Every time, we modify load/utilization of sched_entity, we start to sync it with its cfs_rq. This update is done is different ways: -when attaching/detaching a sched_entity, we update cfs_rq and then we sync the entity with the cfs_rq. -when enqueueing/dequeuing the sched_entity, we update both sched_entity and cfs_rq metrics to now.
Use update_load_avg everytime we have to update and sync cfs_rq and sched_entity before changing the state of a sched_enity
Signed-off-by: Vincent Guittot vincent.guittot@linaro.org --- kernel/sched/fair.c | 75 +++++++++++++++++------------------------------------ 1 file changed, 24 insertions(+), 51 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 3d29492..625e7f7 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3088,8 +3088,14 @@ update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq, bool update_freq) return decayed || removed_load; }
+/* + * Optional action to be done while updating the load average + */ +#define UPDATE_TG 0x1 +#define SKIP_AGE_LOAD 0x2 + /* Update task and its cfs_rq load average */ -static inline void update_load_avg(struct sched_entity *se, int update_tg) +static inline void update_load_avg(struct sched_entity *se, int flags) { struct cfs_rq *cfs_rq = cfs_rq_of(se); u64 now = cfs_rq_clock_task(cfs_rq); @@ -3100,11 +3106,12 @@ static inline void update_load_avg(struct sched_entity *se, int update_tg) * Track task load average for carrying it to new CPU after migrated, and * track group sched_entity load average for task_h_load calc in migration */ - __update_load_avg(now, cpu, &se->avg, + if (se->avg.last_update_time && !(flags & SKIP_AGE_LOAD)) + __update_load_avg(now, cpu, &se->avg, se->on_rq * scale_load_down(se->load.weight), cfs_rq->curr == se, NULL);
- if (update_cfs_rq_load_avg(now, cfs_rq, true) && update_tg) + if (update_cfs_rq_load_avg(now, cfs_rq, true) && (flags & UPDATE_TG)) update_tg_load_avg(cfs_rq, 0); }
@@ -3118,26 +3125,6 @@ static inline void update_load_avg(struct sched_entity *se, int update_tg) */ static void attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) { - if (!sched_feat(ATTACH_AGE_LOAD)) - goto skip_aging; - - /* - * If we got migrated (either between CPUs or between cgroups) we'll - * have aged the average right before clearing @last_update_time. - * - * Or we're fresh through post_init_entity_util_avg(). - */ - if (se->avg.last_update_time) { - __update_load_avg(cfs_rq->avg.last_update_time, cpu_of(rq_of(cfs_rq)), - &se->avg, 0, 0, NULL); - - /* - * XXX: we could have just aged the entire load away if we've been - * absent from the fair class for too long. - */ - } - -skip_aging: se->avg.last_update_time = cfs_rq->avg.last_update_time; cfs_rq->avg.load_avg += se->avg.load_avg; cfs_rq->avg.load_sum += se->avg.load_sum; @@ -3157,9 +3144,6 @@ static void attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *s */ static void detach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) { - __update_load_avg(cfs_rq->avg.last_update_time, cpu_of(rq_of(cfs_rq)), - &se->avg, se->on_rq * scale_load_down(se->load.weight), - cfs_rq->curr == se, NULL);
sub_positive(&cfs_rq->avg.load_avg, se->avg.load_avg); sub_positive(&cfs_rq->avg.load_sum, se->avg.load_sum); @@ -3174,34 +3158,20 @@ static inline void enqueue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) { struct sched_avg *sa = &se->avg; - u64 now = cfs_rq_clock_task(cfs_rq); - int migrated, decayed; - - migrated = !sa->last_update_time; - if (!migrated) { - __update_load_avg(now, cpu_of(rq_of(cfs_rq)), sa, - se->on_rq * scale_load_down(se->load.weight), - cfs_rq->curr == se, NULL); - } - - decayed = update_cfs_rq_load_avg(now, cfs_rq, !migrated);
cfs_rq->runnable_load_avg += sa->load_avg; cfs_rq->runnable_load_sum += sa->load_sum;
- if (migrated) + if (!sa->last_update_time) { attach_entity_load_avg(cfs_rq, se); - - if (decayed || migrated) update_tg_load_avg(cfs_rq, 0); + } }
/* Remove the runnable load generated by se from cfs_rq's runnable load average */ static inline void dequeue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) { - update_load_avg(se, 1); - cfs_rq->runnable_load_avg = max_t(long, cfs_rq->runnable_load_avg - se->avg.load_avg, 0); cfs_rq->runnable_load_sum = @@ -3275,7 +3245,10 @@ update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq, bool update_freq) return 0; }
-static inline void update_load_avg(struct sched_entity *se, int not_used) +#define UPDATE_TG 0x0 +#define SKIP_AGE_LOAD 0x0 + +static inline void update_load_avg(struct sched_entity *se, int not_used1) { struct cfs_rq *cfs_rq = cfs_rq_of(se); struct rq *rq = rq_of(cfs_rq); @@ -3423,6 +3396,7 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) if (renorm && !curr) se->vruntime += cfs_rq->min_vruntime;
+ update_load_avg(se, UPDATE_TG); enqueue_entity_load_avg(cfs_rq, se); account_entity_enqueue(cfs_rq, se); update_cfs_shares(cfs_rq); @@ -3497,6 +3471,7 @@ 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_load_avg(se, UPDATE_TG); dequeue_entity_load_avg(cfs_rq, se);
update_stats_dequeue(cfs_rq, se, flags); @@ -3575,7 +3550,7 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) */ update_stats_wait_end(cfs_rq, se); __dequeue_entity(cfs_rq, se); - update_load_avg(se, 1); + update_load_avg(se, UPDATE_TG); }
update_stats_curr_start(cfs_rq, se); @@ -3693,7 +3668,7 @@ entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr, int queued) /* * Ensure that runnable average is periodically updated. */ - update_load_avg(curr, 1); + update_load_avg(curr, UPDATE_TG); update_cfs_shares(cfs_rq);
#ifdef CONFIG_SCHED_HRTICK @@ -4582,7 +4557,7 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags) if (cfs_rq_throttled(cfs_rq)) break;
- update_load_avg(se, 1); + update_load_avg(se, UPDATE_TG); update_cfs_shares(cfs_rq); }
@@ -4641,7 +4616,7 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags) if (cfs_rq_throttled(cfs_rq)) break;
- update_load_avg(se, 1); + update_load_avg(se, UPDATE_TG); update_cfs_shares(cfs_rq); }
@@ -8520,7 +8495,6 @@ 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)) { /* @@ -8532,7 +8506,7 @@ static void detach_task_cfs_rq(struct task_struct *p) }
/* Catch up with the cfs_rq and remove our load when we leave */ - update_cfs_rq_load_avg(now, cfs_rq, false); + update_load_avg(se, 0); detach_entity_load_avg(cfs_rq, se); update_tg_load_avg(cfs_rq, false); } @@ -8540,7 +8514,6 @@ static void detach_task_cfs_rq(struct task_struct *p) static void attach_entity_cfs_rq(struct sched_entity *se) { struct cfs_rq *cfs_rq = cfs_rq_of(se); - u64 now = cfs_rq_clock_task(cfs_rq);
#ifdef CONFIG_FAIR_GROUP_SCHED /* @@ -8551,7 +8524,7 @@ static void attach_entity_cfs_rq(struct sched_entity *se) #endif
/* Synchronize task with its cfs_rq */ - update_cfs_rq_load_avg(now, cfs_rq, false); + update_load_avg(se, sched_feat(ATTACH_AGE_LOAD) ? 0 : SKIP_AGE_LOAD); attach_entity_load_avg(cfs_rq, se); update_tg_load_avg(cfs_rq, false); }