diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index cf5cfdf8d61304b319486724f9e0ec7515b63148..abb674c9b76465be8638acba950adcd90a21bea3 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 f073a2461faa0b2090c4094215aa9d7804882eae..e6e8278bcb18173f137b08d8602b7eb183b9d558 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++; } }