Merge branch 'for-linus' of git://oss.sgi.com:8090/xfs/xfs-2.6

[~andy/linux] / kernel / sched.c

diff --git a/kernel/sched.c b/kernel/sched.c
index f28f19e65b598af5dca9c8985af38febfaada9ff..f06950c8a6ce17b95624bccc63ecfb399d2eb40c 100644 (file)
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -668,6 +668,8 @@ const_debug unsigned int sysctl_sched_nr_migrate = 32;
  */
 unsigned int sysctl_sched_rt_period = 1000000;
 
+static __read_mostly int scheduler_running;
+
 /*
  * part of the period that we allow rt tasks to run in us.
  * default: 0.95s
@@ -689,14 +691,16 @@ unsigned long long cpu_clock(int cpu)
        unsigned long flags;
        struct rq *rq;
 
-       local_irq_save(flags);
-       rq = cpu_rq(cpu);
        /*
         * Only call sched_clock() if the scheduler has already been
         * initialized (some code might call cpu_clock() very early):
         */
-       if (rq->idle)
-               update_rq_clock(rq);
+       if (unlikely(!scheduler_running))
+               return 0;
+
+       local_irq_save(flags);
+       rq = cpu_rq(cpu);
+       update_rq_clock(rq);
        now = rq->clock;
        local_irq_restore(flags);
 
@@ -1831,6 +1835,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
        long old_state;
        struct rq *rq;
 
+       smp_wmb();
        rq = task_rq_lock(p, &flags);
        old_state = p->state;
        if (!(old_state & state))
@@ -3766,7 +3771,7 @@ void scheduler_tick(void)
 
 #if defined(CONFIG_PREEMPT) && defined(CONFIG_DEBUG_PREEMPT)
 
-void add_preempt_count(int val)
+void __kprobes add_preempt_count(int val)
 {
        /*
         * Underflow?
@@ -3782,7 +3787,7 @@ void add_preempt_count(int val)
 }
 EXPORT_SYMBOL(add_preempt_count);
 
-void sub_preempt_count(int val)
+void __kprobes sub_preempt_count(int val)
 {
        /*
         * Underflow?
@@ -3884,7 +3889,7 @@ pick_next_task(struct rq *rq, struct task_struct *prev)
 asmlinkage void __sched schedule(void)
 {
        struct task_struct *prev, *next;
-       long *switch_count;
+       unsigned long *switch_count;
        struct rq *rq;
        int cpu;
 
@@ -7283,6 +7288,8 @@ void __init sched_init(void)
         * During early bootup we pretend to be a normal task:
         */
        current->sched_class = &fair_sched_class;
+
+       scheduler_running = 1;
 }
 
 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP