This is missing the below #ifdef guards, adding here has a note for
the next resping on list.
On 22-Feb 17:01, Patrick Bellasi wrote:
[...]
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index e1febd252a84..c8526687f107 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -5205,6 +5205,23 @@ static inline void hrtick_update(struct rq *rq)
> }
> #endif
>
#ifdef CONFIG_SMP
> +static inline unsigned long task_util(struct task_struct *p);
> +static inline unsigned long _task_util_est(struct task_struct *p);
> +
> +static inline void util_est_enqueue(struct cfs_rq *cfs_rq,
> + struct task_struct *p)
> +{
> + unsigned int enqueued;
> +
> + if (!sched_feat(UTIL_EST))
> + return;
> +
> + /* Update root cfs_rq's estimated utilization */
> + enqueued = READ_ONCE(cfs_rq->avg.util_est.enqueued);
> + enqueued += _task_util_est(p);
> + WRITE_ONCE(cfs_rq->avg.util_est.enqueued, enqueued);
> +}
> +
#else
static inline void util_est_enqueue(struct cfs_rq *cfs_rq
struct task_struct *p)
{
}
#endif /* CONFIG_SMP */
> /*
> * The enqueue_task method is called before nr_running is
> * increased. Here we update the fair scheduling stats and
> @@ -5257,9 +5274,86 @@ enqueue_task_fair(struct rq *rq, struct task_struct
> *p, int flags)
> if (!se)
> add_nr_running(rq, 1);
>
> + util_est_enqueue(&rq->cfs, p);
> hrtick_update(rq);
> }
>
> +/*
> + * Check if a (signed) value is within a specified (unsigned) margin,
> + * based on the observation that:
> + * abs(x) < y := (unsigned)(x + y - 1) < (2 * y - 1)
> + *
> + * NOTE: this only works when value + maring < INT_MAX.
> + */
> +static inline bool within_margin(int value, int margin)
> +{
> + return ((unsigned int)(value + margin - 1) < (2 * margin - 1));
> +}
> +
> +static inline void util_est_dequeue(struct cfs_rq *cfs_rq,
> + struct task_struct *p,
> + bool task_sleep)
> +{
#ifdef CONFIG_SMP
> + long last_ewma_diff;
> + struct util_est ue;
> +
> + if (!sched_feat(UTIL_EST))
> + return;
> +
> + /*
> + * Update root cfs_rq's estimated utilization
> + *
> + * If *p is the last task then the root cfs_rq's estimated utilization
> + * of a CPU is 0 by definition.
> + */
> + ue.enqueued = 0;
> + if (cfs_rq->nr_running) {
> + ue.enqueued = READ_ONCE(cfs_rq->avg.util_est.enqueued);
> + ue.enqueued -= min_t(unsigned int, ue.enqueued,
> + _task_util_est(p));
> + }
> + WRITE_ONCE(cfs_rq->avg.util_est.enqueued, ue.enqueued);
> +
> + /*
> + * Skip update of task's estimated utilization when the task has not
> + * yet completed an activation, e.g. being migrated.
> + */
> + if (!task_sleep)
> + return;
> +
> + /*
> + * Skip update of task's estimated utilization when its EWMA is
> + * already ~1% close to its last activation value.
> + */
> + ue = READ_ONCE(p->se.avg.util_est);
> + ue.enqueued = task_util(p);
> + last_ewma_diff = ue.enqueued - ue.ewma;
> + if (within_margin(last_ewma_diff, (SCHED_CAPACITY_SCALE / 100)))
> + return;
> +
> + /*
> + * Update Task's estimated utilization
> + *
> + * When *p completes an activation we can consolidate another sample
> + * of the task size. This is done by storing the current PELT value
> + * as ue.enqueued and by using this value to update the Exponential
> + * Weighted Moving Average (EWMA):
> + *
> + * ewma(t) = w * task_util(p) + (1-w) * ewma(t-1)
> + * = w * task_util(p) + ewma(t-1) - w * ewma(t-1)
> + * = w * (task_util(p) - ewma(t-1)) + ewma(t-1)
> + * = w * ( last_ewma_diff ) + ewma(t-1)
> + * = w * (last_ewma_diff + ewma(t-1) / w)
> + *
> + * Where 'w' is the weight of new samples, which is configured to be
> + * 0.25, thus making w=1/4 ( >>= UTIL_EST_WEIGHT_SHIFT)
> + */
> + ue.ewma <<= UTIL_EST_WEIGHT_SHIFT;
> + ue.ewma += last_ewma_diff;
> + ue.ewma >>= UTIL_EST_WEIGHT_SHIFT;
> + WRITE_ONCE(p->se.avg.util_est, ue);
#endif /* CONFIG_SMP */
> +}
> +
> static void set_next_buddy(struct sched_entity *se);
>
> /*
> @@ -5316,6 +5410,7 @@ static void dequeue_task_fair(struct rq *rq, struct
> task_struct *p, int flags)
> if (!se)
> sub_nr_running(rq, 1);
>
> + util_est_dequeue(&rq->cfs, p, task_sleep);
> hrtick_update(rq);
> }
>
--
#include <best/regards.h>
Patrick Bellasi
