diff options
| -rw-r--r-- | include/linux/sched.h | 2 | ||||
| -rw-r--r-- | kernel/sched.c | 47 | ||||
| -rw-r--r-- | kernel/sched_fair.c | 28 |
3 files changed, 34 insertions, 43 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index ca72ed42ac3..31d9dec7867 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1102,7 +1102,7 @@ struct sched_class { void (*set_curr_task) (struct rq *rq); void (*task_tick) (struct rq *rq, struct task_struct *p, int queued); - void (*task_new) (struct rq *rq, struct task_struct *p); + void (*task_fork) (struct task_struct *p); void (*switched_from) (struct rq *this_rq, struct task_struct *task, int running); diff --git a/kernel/sched.c b/kernel/sched.c index c92670f8e09..33c90357313 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -1811,6 +1811,20 @@ static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares) static void calc_load_account_active(struct rq *this_rq); +static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) +{ + set_task_rq(p, cpu); +#ifdef CONFIG_SMP + /* + * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be + * successfuly executed on another CPU. We must ensure that updates of + * per-task data have been completed by this moment. + */ + smp_wmb(); + task_thread_info(p)->cpu = cpu; +#endif +} + #include "sched_stats.h" #include "sched_idletask.c" #include "sched_fair.c" @@ -1967,20 +1981,6 @@ inline int task_curr(const struct task_struct *p) return cpu_curr(task_cpu(p)) == p; } -static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) -{ - set_task_rq(p, cpu); -#ifdef CONFIG_SMP - /* - * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be - * successfuly executed on another CPU. We must ensure that updates of - * per-task data have been completed by this moment. - */ - smp_wmb(); - task_thread_info(p)->cpu = cpu; -#endif -} - static inline void check_class_changed(struct rq *rq, struct task_struct *p, const struct sched_class *prev_class, int oldprio, int running) @@ -2552,7 +2552,6 @@ static void __sched_fork(struct task_struct *p) void sched_fork(struct task_struct *p, int clone_flags) { int cpu = get_cpu(); - unsigned long flags; __sched_fork(p); @@ -2586,13 +2585,13 @@ void sched_fork(struct task_struct *p, int clone_flags) if (!rt_prio(p->prio)) p->sched_class = &fair_sched_class; + if (p->sched_class->task_fork) + p->sched_class->task_fork(p); + #ifdef CONFIG_SMP cpu = select_task_rq(p, SD_BALANCE_FORK, 0); #endif - local_irq_save(flags); - update_rq_clock(cpu_rq(cpu)); set_task_cpu(p, cpu); - local_irq_restore(flags); #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) if (likely(sched_info_on())) @@ -2625,17 +2624,7 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags) rq = task_rq_lock(p, &flags); BUG_ON(p->state != TASK_RUNNING); update_rq_clock(rq); - - if (!p->sched_class->task_new || !current->se.on_rq) { - activate_task(rq, p, 0); - } else { - /* - * Let the scheduling class do new task startup - * management (if any): - */ - p->sched_class->task_new(rq, p); - inc_nr_running(rq); - } + activate_task(rq, p, 0); trace_sched_wakeup_new(rq, p, 1); check_preempt_curr(rq, p, WF_FORK); #ifdef CONFIG_SMP diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 613c1c74967..44ec80ccfa8 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1922,28 +1922,30 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued) } /* - * Share the fairness runtime between parent and child, thus the - * total amount of pressure for CPU stays equal - new tasks - * get a chance to run but frequent forkers are not allowed to - * monopolize the CPU. Note: the parent runqueue is locked, - * the child is not running yet. + * called on fork with the child task as argument from the parent's context + * - child not yet on the tasklist + * - preemption disabled */ -static void task_new_fair(struct rq *rq, struct task_struct *p) +static void task_fork_fair(struct task_struct *p) { - struct cfs_rq *cfs_rq = task_cfs_rq(p); + struct cfs_rq *cfs_rq = task_cfs_rq(current); struct sched_entity *se = &p->se, *curr = cfs_rq->curr; int this_cpu = smp_processor_id(); + struct rq *rq = this_rq(); + unsigned long flags; + + spin_lock_irqsave(&rq->lock, flags); - sched_info_queued(p); + if (unlikely(task_cpu(p) != this_cpu)) + __set_task_cpu(p, this_cpu); update_curr(cfs_rq); + if (curr) se->vruntime = curr->vruntime; place_entity(cfs_rq, se, 1); - /* 'curr' will be NULL if the child belongs to a different group */ - if (sysctl_sched_child_runs_first && this_cpu == task_cpu(p) && - curr && entity_before(curr, se)) { + if (sysctl_sched_child_runs_first && curr && entity_before(curr, se)) { /* * Upon rescheduling, sched_class::put_prev_task() will place * 'current' within the tree based on its new key value. @@ -1952,7 +1954,7 @@ static void task_new_fair(struct rq *rq, struct task_struct *p) resched_task(rq->curr); } - enqueue_task_fair(rq, p, 0); + spin_unlock_irqrestore(&rq->lock, flags); } /* @@ -2052,7 +2054,7 @@ static const struct sched_class fair_sched_class = { .set_curr_task = set_curr_task_fair, .task_tick = task_tick_fair, - .task_new = task_new_fair, + .task_fork = task_fork_fair, .prio_changed = prio_changed_fair, .switched_to = switched_to_fair, |