1 files changed, 19 insertions, 15 deletions

diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index f073a2461faa..04ccab099e84 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -275,7 +275,7 @@ void unlock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags)
  * The number of overruns is added to the overrun field.
  */
 unsigned long
-hrtimer_forward(struct hrtimer *timer, const ktime_t interval)
+hrtimer_forward(struct hrtimer *timer, ktime_t interval)
 {
         unsigned long orun = 1;
         ktime_t delta, now;
@@ -287,6 +287,9 @@ hrtimer_forward(struct hrtimer *timer, const ktime_t interval)
         if (delta.tv64 < 0)
                 return 0;
 
+        if (interval.tv64 < timer->base->resolution.tv64)
+                interval.tv64 = timer->base->resolution.tv64;
+
         if (unlikely(delta.tv64 >= interval.tv64)) {
                 nsec_t incr = ktime_to_ns(interval);
 
@@ -314,7 +317,6 @@ hrtimer_forward(struct hrtimer *timer, const ktime_t interval)
 static void enqueue_hrtimer(struct hrtimer *timer, struct hrtimer_base *base)
 {
         struct rb_node **link = &base->active.rb_node;
-        struct list_head *prev = &base->pending;
         struct rb_node *parent = NULL;
         struct hrtimer *entry;
 
@@ -330,22 +332,23 @@ static void enqueue_hrtimer(struct hrtimer *timer, struct hrtimer_base *base)
                  */
                 if (timer->expires.tv64 < entry->expires.tv64)
                         link = &(*link)->rb_left;
-                else {
+                else
                         link = &(*link)->rb_right;
-                        prev = &entry->list;
-                }
         }
 
         /*
-         * Insert the timer to the rbtree and to the sorted list:
+         * Insert the timer to the rbtree and check whether it
+         * replaces the first pending timer
          */
         rb_link_node(&timer->node, parent, link);
         rb_insert_color(&timer->node, &base->active);
-        list_add(&timer->list, prev);
 
         timer->state = HRTIMER_PENDING;
-}
 
+        if (!base->first || timer->expires.tv64 <
+            rb_entry(base->first, struct hrtimer, node)->expires.tv64)
+                base->first = &timer->node;
+}
 
 /*
  * __remove_hrtimer - internal function to remove a timer
@@ -355,9 +358,11 @@ static void enqueue_hrtimer(struct hrtimer *timer, struct hrtimer_base *base)
 static void __remove_hrtimer(struct hrtimer *timer, struct hrtimer_base *base)
 {
         /*
-         * Remove the timer from the sorted list and from the rbtree:
+         * Remove the timer from the rbtree and replace the
+         * first entry pointer if necessary.
          */
-        list_del(&timer->list);
+        if (base->first == &timer->node)
+                base->first = rb_next(&timer->node);
         rb_erase(&timer->node, &base->active);
 }
 
@@ -516,9 +521,8 @@ int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp)
 {
         struct hrtimer_base *bases;
 
-        tp->tv_sec = 0;
         bases = per_cpu(hrtimer_bases, raw_smp_processor_id());
-        tp->tv_nsec = bases[which_clock].resolution;
+        *tp = ktime_to_timespec(bases[which_clock].resolution);
 
         return 0;
 }
@@ -529,16 +533,17 @@ int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp)
 static inline void run_hrtimer_queue(struct hrtimer_base *base)
 {
         ktime_t now = base->get_time();
+        struct rb_node *node;
 
         spin_lock_irq(&base->lock);
 
-        while (!list_empty(&base->pending)) {
+        while ((node = base->first)) {
                 struct hrtimer *timer;
                 int (*fn)(void *);
                 int restart;
                 void *data;
 
-                timer = list_entry(base->pending.next, struct hrtimer, list);
+                timer = rb_entry(node, struct hrtimer, node);
                 if (now.tv64 <= timer->expires.tv64)
                         break;
 
@@ -732,7 +737,6 @@ static void __devinit init_hrtimers_cpu(int cpu)
 
         for (i = 0; i < MAX_HRTIMER_BASES; i++) {
                 spin_lock_init(&base->lock);
-                INIT_LIST_HEAD(&base->pending);
                 base++;
         }
 }