sched: cleanup: remove unnecessary gotos
Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Andi Kleen
Ingo Molnar
parent
d274a4cee1
commit
3a5c359a58
1 changed files with 169 additions and 172 deletions
341
kernel/sched.c
341
kernel/sched.c
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@ -562,16 +562,13 @@ static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
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static inline struct rq *__task_rq_lock(struct task_struct *p)
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__acquires(rq->lock)
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{
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struct rq *rq;
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repeat_lock_task:
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rq = task_rq(p);
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spin_lock(&rq->lock);
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if (unlikely(rq != task_rq(p))) {
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for (;;) {
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struct rq *rq = task_rq(p);
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spin_lock(&rq->lock);
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if (likely(rq == task_rq(p)))
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return rq;
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spin_unlock(&rq->lock);
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goto repeat_lock_task;
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}
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return rq;
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}
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/*
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@ -584,15 +581,14 @@ static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags)
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{
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struct rq *rq;
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repeat_lock_task:
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local_irq_save(*flags);
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rq = task_rq(p);
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spin_lock(&rq->lock);
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if (unlikely(rq != task_rq(p))) {
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for (;;) {
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local_irq_save(*flags);
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rq = task_rq(p);
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spin_lock(&rq->lock);
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if (likely(rq == task_rq(p)))
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return rq;
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spin_unlock_irqrestore(&rq->lock, *flags);
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goto repeat_lock_task;
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}
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return rq;
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}
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static void __task_rq_unlock(struct rq *rq)
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@ -1083,69 +1079,71 @@ void wait_task_inactive(struct task_struct *p)
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int running, on_rq;
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struct rq *rq;
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repeat:
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/*
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* We do the initial early heuristics without holding
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* any task-queue locks at all. We'll only try to get
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* the runqueue lock when things look like they will
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* work out!
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*/
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rq = task_rq(p);
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for (;;) {
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/*
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* We do the initial early heuristics without holding
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* any task-queue locks at all. We'll only try to get
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* the runqueue lock when things look like they will
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* work out!
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*/
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rq = task_rq(p);
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/*
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* If the task is actively running on another CPU
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* still, just relax and busy-wait without holding
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* any locks.
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*
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* NOTE! Since we don't hold any locks, it's not
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* even sure that "rq" stays as the right runqueue!
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* But we don't care, since "task_running()" will
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* return false if the runqueue has changed and p
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* is actually now running somewhere else!
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*/
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while (task_running(rq, p))
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cpu_relax();
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/*
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* If the task is actively running on another CPU
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* still, just relax and busy-wait without holding
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* any locks.
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*
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* NOTE! Since we don't hold any locks, it's not
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* even sure that "rq" stays as the right runqueue!
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* But we don't care, since "task_running()" will
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* return false if the runqueue has changed and p
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* is actually now running somewhere else!
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*/
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while (task_running(rq, p))
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cpu_relax();
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/*
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* Ok, time to look more closely! We need the rq
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* lock now, to be *sure*. If we're wrong, we'll
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* just go back and repeat.
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*/
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rq = task_rq_lock(p, &flags);
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running = task_running(rq, p);
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on_rq = p->se.on_rq;
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task_rq_unlock(rq, &flags);
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/*
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* Ok, time to look more closely! We need the rq
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* lock now, to be *sure*. If we're wrong, we'll
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* just go back and repeat.
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*/
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rq = task_rq_lock(p, &flags);
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running = task_running(rq, p);
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on_rq = p->se.on_rq;
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task_rq_unlock(rq, &flags);
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/*
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* Was it really running after all now that we
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* checked with the proper locks actually held?
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*
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* Oops. Go back and try again..
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*/
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if (unlikely(running)) {
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cpu_relax();
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goto repeat;
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/*
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* Was it really running after all now that we
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* checked with the proper locks actually held?
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*
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* Oops. Go back and try again..
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*/
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if (unlikely(running)) {
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cpu_relax();
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continue;
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}
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/*
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* It's not enough that it's not actively running,
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* it must be off the runqueue _entirely_, and not
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* preempted!
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*
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* So if it wa still runnable (but just not actively
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* running right now), it's preempted, and we should
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* yield - it could be a while.
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*/
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if (unlikely(on_rq)) {
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schedule_timeout_uninterruptible(1);
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continue;
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}
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/*
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* Ahh, all good. It wasn't running, and it wasn't
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* runnable, which means that it will never become
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* running in the future either. We're all done!
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*/
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break;
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}
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/*
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* It's not enough that it's not actively running,
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* it must be off the runqueue _entirely_, and not
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* preempted!
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*
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* So if it wa still runnable (but just not actively
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* running right now), it's preempted, and we should
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* yield - it could be a while.
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*/
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if (unlikely(on_rq)) {
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schedule_timeout_uninterruptible(1);
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goto repeat;
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}
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/*
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* Ahh, all good. It wasn't running, and it wasn't
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* runnable, which means that it will never become
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* running in the future either. We're all done!
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*/
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}
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/***
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@ -1236,7 +1234,7 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu)
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/* Skip over this group if it has no CPUs allowed */
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if (!cpus_intersects(group->cpumask, p->cpus_allowed))
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goto nextgroup;
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continue;
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local_group = cpu_isset(this_cpu, group->cpumask);
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@ -1264,9 +1262,7 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu)
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min_load = avg_load;
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idlest = group;
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}
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nextgroup:
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group = group->next;
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} while (group != sd->groups);
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} while (group = group->next, group != sd->groups);
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if (!idlest || 100*this_load < imbalance*min_load)
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return NULL;
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@ -3517,27 +3513,30 @@ asmlinkage void __sched preempt_schedule(void)
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if (likely(ti->preempt_count || irqs_disabled()))
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return;
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need_resched:
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add_preempt_count(PREEMPT_ACTIVE);
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/*
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* We keep the big kernel semaphore locked, but we
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* clear ->lock_depth so that schedule() doesnt
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* auto-release the semaphore:
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*/
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#ifdef CONFIG_PREEMPT_BKL
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saved_lock_depth = task->lock_depth;
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task->lock_depth = -1;
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#endif
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schedule();
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#ifdef CONFIG_PREEMPT_BKL
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task->lock_depth = saved_lock_depth;
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#endif
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sub_preempt_count(PREEMPT_ACTIVE);
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do {
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add_preempt_count(PREEMPT_ACTIVE);
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/* we could miss a preemption opportunity between schedule and now */
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barrier();
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if (unlikely(test_thread_flag(TIF_NEED_RESCHED)))
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goto need_resched;
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/*
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* We keep the big kernel semaphore locked, but we
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* clear ->lock_depth so that schedule() doesnt
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* auto-release the semaphore:
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*/
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#ifdef CONFIG_PREEMPT_BKL
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saved_lock_depth = task->lock_depth;
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task->lock_depth = -1;
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#endif
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schedule();
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#ifdef CONFIG_PREEMPT_BKL
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task->lock_depth = saved_lock_depth;
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#endif
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sub_preempt_count(PREEMPT_ACTIVE);
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/*
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* Check again in case we missed a preemption opportunity
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* between schedule and now.
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*/
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barrier();
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} while (unlikely(test_thread_flag(TIF_NEED_RESCHED)));
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}
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EXPORT_SYMBOL(preempt_schedule);
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@ -3557,29 +3556,32 @@ asmlinkage void __sched preempt_schedule_irq(void)
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/* Catch callers which need to be fixed */
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BUG_ON(ti->preempt_count || !irqs_disabled());
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need_resched:
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add_preempt_count(PREEMPT_ACTIVE);
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/*
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* We keep the big kernel semaphore locked, but we
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* clear ->lock_depth so that schedule() doesnt
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* auto-release the semaphore:
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*/
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#ifdef CONFIG_PREEMPT_BKL
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saved_lock_depth = task->lock_depth;
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task->lock_depth = -1;
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#endif
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local_irq_enable();
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schedule();
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local_irq_disable();
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#ifdef CONFIG_PREEMPT_BKL
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task->lock_depth = saved_lock_depth;
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#endif
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sub_preempt_count(PREEMPT_ACTIVE);
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do {
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add_preempt_count(PREEMPT_ACTIVE);
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/* we could miss a preemption opportunity between schedule and now */
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barrier();
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if (unlikely(test_thread_flag(TIF_NEED_RESCHED)))
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goto need_resched;
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/*
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* We keep the big kernel semaphore locked, but we
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* clear ->lock_depth so that schedule() doesnt
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* auto-release the semaphore:
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*/
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#ifdef CONFIG_PREEMPT_BKL
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saved_lock_depth = task->lock_depth;
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task->lock_depth = -1;
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#endif
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local_irq_enable();
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schedule();
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local_irq_disable();
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#ifdef CONFIG_PREEMPT_BKL
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task->lock_depth = saved_lock_depth;
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#endif
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sub_preempt_count(PREEMPT_ACTIVE);
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/*
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* Check again in case we missed a preemption opportunity
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* between schedule and now.
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*/
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barrier();
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} while (unlikely(test_thread_flag(TIF_NEED_RESCHED)));
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}
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#endif /* CONFIG_PREEMPT */
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@ -4324,10 +4326,10 @@ asmlinkage long sys_sched_setparam(pid_t pid, struct sched_param __user *param)
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asmlinkage long sys_sched_getscheduler(pid_t pid)
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{
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struct task_struct *p;
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int retval = -EINVAL;
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int retval;
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if (pid < 0)
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goto out_nounlock;
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return -EINVAL;
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retval = -ESRCH;
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read_lock(&tasklist_lock);
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@ -4338,8 +4340,6 @@ asmlinkage long sys_sched_getscheduler(pid_t pid)
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retval = p->policy;
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}
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read_unlock(&tasklist_lock);
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out_nounlock:
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return retval;
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}
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@ -4352,10 +4352,10 @@ asmlinkage long sys_sched_getparam(pid_t pid, struct sched_param __user *param)
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{
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struct sched_param lp;
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struct task_struct *p;
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int retval = -EINVAL;
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int retval;
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if (!param || pid < 0)
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goto out_nounlock;
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return -EINVAL;
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read_lock(&tasklist_lock);
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p = find_process_by_pid(pid);
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@ -4375,7 +4375,6 @@ asmlinkage long sys_sched_getparam(pid_t pid, struct sched_param __user *param)
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*/
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retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0;
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out_nounlock:
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return retval;
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out_unlock:
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@ -4731,11 +4730,11 @@ long sys_sched_rr_get_interval(pid_t pid, struct timespec __user *interval)
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{
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struct task_struct *p;
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unsigned int time_slice;
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int retval = -EINVAL;
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int retval;
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struct timespec t;
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if (pid < 0)
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goto out_nounlock;
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return -EINVAL;
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retval = -ESRCH;
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read_lock(&tasklist_lock);
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@ -4763,8 +4762,8 @@ long sys_sched_rr_get_interval(pid_t pid, struct timespec __user *interval)
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read_unlock(&tasklist_lock);
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jiffies_to_timespec(time_slice, &t);
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retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0;
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out_nounlock:
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return retval;
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out_unlock:
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read_unlock(&tasklist_lock);
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return retval;
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@ -5070,35 +5069,34 @@ static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p)
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struct rq *rq;
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int dest_cpu;
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restart:
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/* On same node? */
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mask = node_to_cpumask(cpu_to_node(dead_cpu));
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cpus_and(mask, mask, p->cpus_allowed);
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dest_cpu = any_online_cpu(mask);
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do {
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/* On same node? */
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mask = node_to_cpumask(cpu_to_node(dead_cpu));
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cpus_and(mask, mask, p->cpus_allowed);
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dest_cpu = any_online_cpu(mask);
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/* On any allowed CPU? */
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if (dest_cpu == NR_CPUS)
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dest_cpu = any_online_cpu(p->cpus_allowed);
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/* On any allowed CPU? */
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if (dest_cpu == NR_CPUS)
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dest_cpu = any_online_cpu(p->cpus_allowed);
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/* No more Mr. Nice Guy. */
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if (dest_cpu == NR_CPUS) {
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rq = task_rq_lock(p, &flags);
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cpus_setall(p->cpus_allowed);
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dest_cpu = any_online_cpu(p->cpus_allowed);
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task_rq_unlock(rq, &flags);
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/* No more Mr. Nice Guy. */
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if (dest_cpu == NR_CPUS) {
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rq = task_rq_lock(p, &flags);
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cpus_setall(p->cpus_allowed);
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dest_cpu = any_online_cpu(p->cpus_allowed);
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task_rq_unlock(rq, &flags);
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/*
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* Don't tell them about moving exiting tasks or
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* kernel threads (both mm NULL), since they never
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* leave kernel.
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*/
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if (p->mm && printk_ratelimit())
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printk(KERN_INFO "process %d (%s) no "
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"longer affine to cpu%d\n",
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p->pid, p->comm, dead_cpu);
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}
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if (!__migrate_task(p, dead_cpu, dest_cpu))
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goto restart;
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/*
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* Don't tell them about moving exiting tasks or
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* kernel threads (both mm NULL), since they never
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* leave kernel.
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*/
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if (p->mm && printk_ratelimit())
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printk(KERN_INFO "process %d (%s) no "
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"longer affine to cpu%d\n",
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p->pid, p->comm, dead_cpu);
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}
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} while (!__migrate_task(p, dead_cpu, dest_cpu));
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}
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/*
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@ -5913,24 +5911,23 @@ static void init_numa_sched_groups_power(struct sched_group *group_head)
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if (!sg)
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return;
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next_sg:
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for_each_cpu_mask(j, sg->cpumask) {
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struct sched_domain *sd;
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do {
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for_each_cpu_mask(j, sg->cpumask) {
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struct sched_domain *sd;
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sd = &per_cpu(phys_domains, j);
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if (j != first_cpu(sd->groups->cpumask)) {
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/*
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* Only add "power" once for each
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* physical package.
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*/
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continue;
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sd = &per_cpu(phys_domains, j);
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if (j != first_cpu(sd->groups->cpumask)) {
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/*
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* Only add "power" once for each
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* physical package.
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*/
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continue;
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}
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sg_inc_cpu_power(sg, sd->groups->__cpu_power);
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}
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sg_inc_cpu_power(sg, sd->groups->__cpu_power);
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}
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sg = sg->next;
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if (sg != group_head)
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goto next_sg;
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sg = sg->next;
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} while (sg != group_head);
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}
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#endif
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