hrtimer: Use linked timerqueue

To prepare for optimizing the rearming of enqueued timers, switch to the
linked timerqueue. That allows to check whether the new expiry time changes
the position of the timer in the RB tree or not, by checking the new expiry
time against the previous and the next timers expiry.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260224163431.806643179@kernel.org

1 files changed, 17 insertions, 17 deletions

diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index d1e58482e0a9..5e45982363ce 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -557,10 +557,10 @@ static ktime_t hrtimer_bases_next_event_without(struct hrtimer_cpu_base *cpu_bas
 		 * If the excluded timer is the first on this base evaluate the
 		 * next timer.
 		 */
-		struct timerqueue_node *node = timerqueue_getnext(&base->active);
+		struct timerqueue_linked_node *node = timerqueue_linked_first(&base->active);
 
 		if (unlikely(&exclude->node == node)) {
-			node = timerqueue_iterate_next(node);
+			node = timerqueue_linked_next(node);
 			if (!node)
 				continue;
 			expires = ktime_sub(node->expires, base->offset);
@@ -576,7 +576,7 @@ static ktime_t hrtimer_bases_next_event_without(struct hrtimer_cpu_base *cpu_bas
 
 static __always_inline struct hrtimer *clock_base_next_timer(struct hrtimer_clock_base *base)
 {
-	struct timerqueue_node *next = timerqueue_getnext(&base->active);
+	struct timerqueue_linked_node *next = timerqueue_linked_first(&base->active);
 
 	return container_of(next, struct hrtimer, node);
 }
@@ -938,9 +938,9 @@ static bool update_needs_ipi(struct hrtimer_cpu_base *cpu_base, unsigned int act
 	active &= cpu_base->active_bases;
 
 	for_each_active_base(base, cpu_base, active) {
-		struct timerqueue_node *next;
+		struct timerqueue_linked_node *next;
 
-		next = timerqueue_getnext(&base->active);
+		next = timerqueue_linked_first(&base->active);
 		expires = ktime_sub(next->expires, base->offset);
 		if (expires < cpu_base->expires_next)
 			return true;
@@ -1112,7 +1112,7 @@ static bool enqueue_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *ba
 	/* Pairs with the lockless read in hrtimer_is_queued() */
 	WRITE_ONCE(timer->is_queued, HRTIMER_STATE_ENQUEUED);
 
-	if (!timerqueue_add(&base->active, &timer->node))
+	if (!timerqueue_linked_add(&base->active, &timer->node))
 		return false;
 
 	base->expires_next = hrtimer_get_expires(timer);
@@ -1121,7 +1121,7 @@ static bool enqueue_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *ba
 
 static inline void base_update_next_timer(struct hrtimer_clock_base *base)
 {
-	struct timerqueue_node *next = timerqueue_getnext(&base->active);
+	struct timerqueue_linked_node *next = timerqueue_linked_first(&base->active);
 
 	base->expires_next = next ? next->expires : KTIME_MAX;
 }
@@ -1148,9 +1148,9 @@ static void __remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *b
 	/* Pairs with the lockless read in hrtimer_is_queued() */
 	WRITE_ONCE(timer->is_queued, newstate);
 
-	was_first = &timer->node == timerqueue_getnext(&base->active);
+	was_first = !timerqueue_linked_prev(&timer->node);
 
-	if (!timerqueue_del(&base->active, &timer->node))
+	if (!timerqueue_linked_del(&base->active, &timer->node))
 		cpu_base->active_bases &= ~(1 << base->index);
 
 	/* Nothing to update if this was not the first timer in the base */
@@ -1212,8 +1212,8 @@ remove_and_enqueue_same_base(struct hrtimer *timer, struct hrtimer_clock_base *b
 	/* Remove it from the timer queue if active */
 	if (timer->is_queued) {
 		debug_hrtimer_deactivate(timer);
-		was_first = &timer->node == timerqueue_getnext(&base->active);
-		timerqueue_del(&base->active, &timer->node);
+		was_first = !timerqueue_linked_prev(&timer->node);
+		timerqueue_linked_del(&base->active, &timer->node);
 	}
 
 	/* Set the new expiry time */
@@ -1226,7 +1226,7 @@ remove_and_enqueue_same_base(struct hrtimer *timer, struct hrtimer_clock_base *b
 	WRITE_ONCE(timer->is_queued, HRTIMER_STATE_ENQUEUED);
 
 	/* If it's the first expiring timer now or again, update base */
-	if (timerqueue_add(&base->active, &timer->node)) {
+	if (timerqueue_linked_add(&base->active, &timer->node)) {
 		base->expires_next = expires;
 		return true;
 	}
@@ -1758,7 +1758,7 @@ static void __hrtimer_setup(struct hrtimer *timer, enum hrtimer_restart (*fn)(st
 	timer->is_hard = !!(mode & HRTIMER_MODE_HARD);
 	timer->is_lazy = !!(mode & HRTIMER_MODE_LAZY_REARM);
 	timer->base = &cpu_base->clock_base[base];
-	timerqueue_init(&timer->node);
+	timerqueue_linked_init(&timer->node);
 
 	if (WARN_ON_ONCE(!fn))
 		ACCESS_PRIVATE(timer, function) = hrtimer_dummy_timeout;
@@ -1923,7 +1923,7 @@ static void __run_hrtimer(struct hrtimer_cpu_base *cpu_base, struct hrtimer_cloc
 
 static __always_inline struct hrtimer *clock_base_next_timer_safe(struct hrtimer_clock_base *base)
 {
-	struct timerqueue_node *next = timerqueue_getnext(&base->active);
+	struct timerqueue_linked_node *next = timerqueue_linked_first(&base->active);
 
 	return next ? container_of(next, struct hrtimer, node) : NULL;
 }
@@ -2369,7 +2369,7 @@ int hrtimers_prepare_cpu(unsigned int cpu)
 
 		clock_b->cpu_base = cpu_base;
 		seqcount_raw_spinlock_init(&clock_b->seq, &cpu_base->lock);
-		timerqueue_init_head(&clock_b->active);
+		timerqueue_linked_init_head(&clock_b->active);
 	}
 
 	cpu_base->cpu = cpu;
@@ -2399,10 +2399,10 @@ int hrtimers_cpu_starting(unsigned int cpu)
 static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
 				struct hrtimer_clock_base *new_base)
 {
-	struct timerqueue_node *node;
+	struct timerqueue_linked_node *node;
 	struct hrtimer *timer;
 
-	while ((node = timerqueue_getnext(&old_base->active))) {
+	while ((node = timerqueue_linked_first(&old_base->active))) {
 		timer = container_of(node, struct hrtimer, node);
 		BUG_ON(hrtimer_callback_running(timer));
 		debug_hrtimer_deactivate(timer);