Reset to 3.12.37

1 files changed, 19 insertions, 124 deletions

diff --git a/kernel/timer.c b/kernel/timer.c
index cc34e42..4addfa2 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -78,9 +78,6 @@ struct tvec_root {
 struct tvec_base {
 	spinlock_t lock;
 	struct timer_list *running_timer;
-#ifdef CONFIG_PREEMPT_RT_FULL
-	wait_queue_head_t wait_for_running_timer;
-#endif
 	unsigned long timer_jiffies;
 	unsigned long next_timer;
 	unsigned long active_timers;
@@ -723,36 +720,6 @@ static struct tvec_base *lock_timer_base(struct timer_list *timer,
 	}
 }
 
-#ifndef CONFIG_PREEMPT_RT_FULL
-static inline struct tvec_base *switch_timer_base(struct timer_list *timer,
-						  struct tvec_base *old,
-						  struct tvec_base *new)
-{
-	/* See the comment in lock_timer_base() */
-	timer_set_base(timer, NULL);
-	spin_unlock(&old->lock);
-	spin_lock(&new->lock);
-	timer_set_base(timer, new);
-	return new;
-}
-#else
-static inline struct tvec_base *switch_timer_base(struct timer_list *timer,
-						  struct tvec_base *old,
-						  struct tvec_base *new)
-{
-	/*
-	 * We cannot do the above because we might be preempted and
-	 * then the preempter would see NULL and loop forever.
-	 */
-	if (spin_trylock(&new->lock)) {
-		timer_set_base(timer, new);
-		spin_unlock(&old->lock);
-		return new;
-	}
-	return old;
-}
-#endif
-
 static inline int
 __mod_timer(struct timer_list *timer, unsigned long expires,
 						bool pending_only, int pinned)
@@ -772,15 +739,12 @@ __mod_timer(struct timer_list *timer, unsigned long expires,
 
 	debug_activate(timer, expires);
 
-	preempt_disable_rt();
 	cpu = smp_processor_id();
 
 #if defined(CONFIG_NO_HZ_COMMON) && defined(CONFIG_SMP)
 	if (!pinned && get_sysctl_timer_migration() && idle_cpu(cpu))
 		cpu = get_nohz_timer_target();
 #endif
-	preempt_enable_rt();
-
 	new_base = per_cpu(tvec_bases, cpu);
 
 	if (base != new_base) {
@@ -791,8 +755,14 @@ __mod_timer(struct timer_list *timer, unsigned long expires,
 		 * handler yet has not finished. This also guarantees that
 		 * the timer is serialized wrt itself.
 		 */
-		if (likely(base->running_timer != timer))
-			base = switch_timer_base(timer, base, new_base);
+		if (likely(base->running_timer != timer)) {
+			/* See the comment in lock_timer_base() */
+			timer_set_base(timer, NULL);
+			spin_unlock(&base->lock);
+			base = new_base;
+			spin_lock(&base->lock);
+			timer_set_base(timer, base);
+		}
 	}
 
 	timer->expires = expires;
@@ -852,7 +822,7 @@ unsigned long apply_slack(struct timer_list *timer, unsigned long expires)
 
 	bit = find_last_bit(&mask, BITS_PER_LONG);
 
-	mask = (1 << bit) - 1;
+	mask = (1UL << bit) - 1;
 
 	expires_limit = expires_limit & ~(mask);
 
@@ -975,29 +945,6 @@ void add_timer_on(struct timer_list *timer, int cpu)
 }
 EXPORT_SYMBOL_GPL(add_timer_on);
 
-#ifdef CONFIG_PREEMPT_RT_FULL
-/*
- * Wait for a running timer
- */
-static void wait_for_running_timer(struct timer_list *timer)
-{
-	struct tvec_base *base = timer->base;
-
-	if (base->running_timer == timer)
-		wait_event(base->wait_for_running_timer,
-			   base->running_timer != timer);
-}
-
-# define wakeup_timer_waiters(b)	wake_up(&(b)->wait_for_running_timer)
-#else
-static inline void wait_for_running_timer(struct timer_list *timer)
-{
-	cpu_relax();
-}
-
-# define wakeup_timer_waiters(b)	do { } while (0)
-#endif
-
 /**
  * del_timer - deactive a timer.
  * @timer: the timer to be deactivated
@@ -1055,7 +1002,7 @@ int try_to_del_timer_sync(struct timer_list *timer)
 }
 EXPORT_SYMBOL(try_to_del_timer_sync);
 
-#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT_FULL)
+#ifdef CONFIG_SMP
 /**
  * del_timer_sync - deactivate a timer and wait for the handler to finish.
  * @timer: the timer to be deactivated
@@ -1115,7 +1062,7 @@ int del_timer_sync(struct timer_list *timer)
 		int ret = try_to_del_timer_sync(timer);
 		if (ret >= 0)
 			return ret;
-		wait_for_running_timer(timer);
+		cpu_relax();
 	}
 }
 EXPORT_SYMBOL(del_timer_sync);
@@ -1232,17 +1179,15 @@ static inline void __run_timers(struct tvec_base *base)
 			if (irqsafe) {
 				spin_unlock(&base->lock);
 				call_timer_fn(timer, fn, data);
-				base->running_timer = NULL;
 				spin_lock(&base->lock);
 			} else {
 				spin_unlock_irq(&base->lock);
 				call_timer_fn(timer, fn, data);
-				base->running_timer = NULL;
 				spin_lock_irq(&base->lock);
 			}
 		}
 	}
-	wakeup_timer_waiters(base);
+	base->running_timer = NULL;
 	spin_unlock_irq(&base->lock);
 }
 
@@ -1382,31 +1327,17 @@ unsigned long get_next_timer_interrupt(unsigned long now)
 	if (cpu_is_offline(smp_processor_id()))
 		return expires;
 
-#ifdef CONFIG_PREEMPT_RT_FULL
-	/*
-	 * On PREEMPT_RT we cannot sleep here. If the trylock does not
-	 * succeed then we return the worst-case 'expires in 1 tick'
-	 * value.  We use the rt functions here directly to avoid a
-	 * migrate_disable() call.
-	 */
-	if (!spin_do_trylock(&base->lock))
-		return  now + 1;
-#else
 	spin_lock(&base->lock);
-#endif
 	if (base->active_timers) {
 		if (time_before_eq(base->next_timer, base->timer_jiffies))
 			base->next_timer = __next_timer_interrupt(base);
 		expires = base->next_timer;
 	}
-#ifdef CONFIG_PREEMPT_RT_FULL
-	rt_spin_unlock_after_trylock_in_irq(&base->lock);
-#else
 	spin_unlock(&base->lock);
-#endif
 
 	if (time_before_eq(expires, now))
 		return now;
+
 	return cmp_next_hrtimer_event(now, expires);
 }
 #endif
@@ -1422,13 +1353,13 @@ void update_process_times(int user_tick)
 
 	/* Note: this timer irq context must be accounted for as well. */
 	account_process_tick(p, user_tick);
-	scheduler_tick();
 	run_local_timers();
 	rcu_check_callbacks(cpu, user_tick);
-#if defined(CONFIG_IRQ_WORK)
+#ifdef CONFIG_IRQ_WORK
 	if (in_irq())
 		irq_work_run();
 #endif
+	scheduler_tick();
 	run_posix_cpu_timers(p);
 }
 
@@ -1439,9 +1370,7 @@ static void run_timer_softirq(struct softirq_action *h)
 {
 	struct tvec_base *base = __this_cpu_read(tvec_bases);
 
-#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_PREEMPT_RT_FULL)
-	irq_work_run();
-#endif
+	hrtimer_run_pending();
 
 	if (time_after_eq(jiffies, base->timer_jiffies))
 		__run_timers(base);
@@ -1452,39 +1381,8 @@ static void run_timer_softirq(struct softirq_action *h)
  */
 void run_local_timers(void)
 {
-	struct tvec_base *base = __this_cpu_read(tvec_bases);
-
 	hrtimer_run_queues();
-	/*
-	 * We can access this lockless as we are in the timer
-	 * interrupt. If there are no timers queued, nothing to do in
-	 * the timer softirq.
-	 */
-#ifdef CONFIG_PREEMPT_RT_FULL
-	/* On RT, irq work runs from softirq */
-	if (irq_work_needs_cpu()) {
-		raise_softirq(TIMER_SOFTIRQ);
-		return;
-	}
-
-	if (!spin_do_trylock(&base->lock)) {
-		raise_softirq(TIMER_SOFTIRQ);
-		return;
-	}
-#endif
-
-	if (!base->active_timers)
-		goto out;
-
-	/* Check whether the next pending timer has expired */
-	if (time_before_eq(base->next_timer, jiffies))
-		raise_softirq(TIMER_SOFTIRQ);
-out:
-#ifdef CONFIG_PREEMPT_RT_FULL
-	rt_spin_unlock_after_trylock_in_irq(&base->lock);
-#endif
-	/* The ; ensures that gcc won't complain in the !RT case */
-	;
+	raise_softirq(TIMER_SOFTIRQ);
 }
 
 #ifdef __ARCH_WANT_SYS_ALARM
@@ -1649,9 +1547,6 @@ static int init_timers_cpu(int cpu)
 		base = per_cpu(tvec_bases, cpu);
 	}
 
-#ifdef CONFIG_PREEMPT_RT_FULL
-	init_waitqueue_head(&base->wait_for_running_timer);
-#endif
 
 	for (j = 0; j < TVN_SIZE; j++) {
 		INIT_LIST_HEAD(base->tv5.vec + j);
@@ -1690,7 +1585,7 @@ static void migrate_timers(int cpu)
 
 	BUG_ON(cpu_online(cpu));
 	old_base = per_cpu(tvec_bases, cpu);
-	new_base = get_local_var(tvec_bases);
+	new_base = get_cpu_var(tvec_bases);
 	/*
 	 * The caller is globally serialized and nobody else
 	 * takes two locks at once, deadlock is not possible.
@@ -1711,7 +1606,7 @@ static void migrate_timers(int cpu)
 
 	spin_unlock(&old_base->lock);
 	spin_unlock_irq(&new_base->lock);
-	put_local_var(tvec_bases);
+	put_cpu_var(tvec_bases);
 }
 #endif /* CONFIG_HOTPLUG_CPU */