sched: Put rq's sched_avg under CONFIG_FAIR_GROUP_SCHED

The struct sched_avg of struct rq is only used in case group
scheduling is enabled inside __update_tg_runnable_avg() to update
per-cpu representation of a task group.  I.e. that there is no need to
maintain the runnable avg of a rq in the !CONFIG_FAIR_GROUP_SCHED case.

This patch guards struct sched_avg of struct rq and
update_rq_runnable_avg() with CONFIG_FAIR_GROUP_SCHED.

There is an extra empty definition for update_rq_runnable_avg()
necessary for the !CONFIG_FAIR_GROUP_SCHED && CONFIG_SMP case.

The function print_cfs_group_stats() which prints out struct sched_avg
of struct rq is already guarded with CONFIG_FAIR_GROUP_SCHED.

Reviewed-by: Ben Segall <bsegall@google.com>
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/530DCDC5.1060406@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

2 files changed, 9 insertions, 8 deletions

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index a3a41c61a2c9..be4f7d9eaf03 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2374,12 +2374,19 @@ static inline void __update_group_entity_contrib(struct sched_entity *se)
                 se->avg.load_avg_contrib >>= NICE_0_SHIFT;
         }
 }
+
+static inline void update_rq_runnable_avg(struct rq *rq, int runnable)
+{
+        __update_entity_runnable_avg(rq_clock_task(rq), &rq->avg, runnable);
+        __update_tg_runnable_avg(&rq->avg, &rq->cfs);
+}
 #else /* CONFIG_FAIR_GROUP_SCHED */
 static inline void __update_cfs_rq_tg_load_contrib(struct cfs_rq *cfs_rq,
                                                  int force_update) {}
 static inline void __update_tg_runnable_avg(struct sched_avg *sa,
                                                   struct cfs_rq *cfs_rq) {}
 static inline void __update_group_entity_contrib(struct sched_entity *se) {}
+static inline void update_rq_runnable_avg(struct rq *rq, int runnable) {}
 #endif /* CONFIG_FAIR_GROUP_SCHED */
 
 static inline void __update_task_entity_contrib(struct sched_entity *se)
@@ -2478,12 +2485,6 @@ static void update_cfs_rq_blocked_load(struct cfs_rq *cfs_rq, int force_update)
         __update_cfs_rq_tg_load_contrib(cfs_rq, force_update);
 }
 
-static inline void update_rq_runnable_avg(struct rq *rq, int runnable)
-{
-        __update_entity_runnable_avg(rq_clock_task(rq), &rq->avg, runnable);
-        __update_tg_runnable_avg(&rq->avg, &rq->cfs);
-}
-
 /* Add the load generated by se into cfs_rq's child load-average */
 static inline void enqueue_entity_load_avg(struct cfs_rq *cfs_rq,
                                                   struct sched_entity *se,
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index d608125b36ef..046084ebb1fb 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -541,6 +541,8 @@ struct rq {
 #ifdef CONFIG_FAIR_GROUP_SCHED
         /* list of leaf cfs_rq on this cpu: */
         struct list_head leaf_cfs_rq_list;
+
+        struct sched_avg avg;
 #endif /* CONFIG_FAIR_GROUP_SCHED */
 
         /*
@@ -630,8 +632,6 @@ struct rq {
 #ifdef CONFIG_SMP
         struct llist_head wake_list;
 #endif
-
-        struct sched_avg avg;
 };
 
 static inline int cpu_of(struct rq *rq)