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>

5 files changed, 37 insertions, 104 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index f2f842db03ce..50d685cde70e 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1087,14 +1087,6 @@ struct sched_class {
 #ifdef CONFIG_SMP
         int  (*select_task_rq)(struct task_struct *p, int sd_flag, int flags);
 
-        unsigned long (*load_balance) (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);
-
-        int (*move_one_task) (struct rq *this_rq, int this_cpu,
-                              struct rq *busiest, struct sched_domain *sd,
-                              enum cpu_idle_type idle);
         void (*pre_schedule) (struct rq *this_rq, struct task_struct *task);
         void (*post_schedule) (struct rq *this_rq);
         void (*task_waking) (struct rq *this_rq, struct task_struct *task);
diff --git a/kernel/sched.c b/kernel/sched.c
index 13a2acf18b2d..c0be07932a8d 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1390,32 +1390,6 @@ static const u32 prio_to_wmult[40] = {
  /*  15 */ 119304647, 148102320, 186737708, 238609294, 286331153,
 };
 
-static void activate_task(struct rq *rq, struct task_struct *p, int wakeup);
-
-/*
- * 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 *);
-};
-
-#ifdef CONFIG_SMP
-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 int
-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);
-#endif
-
 /* Time spent by the tasks of the cpu accounting group executing in ... */
 enum cpuacct_stat_index {
         CPUACCT_STAT_USER,      /* ... user mode */
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,
 
diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c
index 01332bfc61a7..a8a6d8a50947 100644
--- a/kernel/sched_idletask.c
+++ b/kernel/sched_idletask.c
@@ -44,24 +44,6 @@ static void put_prev_task_idle(struct rq *rq, struct task_struct *prev)
 {
 }
 
-#ifdef CONFIG_SMP
-static unsigned long
-load_balance_idle(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)
-{
-        return 0;
-}
-
-static int
-move_one_task_idle(struct rq *this_rq, int this_cpu, struct rq *busiest,
-                   struct sched_domain *sd, enum cpu_idle_type idle)
-{
-        return 0;
-}
-#endif
-
 static void task_tick_idle(struct rq *rq, struct task_struct *curr, int queued)
 {
 }
@@ -119,9 +101,6 @@ static const struct sched_class idle_sched_class = {
 
 #ifdef CONFIG_SMP
         .select_task_rq         = select_task_rq_idle,
-
-        .load_balance           = load_balance_idle,
-        .move_one_task          = move_one_task_idle,
 #endif
 
         .set_curr_task          = set_curr_task_idle,
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 072b3fcee8d8..502bb614e40a 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -1481,24 +1481,6 @@ static void task_woken_rt(struct rq *rq, struct task_struct *p)
                 push_rt_tasks(rq);
 }
 
-static unsigned long
-load_balance_rt(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)
-{
-        /* don't touch RT tasks */
-        return 0;
-}
-
-static int
-move_one_task_rt(struct rq *this_rq, int this_cpu, struct rq *busiest,
-                 struct sched_domain *sd, enum cpu_idle_type idle)
-{
-        /* don't touch RT tasks */
-        return 0;
-}
-
 static void set_cpus_allowed_rt(struct task_struct *p,
                                 const struct cpumask *new_mask)
 {
@@ -1746,8 +1728,6 @@ static const struct sched_class rt_sched_class = {
 #ifdef CONFIG_SMP
         .select_task_rq         = select_task_rq_rt,
 
-        .load_balance           = load_balance_rt,
-        .move_one_task          = move_one_task_rt,
         .set_cpus_allowed       = set_cpus_allowed_rt,
         .rq_online              = rq_online_rt,
         .rq_offline             = rq_offline_rt,