sched: Maintain per-rq runnable averages

Since runqueues do not have a corresponding sched_entity we instead embed a
sched_avg structure directly.

Signed-off-by: Ben Segall <bsegall@google.com>
Reviewed-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20120823141506.442637130@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 16 insertions, 2 deletions

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 16d67f9b6955..8c5468fcf10d 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1087,8 +1087,14 @@ static inline void update_entity_load_avg(struct sched_entity *se)
         __update_entity_runnable_avg(rq_of(cfs_rq_of(se))->clock_task, &se->avg,
                                      se->on_rq);
 }
+
+static inline void update_rq_runnable_avg(struct rq *rq, int runnable)
+{
+        __update_entity_runnable_avg(rq->clock_task, &rq->avg, runnable);
+}
 #else
 static inline void update_entity_load_avg(struct sched_entity *se) {}
+static inline void update_rq_runnable_avg(struct rq *rq, int runnable) {}
 #endif
 
 static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
@@ -2340,8 +2346,10 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
                 update_cfs_shares(cfs_rq);
         }
 
-        if (!se)
+        if (!se) {
+                update_rq_runnable_avg(rq, rq->nr_running);
                 inc_nr_running(rq);
+        }
         hrtick_update(rq);
 }
 
@@ -2399,8 +2407,10 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags)
                 update_cfs_shares(cfs_rq);
         }
 
-        if (!se)
+        if (!se) {
                 dec_nr_running(rq);
+                update_rq_runnable_avg(rq, 1);
+        }
         hrtick_update(rq);
 }
 
@@ -4586,6 +4596,8 @@ void idle_balance(int this_cpu, struct rq *this_rq)
         if (this_rq->avg_idle < sysctl_sched_migration_cost)
                 return;
 
+        update_rq_runnable_avg(this_rq, 1);
+
         /*
          * Drop the rq->lock, but keep IRQ/preempt disabled.
          */
@@ -5083,6 +5095,8 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued)
                 cfs_rq = cfs_rq_of(se);
                 entity_tick(cfs_rq, se, queued);
         }
+
+        update_rq_runnable_avg(rq, 1);
 }
 
 /*