X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Fhrtimer.c;h=dea4c9124ac808b872d43a3dd83c15fc7cbb38a9;hb=9e3bd6c3fb2334be171e69b432039cd18bce4458;hp=911e87d0440dee2216f2cbd72fea4ba077d1dd81;hpb=029a07e0311c7fef968d44b50beca53969cee40b;p=safe%2Fjmp%2Flinux-2.6

diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 911e87d..dea4c91 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -590,7 +590,6 @@ static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
 			list_add_tail(&timer->cb_entry,
 				      &base->cpu_base->cb_pending);
 			timer->state = HRTIMER_STATE_PENDING;
-			raise_softirq(HRTIMER_SOFTIRQ);
 			return 1;
 		default:
 			BUG();
@@ -633,6 +632,11 @@ static int hrtimer_switch_to_hres(void)
 	return 1;
 }
 
+static inline void hrtimer_raise_softirq(void)
+{
+	raise_softirq(HRTIMER_SOFTIRQ);
+}
+
 #else
 
 static inline int hrtimer_hres_active(void) { return 0; }
@@ -651,6 +655,7 @@ static inline int hrtimer_reprogram(struct hrtimer *timer,
 {
 	return 0;
 }
+static inline void hrtimer_raise_softirq(void) { }
 
 #endif /* CONFIG_HIGH_RES_TIMERS */
 
@@ -850,7 +855,7 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
 {
 	struct hrtimer_clock_base *base, *new_base;
 	unsigned long flags;
-	int ret;
+	int ret, raise;
 
 	base = lock_hrtimer_base(timer, &flags);
 
@@ -884,8 +889,18 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
 	enqueue_hrtimer(timer, new_base,
 			new_base->cpu_base == &__get_cpu_var(hrtimer_bases));
 
+	/*
+	 * The timer may be expired and moved to the cb_pending
+	 * list. We can not raise the softirq with base lock held due
+	 * to a possible deadlock with runqueue lock.
+	 */
+	raise = timer->state == HRTIMER_STATE_PENDING;
+
 	unlock_hrtimer_base(timer, &flags);
 
+	if (raise)
+		hrtimer_raise_softirq();
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(hrtimer_start);
@@ -1080,8 +1095,19 @@ static void run_hrtimer_pending(struct hrtimer_cpu_base *cpu_base)
 			 * If the timer was rearmed on another CPU, reprogram
 			 * the event device.
 			 */
-			if (timer->base->first == &timer->node)
-				hrtimer_reprogram(timer, timer->base);
+			struct hrtimer_clock_base *base = timer->base;
+
+			if (base->first == &timer->node &&
+			    hrtimer_reprogram(timer, base)) {
+				/*
+				 * Timer is expired. Thus move it from tree to
+				 * pending list again.
+				 */
+				__remove_hrtimer(timer, base,
+						 HRTIMER_STATE_PENDING, 0);
+				list_add_tail(&timer->cb_entry,
+					      &base->cpu_base->cb_pending);
+			}
 		}
 	}
 	spin_unlock_irq(&cpu_base->lock);
@@ -1238,51 +1264,50 @@ void hrtimer_run_pending(void)
 /*
  * Called from hardirq context every jiffy
  */
-static inline void run_hrtimer_queue(struct hrtimer_cpu_base *cpu_base,
-				     int index)
+void hrtimer_run_queues(void)
 {
 	struct rb_node *node;
-	struct hrtimer_clock_base *base = &cpu_base->clock_base[index];
+	struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
+	struct hrtimer_clock_base *base;
+	int index, gettime = 1;
 
-	if (!base->first)
+	if (hrtimer_hres_active())
 		return;
 
-	if (base->get_softirq_time)
-		base->softirq_time = base->get_softirq_time();
-
-	spin_lock(&cpu_base->lock);
-
-	while ((node = base->first)) {
-		struct hrtimer *timer;
-
-		timer = rb_entry(node, struct hrtimer, node);
-		if (base->softirq_time.tv64 <= timer->expires.tv64)
-			break;
+	for (index = 0; index < HRTIMER_MAX_CLOCK_BASES; index++) {
+		base = &cpu_base->clock_base[index];
 
-		if (timer->cb_mode == HRTIMER_CB_SOFTIRQ) {
-			__remove_hrtimer(timer, base, HRTIMER_STATE_PENDING, 0);
-			list_add_tail(&timer->cb_entry,
-					&base->cpu_base->cb_pending);
+		if (!base->first)
 			continue;
+
+		if (base->get_softirq_time)
+			base->softirq_time = base->get_softirq_time();
+		else if (gettime) {
+			hrtimer_get_softirq_time(cpu_base);
+			gettime = 0;
 		}
 
-		__run_hrtimer(timer);
-	}
-	spin_unlock(&cpu_base->lock);
-}
+		spin_lock(&cpu_base->lock);
 
-void hrtimer_run_queues(void)
-{
-	struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
-	int i;
+		while ((node = base->first)) {
+			struct hrtimer *timer;
 
-	if (hrtimer_hres_active())
-		return;
+			timer = rb_entry(node, struct hrtimer, node);
+			if (base->softirq_time.tv64 <= timer->expires.tv64)
+				break;
 
-	hrtimer_get_softirq_time(cpu_base);
+			if (timer->cb_mode == HRTIMER_CB_SOFTIRQ) {
+				__remove_hrtimer(timer, base,
+					HRTIMER_STATE_PENDING, 0);
+				list_add_tail(&timer->cb_entry,
+					&base->cpu_base->cb_pending);
+				continue;
+			}
 
-	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++)
-		run_hrtimer_queue(cpu_base, i);
+			__run_hrtimer(timer);
+		}
+		spin_unlock(&cpu_base->lock);
+	}
 }
 
 /*
@@ -1424,7 +1449,6 @@ static void __cpuinit init_hrtimers_cpu(int cpu)
 	int i;
 
 	spin_lock_init(&cpu_base->lock);
-	lockdep_set_class(&cpu_base->lock, &cpu_base->lock_key);
 
 	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++)
 		cpu_base->clock_base[i].cpu_base = cpu_base;
@@ -1465,16 +1489,16 @@ static void migrate_hrtimers(int cpu)
 	tick_cancel_sched_timer(cpu);
 
 	local_irq_disable();
-	double_spin_lock(&new_base->lock, &old_base->lock,
-			 smp_processor_id() < cpu);
+	spin_lock(&new_base->lock);
+	spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING);
 
 	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
 		migrate_hrtimer_list(&old_base->clock_base[i],
 				     &new_base->clock_base[i]);
 	}
 
-	double_spin_unlock(&new_base->lock, &old_base->lock,
-			   smp_processor_id() < cpu);
+	spin_unlock(&old_base->lock);
+	spin_unlock(&new_base->lock);
 	local_irq_enable();
 	put_cpu_var(hrtimer_bases);
 }