Revert "sched: Introduce temporary FAIR_GROUP_SCHED dependency for load-tracking"

Remove CONFIG_FAIR_GROUP_SCHED that covers the runnable info, then
we can use runnable load variables.

Also remove 2 CONFIG_FAIR_GROUP_SCHED setting which is not in reverted
patch(introduced in 9ee474f), but also need to revert.

Signed-off-by: Alex Shi <alex.shi@intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/51CA76A3.3050207@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

3 files changed, 7 insertions, 36 deletions

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index ceeaf0f45be0..0241b1b55a04 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1611,12 +1611,7 @@ static void __sched_fork(struct task_struct *p)
         p->se.vruntime                  = 0;
         INIT_LIST_HEAD(&p->se.group_node);
 
-/*
- * Load-tracking only depends on SMP, FAIR_GROUP_SCHED dependency below may be
- * removed when useful for applications beyond shares distribution (e.g.
- * load-balance).
- */
-#if defined(CONFIG_SMP) && defined(CONFIG_FAIR_GROUP_SCHED)
+#ifdef CONFIG_SMP
         p->se.avg.runnable_avg_period = 0;
         p->se.avg.runnable_avg_sum = 0;
 #endif
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index c0ac2c3b56e1..36eadaaa4e5b 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1128,8 +1128,7 @@ static inline void update_cfs_shares(struct cfs_rq *cfs_rq)
 }
 #endif /* CONFIG_FAIR_GROUP_SCHED */
 
-/* Only depends on SMP, FAIR_GROUP_SCHED may be removed when useful in lb */
-#if defined(CONFIG_SMP) && defined(CONFIG_FAIR_GROUP_SCHED)
+#ifdef CONFIG_SMP
 /*
  * We choose a half-life close to 1 scheduling period.
  * Note: The tables below are dependent on this value.
@@ -3431,12 +3430,6 @@ unlock:
 }
 
 /*
- * Load-tracking only depends on SMP, FAIR_GROUP_SCHED dependency below may be
- * removed when useful for applications beyond shares distribution (e.g.
- * load-balance).
- */
-#ifdef CONFIG_FAIR_GROUP_SCHED
-/*
  * Called immediately before a task is migrated to a new cpu; task_cpu(p) and
  * cfs_rq_of(p) references at time of call are still valid and identify the
  * previous cpu.  However, the caller only guarantees p->pi_lock is held; no
@@ -3459,7 +3452,6 @@ migrate_task_rq_fair(struct task_struct *p, int next_cpu)
                 atomic64_add(se->avg.load_avg_contrib, &cfs_rq->removed_load);
         }
 }
-#endif
 #endif /* CONFIG_SMP */
 
 static unsigned long
@@ -5861,7 +5853,7 @@ static void switched_from_fair(struct rq *rq, struct task_struct *p)
                 se->vruntime -= cfs_rq->min_vruntime;
         }
 
-#if defined(CONFIG_FAIR_GROUP_SCHED) && defined(CONFIG_SMP)
+#ifdef CONFIG_SMP
         /*
         * Remove our load from contribution when we leave sched_fair
         * and ensure we don't carry in an old decay_count if we
@@ -5920,7 +5912,7 @@ void init_cfs_rq(struct cfs_rq *cfs_rq)
 #ifndef CONFIG_64BIT
         cfs_rq->min_vruntime_copy = cfs_rq->min_vruntime;
 #endif
-#if defined(CONFIG_FAIR_GROUP_SCHED) && defined(CONFIG_SMP)
+#ifdef CONFIG_SMP
         atomic64_set(&cfs_rq->decay_counter, 1);
         atomic64_set(&cfs_rq->removed_load, 0);
 #endif
@@ -6162,9 +6154,8 @@ const struct sched_class fair_sched_class = {
 
 #ifdef CONFIG_SMP
         .select_task_rq         = select_task_rq_fair,
-#ifdef CONFIG_FAIR_GROUP_SCHED
         .migrate_task_rq        = migrate_task_rq_fair,
-#endif
+
         .rq_online              = rq_online_fair,
         .rq_offline             = rq_offline_fair,
 
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 029601a61587..77ce668ba302 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -269,12 +269,6 @@ struct cfs_rq {
 #endif
 
 #ifdef CONFIG_SMP
-/*
- * Load-tracking only depends on SMP, FAIR_GROUP_SCHED dependency below may be
- * removed when useful for applications beyond shares distribution (e.g.
- * load-balance).
- */
-#ifdef CONFIG_FAIR_GROUP_SCHED
         /*
          * CFS Load tracking
          * Under CFS, load is tracked on a per-entity basis and aggregated up.
@@ -284,9 +278,9 @@ struct cfs_rq {
         u64 runnable_load_avg, blocked_load_avg;
         atomic64_t decay_counter, removed_load;
         u64 last_decay;
-#endif /* CONFIG_FAIR_GROUP_SCHED */
-/* These always depend on CONFIG_FAIR_GROUP_SCHED */
+
 #ifdef CONFIG_FAIR_GROUP_SCHED
+        /* Required to track per-cpu representation of a task_group */
         u32 tg_runnable_contrib;
         u64 tg_load_contrib;
 #endif /* CONFIG_FAIR_GROUP_SCHED */
@@ -1027,17 +1021,8 @@ extern void update_group_power(struct sched_domain *sd, int cpu);
 extern void trigger_load_balance(struct rq *rq, int cpu);
 extern void idle_balance(int this_cpu, struct rq *this_rq);
 
-/*
- * Only depends on SMP, FAIR_GROUP_SCHED may be removed when runnable_avg
- * becomes useful in lb
- */
-#if defined(CONFIG_FAIR_GROUP_SCHED)
 extern void idle_enter_fair(struct rq *this_rq);
 extern void idle_exit_fair(struct rq *this_rq);
-#else
-static inline void idle_enter_fair(struct rq *this_rq) {}
-static inline void idle_exit_fair(struct rq *this_rq) {}
-#endif
 
 #else   /* CONFIG_SMP */