sched: Compute load contribution by a group entity
Unlike task entities who have a fixed weight, group entities instead own a
fraction of their parenting task_group's shares as their contributed weight.
Compute this fraction so that we can correctly account hierarchies and shared
entity nodes.
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/20120823141506.855074415@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index db78822..e20cb26 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1117,22 +1117,43 @@
cfs_rq->tg_load_contrib += tg_contrib;
}
}
+
+static inline void __update_group_entity_contrib(struct sched_entity *se)
+{
+ struct cfs_rq *cfs_rq = group_cfs_rq(se);
+ struct task_group *tg = cfs_rq->tg;
+ u64 contrib;
+
+ contrib = cfs_rq->tg_load_contrib * tg->shares;
+ se->avg.load_avg_contrib = div64_u64(contrib,
+ atomic64_read(&tg->load_avg) + 1);
+}
#else
static inline void __update_cfs_rq_tg_load_contrib(struct cfs_rq *cfs_rq,
int force_update) {}
+static inline void __update_group_entity_contrib(struct sched_entity *se) {}
#endif
+static inline void __update_task_entity_contrib(struct sched_entity *se)
+{
+ u32 contrib;
+
+ /* avoid overflowing a 32-bit type w/ SCHED_LOAD_SCALE */
+ contrib = se->avg.runnable_avg_sum * scale_load_down(se->load.weight);
+ contrib /= (se->avg.runnable_avg_period + 1);
+ se->avg.load_avg_contrib = scale_load(contrib);
+}
+
/* Compute the current contribution to load_avg by se, return any delta */
static long __update_entity_load_avg_contrib(struct sched_entity *se)
{
long old_contrib = se->avg.load_avg_contrib;
- if (!entity_is_task(se))
- return 0;
-
- se->avg.load_avg_contrib = div64_u64(se->avg.runnable_avg_sum *
- se->load.weight,
- se->avg.runnable_avg_period + 1);
+ if (entity_is_task(se)) {
+ __update_task_entity_contrib(se);
+ } else {
+ __update_group_entity_contrib(se);
+ }
return se->avg.load_avg_contrib - old_contrib;
}