sched/pelt: Cleanup PELT divider

Factorize in a single place the calculation of the divider to be used to
to compute *_avg from *_sum value

Suggested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200612154703.23555-1-vincent.guittot@linaro.org

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 295c9ffa850b3e28aab034ae2ee26b700ca53ecb..0424a0af5f87bb4378e9d15534b7bcc6bbca9f3d 100644 (file)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3094,7 +3094,7 @@ static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se,
 
 #ifdef CONFIG_SMP
        do {
-               u32 divider = LOAD_AVG_MAX - 1024 + se->avg.period_contrib;
+               u32 divider = get_pelt_divider(&se->avg);
 
                se->avg.load_avg = div_u64(se_weight(se) * se->avg.load_sum, divider);
        } while (0);
@@ -3440,16 +3440,18 @@ static inline void
 update_tg_cfs_util(struct cfs_rq *cfs_rq, struct sched_entity *se, struct cfs_rq *gcfs_rq)
 {
        long delta = gcfs_rq->avg.util_avg - se->avg.util_avg;
-       /*
-        * cfs_rq->avg.period_contrib can be used for both cfs_rq and se.
-        * See ___update_load_avg() for details.
-        */
-       u32 divider = LOAD_AVG_MAX - 1024 + cfs_rq->avg.period_contrib;
+       u32 divider;
 
        /* Nothing to update */
        if (!delta)
                return;
 
+       /*
+        * cfs_rq->avg.period_contrib can be used for both cfs_rq and se.
+        * See ___update_load_avg() for details.
+        */
+       divider = get_pelt_divider(&cfs_rq->avg);
+
        /* Set new sched_entity's utilization */
        se->avg.util_avg = gcfs_rq->avg.util_avg;
        se->avg.util_sum = se->avg.util_avg * divider;
@@ -3463,16 +3465,18 @@ static inline void
 update_tg_cfs_runnable(struct cfs_rq *cfs_rq, struct sched_entity *se, struct cfs_rq *gcfs_rq)
 {
        long delta = gcfs_rq->avg.runnable_avg - se->avg.runnable_avg;
-       /*
-        * cfs_rq->avg.period_contrib can be used for both cfs_rq and se.
-        * See ___update_load_avg() for details.
-        */
-       u32 divider = LOAD_AVG_MAX - 1024 + cfs_rq->avg.period_contrib;
+       u32 divider;
 
        /* Nothing to update */
        if (!delta)
                return;
 
+       /*
+        * cfs_rq->avg.period_contrib can be used for both cfs_rq and se.
+        * See ___update_load_avg() for details.
+        */
+       divider = get_pelt_divider(&cfs_rq->avg);
+
        /* Set new sched_entity's runnable */
        se->avg.runnable_avg = gcfs_rq->avg.runnable_avg;
        se->avg.runnable_sum = se->avg.runnable_avg * divider;
@@ -3500,7 +3504,7 @@ update_tg_cfs_load(struct cfs_rq *cfs_rq, struct sched_entity *se, struct cfs_rq
         * cfs_rq->avg.period_contrib can be used for both cfs_rq and se.
         * See ___update_load_avg() for details.
         */
-       divider = LOAD_AVG_MAX - 1024 + cfs_rq->avg.period_contrib;
+       divider = get_pelt_divider(&cfs_rq->avg);
 
        if (runnable_sum >= 0) {
                /*
@@ -3646,7 +3650,7 @@ update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq)
 
        if (cfs_rq->removed.nr) {
                unsigned long r;
-               u32 divider = LOAD_AVG_MAX - 1024 + sa->period_contrib;
+               u32 divider = get_pelt_divider(&cfs_rq->avg);
 
                raw_spin_lock(&cfs_rq->removed.lock);
                swap(cfs_rq->removed.util_avg, removed_util);
@@ -3701,7 +3705,7 @@ static void attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *s
         * cfs_rq->avg.period_contrib can be used for both cfs_rq and se.
         * See ___update_load_avg() for details.
         */
-       u32 divider = LOAD_AVG_MAX - 1024 + cfs_rq->avg.period_contrib;
+       u32 divider = get_pelt_divider(&cfs_rq->avg);
 
        /*
         * When we attach the @se to the @cfs_rq, we must align the decay

diff --git a/kernel/sched/pelt.c b/kernel/sched/pelt.c
index dea5567e4f727f3ef0f5599d41bda672b234f6bf..11bea3b08115b50a7fb1a09313afd031da8b7f77 100644 (file)
--- a/kernel/sched/pelt.c
+++ b/kernel/sched/pelt.c
@@ -262,7 +262,7 @@ ___update_load_sum(u64 now, struct sched_avg *sa,
 static __always_inline void
 ___update_load_avg(struct sched_avg *sa, unsigned long load)
 {
-       u32 divider = LOAD_AVG_MAX - 1024 + sa->period_contrib;
+       u32 divider = get_pelt_divider(sa);
 
        /*
         * Step 2: update *_avg.

diff --git a/kernel/sched/pelt.h b/kernel/sched/pelt.h
index eb034d9f024da54a5caf32807822c5f9721ba6b0..795e43e02afc6f353a2cff6d298fd15711bcf732 100644 (file)
--- a/kernel/sched/pelt.h
+++ b/kernel/sched/pelt.h
@@ -37,6 +37,11 @@ update_irq_load_avg(struct rq *rq, u64 running)
 }
 #endif
 
+static inline u32 get_pelt_divider(struct sched_avg *avg)
+{
+       return LOAD_AVG_MAX - 1024 + avg->period_contrib;
+}
+
 /*
  * When a task is dequeued, its estimated utilization should not be update if
  * its util_avg has not been updated at least once.