[PATCH 1/6 v6] sched: factorize attach/detach entity

From: Vincent Guittot
Date: Tue Nov 08 2016 - 03:26:32 EST


Factorize post_init_entity_util_avg and part of attach_task_cfs_rq
in one function attach_entity_cfs_rq.
Create symmetric detach_entity_cfs_rq function

Signed-off-by: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
---
kernel/sched/fair.c | 54 +++++++++++++++++++++++++++++++----------------------
1 file changed, 32 insertions(+), 22 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index c242944..6dd9ea9 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -708,9 +708,7 @@ void init_entity_runnable_average(struct sched_entity *se)
}

static inline u64 cfs_rq_clock_task(struct cfs_rq *cfs_rq);
-static int update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq, bool update_freq);
-static void update_tg_load_avg(struct cfs_rq *cfs_rq, int force);
-static void attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se);
+static void attach_entity_cfs_rq(struct sched_entity *se);

/*
* With new tasks being created, their initial util_avgs are extrapolated
@@ -742,7 +740,6 @@ void post_init_entity_util_avg(struct sched_entity *se)
struct cfs_rq *cfs_rq = cfs_rq_of(se);
struct sched_avg *sa = &se->avg;
long cap = (long)(SCHED_CAPACITY_SCALE - cfs_rq->avg.util_avg) / 2;
- u64 now = cfs_rq_clock_task(cfs_rq);

if (cap > 0) {
if (cfs_rq->avg.util_avg != 0) {
@@ -770,14 +767,12 @@ void post_init_entity_util_avg(struct sched_entity *se)
* such that the next switched_to_fair() has the
* expected state.
*/
- se->avg.last_update_time = now;
+ se->avg.last_update_time = cfs_rq_clock_task(cfs_rq);
return;
}
}

- update_cfs_rq_load_avg(now, cfs_rq, false);
- attach_entity_load_avg(cfs_rq, se);
- update_tg_load_avg(cfs_rq, false);
+ attach_entity_cfs_rq(se);
}

#else /* !CONFIG_SMP */
@@ -8687,30 +8682,19 @@ static inline bool vruntime_normalized(struct task_struct *p)
return false;
}

-static void detach_task_cfs_rq(struct task_struct *p)
+static void detach_entity_cfs_rq(struct sched_entity *se)
{
- struct sched_entity *se = &p->se;
struct cfs_rq *cfs_rq = cfs_rq_of(se);
u64 now = cfs_rq_clock_task(cfs_rq);

- if (!vruntime_normalized(p)) {
- /*
- * Fix up our vruntime so that the current sleep doesn't
- * cause 'unlimited' sleep bonus.
- */
- place_entity(cfs_rq, se, 0);
- se->vruntime -= cfs_rq->min_vruntime;
- }
-
/* Catch up with the cfs_rq and remove our load when we leave */
update_cfs_rq_load_avg(now, cfs_rq, false);
detach_entity_load_avg(cfs_rq, se);
update_tg_load_avg(cfs_rq, false);
}

-static void attach_task_cfs_rq(struct task_struct *p)
+static void attach_entity_cfs_rq(struct sched_entity *se)
{
- struct sched_entity *se = &p->se;
struct cfs_rq *cfs_rq = cfs_rq_of(se);
u64 now = cfs_rq_clock_task(cfs_rq);

@@ -8722,10 +8706,36 @@ static void attach_task_cfs_rq(struct task_struct *p)
se->depth = se->parent ? se->parent->depth + 1 : 0;
#endif

- /* Synchronize task with its cfs_rq */
+ /* Synchronize entity with its cfs_rq */
update_cfs_rq_load_avg(now, cfs_rq, false);
attach_entity_load_avg(cfs_rq, se);
update_tg_load_avg(cfs_rq, false);
+}
+
+static void detach_task_cfs_rq(struct task_struct *p)
+{
+ struct sched_entity *se = &p->se;
+ struct cfs_rq *cfs_rq = cfs_rq_of(se);
+ u64 now = cfs_rq_clock_task(cfs_rq);
+
+ if (!vruntime_normalized(p)) {
+ /*
+ * Fix up our vruntime so that the current sleep doesn't
+ * cause 'unlimited' sleep bonus.
+ */
+ place_entity(cfs_rq, se, 0);
+ se->vruntime -= cfs_rq->min_vruntime;
+ }
+
+ detach_entity_cfs_rq(se);
+}
+
+static void attach_task_cfs_rq(struct task_struct *p)
+{
+ struct sched_entity *se = &p->se;
+ struct cfs_rq *cfs_rq = cfs_rq_of(se);
+
+ attach_entity_cfs_rq(se);

if (!vruntime_normalized(p))
se->vruntime += cfs_rq->min_vruntime;
--
2.7.4