Hi,
On Thu, Aug 13, 2015 at 07:49:19PM +0900, byungchul.p...@lge.com wrote:
> +static inline int need_vruntime_adjust(struct task_struct *p, int queued)
> +{
> + struct sched_entity *se = &p->se;
> +
> + /*
> + * When !queued, vruntime of the task has usually NOT been normalized.
> + * But there are some cases where it has already been normalized:
> + *
> + * - Moving a forked child which is waiting for being woken up by
> + * wake_up_new_task().
> + * - Moving a task which has been woken up by try_to_wake_up() and
> + * waiting for actually being woken up by sched_ttwu_pending().
> + */
> + if (queued)
> + return 0;
> +
> + if (!se->sum_exec_runtime || p->state == TASK_WAKING)
> + return 0;
> +
> + if (p->state != TASK_RUNNING)
> + return 1;
> +
> + return 0;
> +}
Original switched_from/to_fair() do not include the following check.
if (!se->sum_exec_runtime || p->state == TASK_WAKING)
return 0;
I guess you're sure this check will always fail in switched_from/to_fair() case
Thanks
> static void switched_from_fair(struct rq *rq, struct task_struct *p)
> {
> struct sched_entity *se = &p->se;
> @@ -7918,7 +7943,7 @@ static void switched_from_fair(struct rq *rq, struct
> task_struct *p)
> * have normalized the vruntime, if it's !queued, then only when
> * the task is sleeping will it still have non-normalized vruntime.
> */
> - if (!task_on_rq_queued(p) && p->state != TASK_RUNNING) {
> + if (need_vruntime_adjust(p, task_on_rq_queued(p))) {
> /*
> * Fix up our vruntime so that the current sleep doesn't
> * cause 'unlimited' sleep bonus.
> @@ -7939,7 +7964,6 @@ static void switched_from_fair(struct rq *rq, struct
> task_struct *p)
> static void switched_to_fair(struct rq *rq, struct task_struct *p)
> {
> struct sched_entity *se = &p->se;
> -
> #ifdef CONFIG_FAIR_GROUP_SCHED
> /*
> * Since the real-depth could have been changed (only FAIR
> @@ -7964,7 +7988,7 @@ static void switched_to_fair(struct rq *rq, struct
> task_struct *p)
> * has non-normalized vruntime, if it's !queued, then it still
> has
> * normalized vruntime.
> */
> - if (p->state != TASK_RUNNING)
> + if (need_vruntime_adjust(p, task_on_rq_queued(p)))
> se->vruntime += cfs_rq_of(se)->min_vruntime;
> return;
> }
> @@ -8014,55 +8038,9 @@ void init_cfs_rq(struct cfs_rq *cfs_rq)
> #ifdef CONFIG_FAIR_GROUP_SCHED
> static void task_move_group_fair(struct task_struct *p, int queued)
> {
> - struct sched_entity *se = &p->se;
> - struct cfs_rq *cfs_rq;
> -
> - /*
> - * If the task was not on the rq at the time of this cgroup movement
> - * it must have been asleep, sleeping tasks keep their ->vruntime
> - * absolute on their old rq until wakeup (needed for the fair sleeper
> - * bonus in place_entity()).
> - *
> - * If it was on the rq, we've just 'preempted' it, which does convert
> - * ->vruntime to a relative base.
> - *
> - * Make sure both cases convert their relative position when migrating
> - * to another cgroup's rq. This does somewhat interfere with the
> - * fair sleeper stuff for the first placement, but who cares.
> - */
> - /*
> - * When !queued, vruntime of the task has usually NOT been normalized.
> - * But there are some cases where it has already been normalized:
> - *
> - * - Moving a forked child which is waiting for being woken up by
> - * wake_up_new_task().
> - * - Moving a task which has been woken up by try_to_wake_up() and
> - * waiting for actually being woken up by sched_ttwu_pending().
> - *
> - * To prevent boost or penalty in the new cfs_rq caused by delta
> - * min_vruntime between the two cfs_rqs, we skip vruntime adjustment.
> - */
> - if (!queued && (!se->sum_exec_runtime || p->state == TASK_WAKING))
> - queued = 1;
> -
> - cfs_rq = cfs_rq_of(se);
> - if (!queued)
> - se->vruntime -= cfs_rq->min_vruntime;
> -
> -#ifdef CONFIG_SMP
> - /* synchronize task with its prev cfs_rq */
> - detach_entity_load_avg(cfs_rq, se);
> -#endif
> + switched_from_fair(task_rq(p), p);
> set_task_rq(p, task_cpu(p));
> - se->depth = se->parent ? se->parent->depth + 1 : 0;
> - cfs_rq = cfs_rq_of(se);
> - if (!queued)
> - se->vruntime += cfs_rq->min_vruntime;
> -
> -#ifdef CONFIG_SMP
> - /* Virtually synchronize task with its new cfs_rq */
> - attach_entity_load_avg(cfs_rq, se);
> -#endif
> + switched_to_fair(task_rq(p), p);
> }
>
> void free_fair_sched_group(struct task_group *tg)
--
Tao
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