2 files changed, 16 insertions, 17 deletions

diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index cf5cfdf8d613..abb674c9b764 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -49,8 +49,6 @@ struct hrtimer_base;
  * struct hrtimer - the basic hrtimer structure
  *
  * @node:       red black tree node for time ordered insertion
- * @list:       list head for easier access to the time ordered list,
- *              without walking the red black tree.
  * @expires:    the absolute expiry time in the hrtimers internal
  *              representation. The time is related to the clock on
  *              which the timer is based.
@@ -63,7 +61,6 @@ struct hrtimer_base;
  */
 struct hrtimer {
         struct rb_node          node;
-        struct list_head        list;
         ktime_t                 expires;
         enum hrtimer_state      state;
         int                     (*function)(void *);
@@ -78,7 +75,7 @@ struct hrtimer {
  *              to a base on another cpu.
  * @lock:       lock protecting the base and associated timers
  * @active:     red black tree root node for the active timers
- * @pending:    list of pending timers for simple time ordered access
+ * @first:      pointer to the timer node which expires first
  * @resolution: the resolution of the clock, in nanoseconds
  * @get_time:   function to retrieve the current time of the clock
  * @curr_timer: the timer which is executing a callback right now
@@ -87,7 +84,7 @@ struct hrtimer_base {
         clockid_t               index;
         spinlock_t              lock;
         struct rb_root          active;
-        struct list_head        pending;
+        struct rb_node          *first;
         unsigned long           resolution;
         ktime_t                 (*get_time)(void);
         struct hrtimer          *curr_timer;
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index f073a2461faa..e6e8278bcb18 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -314,7 +314,6 @@ 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 +329,23 @@ 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 +355,11 @@ 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);
 }
 
@@ -529,16 +531,17 @@ 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 +735,6 @@ 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++;
         }
 }