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authorPaul Turner <pjt@google.com>2012-10-04 13:18:30 +0200
committerIngo Molnar <mingo@kernel.org>2012-10-24 10:27:21 +0200
commit2dac754e10a5d41d94d2d2365c0345d4f215a266 (patch)
tree4016ab214b5b51b2be5c40ab2fdc9832c8aca870 /kernel/sched/fair.c
parent18bf2805d9b30cb823d4919b42cd230f59c7ce1f (diff)
downloadlinaro-lsk-2dac754e10a5d41d94d2d2365c0345d4f215a266.tar.gz
sched: Aggregate load contributed by task entities on parenting cfs_rq
For a given task t, we can compute its contribution to load as: task_load(t) = runnable_avg(t) * weight(t) On a parenting cfs_rq we can then aggregate: runnable_load(cfs_rq) = \Sum task_load(t), for all runnable children t Maintain this bottom up, with task entities adding their contributed load to the parenting cfs_rq sum. When a task entity's load changes we add the same delta to the maintained sum. 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/20120823141506.514678907@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched/fair.c')
-rw-r--r--kernel/sched/fair.c51
1 files changed, 47 insertions, 4 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 8c5468fcf10..77af759e567 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1081,20 +1081,63 @@ static __always_inline int __update_entity_runnable_avg(u64 now,
return decayed;
}
+/* 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);
+
+ return se->avg.load_avg_contrib - old_contrib;
+}
+
/* Update a sched_entity's runnable average */
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);
+ struct cfs_rq *cfs_rq = cfs_rq_of(se);
+ long contrib_delta;
+
+ if (!__update_entity_runnable_avg(rq_of(cfs_rq)->clock_task, &se->avg,
+ se->on_rq))
+ return;
+
+ contrib_delta = __update_entity_load_avg_contrib(se);
+ if (se->on_rq)
+ cfs_rq->runnable_load_avg += contrib_delta;
}
static inline void update_rq_runnable_avg(struct rq *rq, int runnable)
{
__update_entity_runnable_avg(rq->clock_task, &rq->avg, runnable);
}
+
+/* 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)
+{
+ update_entity_load_avg(se);
+ cfs_rq->runnable_load_avg += se->avg.load_avg_contrib;
+}
+
+/* Remove se's load from this cfs_rq child load-average */
+static inline void dequeue_entity_load_avg(struct cfs_rq *cfs_rq,
+ struct sched_entity *se)
+{
+ update_entity_load_avg(se);
+ cfs_rq->runnable_load_avg -= se->avg.load_avg_contrib;
+}
#else
static inline void update_entity_load_avg(struct sched_entity *se) {}
static inline void update_rq_runnable_avg(struct rq *rq, int runnable) {}
+static inline void enqueue_entity_load_avg(struct cfs_rq *cfs_rq,
+ struct sched_entity *se) {}
+static inline void dequeue_entity_load_avg(struct cfs_rq *cfs_rq,
+ struct sched_entity *se) {}
#endif
static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
@@ -1223,7 +1266,7 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
*/
update_curr(cfs_rq);
update_cfs_load(cfs_rq, 0);
- update_entity_load_avg(se);
+ enqueue_entity_load_avg(cfs_rq, se);
account_entity_enqueue(cfs_rq, se);
update_cfs_shares(cfs_rq);
@@ -1298,7 +1341,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
* Update run-time statistics of the 'current'.
*/
update_curr(cfs_rq);
- update_entity_load_avg(se);
+ dequeue_entity_load_avg(cfs_rq, se);
update_stats_dequeue(cfs_rq, se);
if (flags & DEQUEUE_SLEEP) {