sched: Aggregate total task_group load

Maintain a global running sum of the average load seen on each cfs_rq belonging
to each task group so that it may be used in calculating an appropriate
shares:weight distribution.

Signed-off-by: Paul Turner <pjt@google.com>
Reviewed-by: Ben Segall <bsegall@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20120823141506.792901086@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 22 insertions, 0 deletions

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 74dc29ba1ad1..db788222f198 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1102,6 +1102,26 @@ static inline u64 __synchronize_entity_decay(struct sched_entity *se)
         return decays;
 }
 
+#ifdef CONFIG_FAIR_GROUP_SCHED
+static inline void __update_cfs_rq_tg_load_contrib(struct cfs_rq *cfs_rq,
+                                                 int force_update)
+{
+        struct task_group *tg = cfs_rq->tg;
+        s64 tg_contrib;
+
+        tg_contrib = cfs_rq->runnable_load_avg + cfs_rq->blocked_load_avg;
+        tg_contrib -= cfs_rq->tg_load_contrib;
+
+        if (force_update || abs64(tg_contrib) > cfs_rq->tg_load_contrib / 8) {
+                atomic64_add(tg_contrib, &tg->load_avg);
+                cfs_rq->tg_load_contrib += tg_contrib;
+        }
+}
+#else
+static inline void __update_cfs_rq_tg_load_contrib(struct cfs_rq *cfs_rq,
+                                                 int force_update) {}
+#endif
+
 /* Compute the current contribution to load_avg by se, return any delta */
 static long __update_entity_load_avg_contrib(struct sched_entity *se)
 {
@@ -1172,6 +1192,8 @@ static void update_cfs_rq_blocked_load(struct cfs_rq *cfs_rq, int force_update)
                 atomic64_add(decays, &cfs_rq->decay_counter);
                 cfs_rq->last_decay = now;
         }
+
+        __update_cfs_rq_tg_load_contrib(cfs_rq, force_update);
 }
 
 static inline void update_rq_runnable_avg(struct rq *rq, int runnable)