From: Peter Zijlstra <[email protected]> Remove the direct {push,pull} balancing operations from switched_{from,to}_dl() / prio_changed_dl() and use the balance callback queue.
Again, err on the side of too many reschedules; since too few is a hard bug while too many is just annoying. Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Thomas Gleixner <[email protected]> Signed-off-by: Byungchul Park <[email protected]> Conflicts: kernel/sched/deadline.c --- kernel/sched/deadline.c | 34 +++++++++++++++++++++------------- 1 file changed, 21 insertions(+), 13 deletions(-) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index ec1f21d..6ab59bb 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -210,16 +210,23 @@ static inline int has_pushable_dl_tasks(struct rq *rq) static int push_dl_task(struct rq *rq); -static DEFINE_PER_CPU(struct callback_head, dl_balance_head); +static DEFINE_PER_CPU(struct callback_head, dl_push_head); +static DEFINE_PER_CPU(struct callback_head, dl_pull_head); static void push_dl_tasks(struct rq *); +static void pull_dl_task(struct rq *); static inline void queue_push_tasks(struct rq *rq) { if (!has_pushable_dl_tasks(rq)) return; - queue_balance_callback(rq, &per_cpu(dl_balance_head, rq->cpu), push_dl_tasks); + queue_balance_callback(rq, &per_cpu(dl_push_head, rq->cpu), push_dl_tasks); +} + +static inline void queue_pull_task(struct rq *rq) +{ + queue_balance_callback(rq, &per_cpu(dl_pull_head, rq->cpu), pull_dl_task); } #else @@ -247,6 +254,10 @@ void dec_dl_migration(struct sched_dl_entity *dl_se, struct dl_rq *dl_rq) static inline void queue_push_tasks(struct rq *rq) { } + +static inline void queue_pull_task(struct rq *rq) +{ +} #endif /* CONFIG_SMP */ static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags); @@ -1541,7 +1552,7 @@ static void switched_from_dl(struct rq *rq, struct task_struct *p) * from an overloaded cpu, if any. */ if (!rq->dl.dl_nr_running) - pull_dl_task(rq); + queue_pull_task(rq); #endif } @@ -1551,8 +1562,6 @@ static void switched_from_dl(struct rq *rq, struct task_struct *p) */ static void switched_to_dl(struct rq *rq, struct task_struct *p) { - int check_resched = 1; - /* * If p is throttled, don't consider the possibility * of preempting rq->curr, the check will be done right @@ -1563,12 +1572,12 @@ static void switched_to_dl(struct rq *rq, struct task_struct *p) if (p->on_rq || rq->curr != p) { #ifdef CONFIG_SMP - if (rq->dl.overloaded && push_dl_task(rq) && rq != task_rq(p)) - /* Only reschedule if pushing failed */ - check_resched = 0; -#endif /* CONFIG_SMP */ - if (check_resched && task_has_dl_policy(rq->curr)) + if (rq->dl.overloaded) + queue_push_tasks(rq); +#else + if (task_has_dl_policy(rq->curr)) check_preempt_curr_dl(rq, p, 0); +#endif /* CONFIG_SMP */ } } @@ -1588,15 +1597,14 @@ static void prio_changed_dl(struct rq *rq, struct task_struct *p, * or lowering its prio, so... */ if (!rq->dl.overloaded) - pull_dl_task(rq); + queue_pull_task(rq); /* * If we now have a earlier deadline task than p, * then reschedule, provided p is still on this * runqueue. */ - if (dl_time_before(rq->dl.earliest_dl.curr, p->dl.deadline) && - rq->curr == p) + if (dl_time_before(rq->dl.earliest_dl.curr, p->dl.deadline)) resched_task(p); #else /* -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
