hlist: drop the node parameter from iterators

[linux-2.6-microblaze.git] / kernel / sched / core.c

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 3a673a3..12af427 100644 (file)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1132,18 +1132,28 @@ EXPORT_SYMBOL_GPL(kick_process);
  */
 static int select_fallback_rq(int cpu, struct task_struct *p)
 {
-       const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(cpu));
+       int nid = cpu_to_node(cpu);
+       const struct cpumask *nodemask = NULL;
        enum { cpuset, possible, fail } state = cpuset;
        int dest_cpu;
 
-       /* Look for allowed, online CPU in same node. */
-       for_each_cpu(dest_cpu, nodemask) {
-               if (!cpu_online(dest_cpu))
-                       continue;
-               if (!cpu_active(dest_cpu))
-                       continue;
-               if (cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p)))
-                       return dest_cpu;
+       /*
+        * If the node that the cpu is on has been offlined, cpu_to_node()
+        * will return -1. There is no cpu on the node, and we should
+        * select the cpu on the other node.
+        */
+       if (nid != -1) {
+               nodemask = cpumask_of_node(nid);
+
+               /* Look for allowed, online CPU in same node. */
+               for_each_cpu(dest_cpu, nodemask) {
+                       if (!cpu_online(dest_cpu))
+                               continue;
+                       if (!cpu_active(dest_cpu))
+                               continue;
+                       if (cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p)))
+                               return dest_cpu;
+               }
        }
 
        for (;;) {
@@ -1742,9 +1752,8 @@ EXPORT_SYMBOL_GPL(preempt_notifier_unregister);
 static void fire_sched_in_preempt_notifiers(struct task_struct *curr)
 {
        struct preempt_notifier *notifier;
-       struct hlist_node *node;
 
-       hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link)
+       hlist_for_each_entry(notifier, &curr->preempt_notifiers, link)
                notifier->ops->sched_in(notifier, raw_smp_processor_id());
 }
 
@@ -1753,9 +1762,8 @@ fire_sched_out_preempt_notifiers(struct task_struct *curr,
                                 struct task_struct *next)
 {
        struct preempt_notifier *notifier;
-       struct hlist_node *node;
 
-       hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link)
+       hlist_for_each_entry(notifier, &curr->preempt_notifiers, link)
                notifier->ops->sched_out(notifier, next);
 }
 
@@ -1969,11 +1977,10 @@ context_switch(struct rq *rq, struct task_struct *prev,
 }
 
 /*
- * nr_running, nr_uninterruptible and nr_context_switches:
+ * nr_running and nr_context_switches:
  *
  * externally visible scheduler statistics: current number of runnable
- * threads, current number of uninterruptible-sleeping threads, total
- * number of context switches performed since bootup.
+ * threads, total number of context switches performed since bootup.
  */
 unsigned long nr_running(void)
 {
@@ -1985,23 +1992,6 @@ unsigned long nr_running(void)
        return sum;
 }
 
-unsigned long nr_uninterruptible(void)
-{
-       unsigned long i, sum = 0;
-
-       for_each_possible_cpu(i)
-               sum += cpu_rq(i)->nr_uninterruptible;
-
-       /*
-        * Since we read the counters lockless, it might be slightly
-        * inaccurate. Do not allow it to go below zero though:
-        */
-       if (unlikely((long)sum < 0))
-               sum = 0;
-
-       return sum;
-}
-
 unsigned long long nr_context_switches(void)
 {
        int i;
@@ -2786,7 +2776,7 @@ static noinline void __schedule_bug(struct task_struct *prev)
        if (irqs_disabled())
                print_irqtrace_events(prev);
        dump_stack();
-       add_taint(TAINT_WARN);
+       add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
 }
 
 /*
@@ -4364,7 +4354,10 @@ EXPORT_SYMBOL(yield);
  * It's the caller's job to ensure that the target task struct
  * can't go away on us before we can do any checks.
  *
- * Returns true if we indeed boosted the target task.
+ * Returns:
+ *     true (>0) if we indeed boosted the target task.
+ *     false (0) if we failed to boost the target.
+ *     -ESRCH if there's no task to yield to.
  */
 bool __sched yield_to(struct task_struct *p, bool preempt)
 {
@@ -4378,6 +4371,15 @@ bool __sched yield_to(struct task_struct *p, bool preempt)
 
 again:
        p_rq = task_rq(p);
+       /*
+        * If we're the only runnable task on the rq and target rq also
+        * has only one task, there's absolutely no point in yielding.
+        */
+       if (rq->nr_running == 1 && p_rq->nr_running == 1) {
+               yielded = -ESRCH;
+               goto out_irq;
+       }
+
        double_rq_lock(rq, p_rq);
        while (task_rq(p) != p_rq) {
                double_rq_unlock(rq, p_rq);
@@ -4385,13 +4387,13 @@ again:
        }
 
        if (!curr->sched_class->yield_to_task)
-               goto out;
+               goto out_unlock;
 
        if (curr->sched_class != p->sched_class)
-               goto out;
+               goto out_unlock;
 
        if (task_running(p_rq, p) || p->state)
-               goto out;
+               goto out_unlock;
 
        yielded = curr->sched_class->yield_to_task(rq, p, preempt);
        if (yielded) {
@@ -4404,11 +4406,12 @@ again:
                        resched_task(p_rq->curr);
        }
 
-out:
+out_unlock:
        double_rq_unlock(rq, p_rq);
+out_irq:
        local_irq_restore(flags);
 
-       if (yielded)
+       if (yielded > 0)
                schedule();
 
        return yielded;