return 1;
-        }
-
-        return 0;
-}
 /********** Helpers for find_busiest_group ************************/
 /*
  * sd_lb_stats - Structure to store the statistics of a sched_domain
@@ -3873,8 +3883,6 @@ static const struct sched_class fair_sched_class = {
 #ifdef CONFIG_SMP
         .select_task_rq         = select_task_rq_fair,
 
-        .load_balance           = load_balance_fair,
-        .move_one_task          = move_one_task_fair,
         .rq_online              = rq_online_fair,
         .rq_offline             = rq_offline_fair,