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-rw-r--r--include/linux/hrtimer.h7
-rw-r--r--kernel/hrtimer.c26
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++;
}
}