[PATCH] clean up lock_cpu_hotplug() in cpufreq

[linux-2.6] / kernel / sched.c

diff --git a/kernel/sched.c b/kernel/sched.c
index 0f2def822296cae1dfc2eb9710b6b05e3c07a3d9..6f46c94cc29ea4f46d79eb50b36da77208024df3 100644 (file)
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -815,7 +815,8 @@ static void activate_task(task_t *p, runqueue_t *rq, int local)
        }
 #endif
 
-       p->prio = recalc_task_prio(p, now);
+       if (!rt_task(p))
+               p->prio = recalc_task_prio(p, now);
 
        /*
         * This checks to make sure it's not an uninterruptible task
@@ -864,21 +865,28 @@ static void deactivate_task(struct task_struct *p, runqueue_t *rq)
 #ifdef CONFIG_SMP
 static void resched_task(task_t *p)
 {
-       int need_resched, nrpolling;
+       int cpu;
 
        assert_spin_locked(&task_rq(p)->lock);
 
-       /* minimise the chance of sending an interrupt to poll_idle() */
-       nrpolling = test_tsk_thread_flag(p,TIF_POLLING_NRFLAG);
-       need_resched = test_and_set_tsk_thread_flag(p,TIF_NEED_RESCHED);
-       nrpolling |= test_tsk_thread_flag(p,TIF_POLLING_NRFLAG);
+       if (unlikely(test_tsk_thread_flag(p, TIF_NEED_RESCHED)))
+               return;
+
+       set_tsk_thread_flag(p, TIF_NEED_RESCHED);
+
+       cpu = task_cpu(p);
+       if (cpu == smp_processor_id())
+               return;
 
-       if (!need_resched && !nrpolling && (task_cpu(p) != smp_processor_id()))
-               smp_send_reschedule(task_cpu(p));
+       /* NEED_RESCHED must be visible before we test POLLING_NRFLAG */
+       smp_mb();
+       if (!test_tsk_thread_flag(p, TIF_POLLING_NRFLAG))
+               smp_send_reschedule(cpu);
 }
 #else
 static inline void resched_task(task_t *p)
 {
+       assert_spin_locked(&task_rq(p)->lock);
        set_tsk_need_resched(p);
 }
 #endif
@@ -1429,7 +1437,7 @@ void fastcall sched_fork(task_t *p, int clone_flags)
 #endif
 #ifdef CONFIG_PREEMPT
        /* Want to start with kernel preemption disabled. */
-       p->thread_info->preempt_count = 1;
+       task_thread_info(p)->preempt_count = 1;
 #endif
        /*
         * Share the timeslice between parent and child, thus the
@@ -4319,10 +4327,10 @@ static void show_task(task_t *p)
 #endif
 #ifdef CONFIG_DEBUG_STACK_USAGE
        {
-               unsigned long *n = (unsigned long *) (p->thread_info+1);
+               unsigned long *n = end_of_stack(p);
                while (!*n)
                        n++;
-               free = (unsigned long) n - (unsigned long)(p->thread_info+1);
+               free = (unsigned long)n - (unsigned long)end_of_stack(p);
        }
 #endif
        printk("%5lu %5d %6d ", free, p->pid, p->parent->pid);
@@ -4402,9 +4410,9 @@ void __devinit init_idle(task_t *idle, int cpu)
 
        /* Set the preempt count _outside_ the spinlocks! */
 #if defined(CONFIG_PREEMPT) && !defined(CONFIG_PREEMPT_BKL)
-       idle->thread_info->preempt_count = (idle->lock_depth >= 0);
+       task_thread_info(idle)->preempt_count = (idle->lock_depth >= 0);
 #else
-       idle->thread_info->preempt_count = 0;
+       task_thread_info(idle)->preempt_count = 0;
 #endif
 }