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![Thomas Gleixner](/assets/img/avatar_default.png)
Using a linear O(N) search for timer insertion affects execution time and D-cache footprint badly with a larger number of timers. Switch the storage to a timerqueue which is already used for hrtimers and alarmtimers. It does not affect the size of struct k_itimer as it.alarm is still larger. The extra list head for the expiry list will go away later once the expiry is moved into task work context. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1908272129220.1939@nanos.tec.linutronix.de
60 lines
1.4 KiB
C
60 lines
1.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_TIMERQUEUE_H
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#define _LINUX_TIMERQUEUE_H
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#include <linux/rbtree.h>
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#include <linux/ktime.h>
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struct timerqueue_node {
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struct rb_node node;
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ktime_t expires;
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};
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struct timerqueue_head {
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struct rb_root_cached rb_root;
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};
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extern bool timerqueue_add(struct timerqueue_head *head,
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struct timerqueue_node *node);
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extern bool timerqueue_del(struct timerqueue_head *head,
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struct timerqueue_node *node);
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extern struct timerqueue_node *timerqueue_iterate_next(
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struct timerqueue_node *node);
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/**
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* timerqueue_getnext - Returns the timer with the earliest expiration time
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*
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* @head: head of timerqueue
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*
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* Returns a pointer to the timer node that has the earliest expiration time.
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*/
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static inline
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struct timerqueue_node *timerqueue_getnext(struct timerqueue_head *head)
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{
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struct rb_node *leftmost = rb_first_cached(&head->rb_root);
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return rb_entry(leftmost, struct timerqueue_node, node);
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}
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static inline void timerqueue_init(struct timerqueue_node *node)
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{
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RB_CLEAR_NODE(&node->node);
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}
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static inline bool timerqueue_node_queued(struct timerqueue_node *node)
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{
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return !RB_EMPTY_NODE(&node->node);
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}
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static inline bool timerqueue_node_expires(struct timerqueue_node *node)
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{
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return node->expires;
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}
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static inline void timerqueue_init_head(struct timerqueue_head *head)
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{
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head->rb_root = RB_ROOT_CACHED;
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}
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#endif /* _LINUX_TIMERQUEUE_H */
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