Merge branch 'sched/urgent' into sched/devel
[pandora-kernel.git] / kernel / sched.c
index c237624..85cf246 100644 (file)
@@ -571,8 +571,10 @@ struct rq {
 #endif
 
 #ifdef CONFIG_SCHED_HRTICK
-       unsigned long hrtick_flags;
-       ktime_t hrtick_expire;
+#ifdef CONFIG_SMP
+       int hrtick_csd_pending;
+       struct call_single_data hrtick_csd;
+#endif
        struct hrtimer hrtick_timer;
 #endif
 
@@ -983,13 +985,6 @@ static struct rq *this_rq_lock(void)
        return rq;
 }
 
-static void __resched_task(struct task_struct *p, int tif_bit);
-
-static inline void resched_task(struct task_struct *p)
-{
-       __resched_task(p, TIF_NEED_RESCHED);
-}
-
 #ifdef CONFIG_SCHED_HRTICK
 /*
  * Use HR-timers to deliver accurate preemption points.
@@ -1001,25 +996,6 @@ static inline void resched_task(struct task_struct *p)
  * When we get rescheduled we reprogram the hrtick_timer outside of the
  * rq->lock.
  */
-static inline void resched_hrt(struct task_struct *p)
-{
-       __resched_task(p, TIF_HRTICK_RESCHED);
-}
-
-static inline void resched_rq(struct rq *rq)
-{
-       unsigned long flags;
-
-       spin_lock_irqsave(&rq->lock, flags);
-       resched_task(rq->curr);
-       spin_unlock_irqrestore(&rq->lock, flags);
-}
-
-enum {
-       HRTICK_SET,             /* re-programm hrtick_timer */
-       HRTICK_RESET,           /* not a new slice */
-       HRTICK_BLOCK,           /* stop hrtick operations */
-};
 
 /*
  * Use hrtick when:
@@ -1030,72 +1006,17 @@ static inline int hrtick_enabled(struct rq *rq)
 {
        if (!sched_feat(HRTICK))
                return 0;
-       if (unlikely(test_bit(HRTICK_BLOCK, &rq->hrtick_flags)))
+       if (!cpu_online(cpu_of(rq)))
                return 0;
        return hrtimer_is_hres_active(&rq->hrtick_timer);
 }
 
-/*
- * Called to set the hrtick timer state.
- *
- * called with rq->lock held and irqs disabled
- */
-static void hrtick_start(struct rq *rq, u64 delay, int reset)
-{
-       assert_spin_locked(&rq->lock);
-
-       /*
-        * preempt at: now + delay
-        */
-       rq->hrtick_expire =
-               ktime_add_ns(rq->hrtick_timer.base->get_time(), delay);
-       /*
-        * indicate we need to program the timer
-        */
-       __set_bit(HRTICK_SET, &rq->hrtick_flags);
-       if (reset)
-               __set_bit(HRTICK_RESET, &rq->hrtick_flags);
-
-       /*
-        * New slices are called from the schedule path and don't need a
-        * forced reschedule.
-        */
-       if (reset)
-               resched_hrt(rq->curr);
-}
-
 static void hrtick_clear(struct rq *rq)
 {
        if (hrtimer_active(&rq->hrtick_timer))
                hrtimer_cancel(&rq->hrtick_timer);
 }
 
-/*
- * Update the timer from the possible pending state.
- */
-static void hrtick_set(struct rq *rq)
-{
-       ktime_t time;
-       int set, reset;
-       unsigned long flags;
-
-       WARN_ON_ONCE(cpu_of(rq) != smp_processor_id());
-
-       spin_lock_irqsave(&rq->lock, flags);
-       set = __test_and_clear_bit(HRTICK_SET, &rq->hrtick_flags);
-       reset = __test_and_clear_bit(HRTICK_RESET, &rq->hrtick_flags);
-       time = rq->hrtick_expire;
-       clear_thread_flag(TIF_HRTICK_RESCHED);
-       spin_unlock_irqrestore(&rq->lock, flags);
-
-       if (set) {
-               hrtimer_start(&rq->hrtick_timer, time, HRTIMER_MODE_ABS);
-               if (reset && !hrtimer_active(&rq->hrtick_timer))
-                       resched_rq(rq);
-       } else
-               hrtick_clear(rq);
-}
-
 /*
  * High-resolution timer tick.
  * Runs from hardirq context with interrupts disabled.
@@ -1115,27 +1036,37 @@ static enum hrtimer_restart hrtick(struct hrtimer *timer)
 }
 
 #ifdef CONFIG_SMP
-static void hotplug_hrtick_disable(int cpu)
+/*
+ * called from hardirq (IPI) context
+ */
+static void __hrtick_start(void *arg)
 {
-       struct rq *rq = cpu_rq(cpu);
-       unsigned long flags;
-
-       spin_lock_irqsave(&rq->lock, flags);
-       rq->hrtick_flags = 0;
-       __set_bit(HRTICK_BLOCK, &rq->hrtick_flags);
-       spin_unlock_irqrestore(&rq->lock, flags);
+       struct rq *rq = arg;
 
-       hrtick_clear(rq);
+       spin_lock(&rq->lock);
+       hrtimer_restart(&rq->hrtick_timer);
+       rq->hrtick_csd_pending = 0;
+       spin_unlock(&rq->lock);
 }
 
-static void hotplug_hrtick_enable(int cpu)
+/*
+ * Called to set the hrtick timer state.
+ *
+ * called with rq->lock held and irqs disabled
+ */
+static void hrtick_start(struct rq *rq, u64 delay)
 {
-       struct rq *rq = cpu_rq(cpu);
-       unsigned long flags;
+       struct hrtimer *timer = &rq->hrtick_timer;
+       ktime_t time = ktime_add_ns(timer->base->get_time(), delay);
 
-       spin_lock_irqsave(&rq->lock, flags);
-       __clear_bit(HRTICK_BLOCK, &rq->hrtick_flags);
-       spin_unlock_irqrestore(&rq->lock, flags);
+       timer->expires = time;
+
+       if (rq == this_rq()) {
+               hrtimer_restart(timer);
+       } else if (!rq->hrtick_csd_pending) {
+               __smp_call_function_single(cpu_of(rq), &rq->hrtick_csd);
+               rq->hrtick_csd_pending = 1;
+       }
 }
 
 static int
@@ -1150,16 +1081,7 @@ hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu)
        case CPU_DOWN_PREPARE_FROZEN:
        case CPU_DEAD:
        case CPU_DEAD_FROZEN:
-               hotplug_hrtick_disable(cpu);
-               return NOTIFY_OK;
-
-       case CPU_UP_PREPARE:
-       case CPU_UP_PREPARE_FROZEN:
-       case CPU_DOWN_FAILED:
-       case CPU_DOWN_FAILED_FROZEN:
-       case CPU_ONLINE:
-       case CPU_ONLINE_FROZEN:
-               hotplug_hrtick_enable(cpu);
+               hrtick_clear(cpu_rq(cpu));
                return NOTIFY_OK;
        }
 
@@ -1170,46 +1092,45 @@ static void init_hrtick(void)
 {
        hotcpu_notifier(hotplug_hrtick, 0);
 }
-#endif /* CONFIG_SMP */
+#else
+/*
+ * Called to set the hrtick timer state.
+ *
+ * called with rq->lock held and irqs disabled
+ */
+static void hrtick_start(struct rq *rq, u64 delay)
+{
+       hrtimer_start(&rq->hrtick_timer, ns_to_ktime(delay), HRTIMER_MODE_REL);
+}
 
-static void init_rq_hrtick(struct rq *rq)
+static void init_hrtick(void)
 {
-       rq->hrtick_flags = 0;
-       hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
-       rq->hrtick_timer.function = hrtick;
-       rq->hrtick_timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ;
 }
+#endif /* CONFIG_SMP */
 
-void hrtick_resched(void)
+static void init_rq_hrtick(struct rq *rq)
 {
-       struct rq *rq;
-       unsigned long flags;
+#ifdef CONFIG_SMP
+       rq->hrtick_csd_pending = 0;
 
-       if (!test_thread_flag(TIF_HRTICK_RESCHED))
-               return;
+       rq->hrtick_csd.flags = 0;
+       rq->hrtick_csd.func = __hrtick_start;
+       rq->hrtick_csd.info = rq;
+#endif
 
-       local_irq_save(flags);
-       rq = cpu_rq(smp_processor_id());
-       hrtick_set(rq);
-       local_irq_restore(flags);
+       hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+       rq->hrtick_timer.function = hrtick;
+       rq->hrtick_timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ;
 }
 #else
 static inline void hrtick_clear(struct rq *rq)
 {
 }
 
-static inline void hrtick_set(struct rq *rq)
-{
-}
-
 static inline void init_rq_hrtick(struct rq *rq)
 {
 }
 
-void hrtick_resched(void)
-{
-}
-
 static inline void init_hrtick(void)
 {
 }
@@ -1228,16 +1149,16 @@ static inline void init_hrtick(void)
 #define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG)
 #endif
 
-static void __resched_task(struct task_struct *p, int tif_bit)
+static void resched_task(struct task_struct *p)
 {
        int cpu;
 
        assert_spin_locked(&task_rq(p)->lock);
 
-       if (unlikely(test_tsk_thread_flag(p, tif_bit)))
+       if (unlikely(test_tsk_thread_flag(p, TIF_NEED_RESCHED)))
                return;
 
-       set_tsk_thread_flag(p, tif_bit);
+       set_tsk_thread_flag(p, TIF_NEED_RESCHED);
 
        cpu = task_cpu(p);
        if (cpu == smp_processor_id())
@@ -1303,10 +1224,10 @@ void wake_up_idle_cpu(int cpu)
 #endif /* CONFIG_NO_HZ */
 
 #else /* !CONFIG_SMP */
-static void __resched_task(struct task_struct *p, int tif_bit)
+static void resched_task(struct task_struct *p)
 {
        assert_spin_locked(&task_rq(p)->lock);
-       set_tsk_thread_flag(p, tif_bit);
+       set_tsk_need_resched(p);
 }
 #endif /* CONFIG_SMP */
 
@@ -4395,7 +4316,7 @@ asmlinkage void __sched schedule(void)
        struct task_struct *prev, *next;
        unsigned long *switch_count;
        struct rq *rq;
-       int cpu, hrtick = sched_feat(HRTICK);
+       int cpu;
 
 need_resched:
        preempt_disable();
@@ -4410,7 +4331,7 @@ need_resched_nonpreemptible:
 
        schedule_debug(prev);
 
-       if (hrtick)
+       if (sched_feat(HRTICK))
                hrtick_clear(rq);
 
        /*
@@ -4457,9 +4378,6 @@ need_resched_nonpreemptible:
        } else
                spin_unlock_irq(&rq->lock);
 
-       if (hrtick)
-               hrtick_set(rq);
-
        if (unlikely(reacquire_kernel_lock(current) < 0))
                goto need_resched_nonpreemptible;