Merge branch 'tip/futex/devel' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-rt into core/futexes
futex,plist: Pass the real head of the priority list to plist_del() futex,plist: Remove debug lock assignment from plist_node plist: Shrink struct plist_head plist: Add priority list test
This commit is contained in:
Thomas Gleixner
Коммит
995612178c
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@ -31,15 +31,17 @@
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*
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* Simple ASCII art explanation:
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*
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* |HEAD |
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* | |
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* |prio_list.prev|<------------------------------------|
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* |prio_list.next|<->|pl|<->|pl|<--------------->|pl|<-|
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* |10 | |10| |21| |21| |21| |40| (prio)
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* | | | | | | | | | | | |
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* | | | | | | | | | | | |
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* |node_list.next|<->|nl|<->|nl|<->|nl|<->|nl|<->|nl|<-|
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* |node_list.prev|<------------------------------------|
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* pl:prio_list (only for plist_node)
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* nl:node_list
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* HEAD| NODE(S)
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* |
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* ||------------------------------------|
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* ||->|pl|<->|pl|<--------------->|pl|<-|
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* | |10| |21| |21| |21| |40| (prio)
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* | | | | | | | | | | |
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* | | | | | | | | | | |
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* |->|nl|<->|nl|<->|nl|<->|nl|<->|nl|<->|nl|<-|
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* |-------------------------------------------|
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*
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* The nodes on the prio_list list are sorted by priority to simplify
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* the insertion of new nodes. There are no nodes with duplicate
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@ -78,7 +80,6 @@
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#include <linux/spinlock_types.h>
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struct plist_head {
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struct list_head prio_list;
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struct list_head node_list;
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#ifdef CONFIG_DEBUG_PI_LIST
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raw_spinlock_t *rawlock;
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@ -88,7 +89,8 @@ struct plist_head {
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struct plist_node {
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int prio;
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struct plist_head plist;
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struct list_head prio_list;
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struct list_head node_list;
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};
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#ifdef CONFIG_DEBUG_PI_LIST
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@ -100,7 +102,6 @@ struct plist_node {
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#endif
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#define _PLIST_HEAD_INIT(head) \
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.prio_list = LIST_HEAD_INIT((head).prio_list), \
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.node_list = LIST_HEAD_INIT((head).node_list)
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/**
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@ -133,7 +134,8 @@ struct plist_node {
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#define PLIST_NODE_INIT(node, __prio) \
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{ \
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.prio = (__prio), \
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.plist = { _PLIST_HEAD_INIT((node).plist) }, \
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.prio_list = LIST_HEAD_INIT((node).prio_list), \
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.node_list = LIST_HEAD_INIT((node).node_list), \
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}
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/**
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@ -144,7 +146,6 @@ struct plist_node {
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static inline void
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plist_head_init(struct plist_head *head, spinlock_t *lock)
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{
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INIT_LIST_HEAD(&head->prio_list);
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INIT_LIST_HEAD(&head->node_list);
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#ifdef CONFIG_DEBUG_PI_LIST
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head->spinlock = lock;
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@ -160,7 +161,6 @@ plist_head_init(struct plist_head *head, spinlock_t *lock)
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static inline void
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plist_head_init_raw(struct plist_head *head, raw_spinlock_t *lock)
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{
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INIT_LIST_HEAD(&head->prio_list);
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INIT_LIST_HEAD(&head->node_list);
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#ifdef CONFIG_DEBUG_PI_LIST
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head->rawlock = lock;
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@ -176,7 +176,8 @@ plist_head_init_raw(struct plist_head *head, raw_spinlock_t *lock)
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static inline void plist_node_init(struct plist_node *node, int prio)
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{
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node->prio = prio;
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plist_head_init(&node->plist, NULL);
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INIT_LIST_HEAD(&node->prio_list);
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INIT_LIST_HEAD(&node->node_list);
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}
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extern void plist_add(struct plist_node *node, struct plist_head *head);
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@ -188,7 +189,7 @@ extern void plist_del(struct plist_node *node, struct plist_head *head);
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* @head: the head for your list
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*/
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#define plist_for_each(pos, head) \
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list_for_each_entry(pos, &(head)->node_list, plist.node_list)
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list_for_each_entry(pos, &(head)->node_list, node_list)
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/**
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* plist_for_each_safe - iterate safely over a plist of given type
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@ -199,7 +200,7 @@ extern void plist_del(struct plist_node *node, struct plist_head *head);
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* Iterate over a plist of given type, safe against removal of list entry.
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*/
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#define plist_for_each_safe(pos, n, head) \
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list_for_each_entry_safe(pos, n, &(head)->node_list, plist.node_list)
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list_for_each_entry_safe(pos, n, &(head)->node_list, node_list)
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/**
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* plist_for_each_entry - iterate over list of given type
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@ -208,7 +209,7 @@ extern void plist_del(struct plist_node *node, struct plist_head *head);
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* @mem: the name of the list_struct within the struct
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*/
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#define plist_for_each_entry(pos, head, mem) \
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list_for_each_entry(pos, &(head)->node_list, mem.plist.node_list)
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list_for_each_entry(pos, &(head)->node_list, mem.node_list)
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/**
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* plist_for_each_entry_safe - iterate safely over list of given type
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@ -220,7 +221,7 @@ extern void plist_del(struct plist_node *node, struct plist_head *head);
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* Iterate over list of given type, safe against removal of list entry.
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*/
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#define plist_for_each_entry_safe(pos, n, head, m) \
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list_for_each_entry_safe(pos, n, &(head)->node_list, m.plist.node_list)
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list_for_each_entry_safe(pos, n, &(head)->node_list, m.node_list)
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/**
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* plist_head_empty - return !0 if a plist_head is empty
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@ -237,7 +238,7 @@ static inline int plist_head_empty(const struct plist_head *head)
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*/
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static inline int plist_node_empty(const struct plist_node *node)
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{
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return plist_head_empty(&node->plist);
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return list_empty(&node->node_list);
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}
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/* All functions below assume the plist_head is not empty. */
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@ -285,7 +286,7 @@ static inline int plist_node_empty(const struct plist_node *node)
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static inline struct plist_node *plist_first(const struct plist_head *head)
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{
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return list_entry(head->node_list.next,
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struct plist_node, plist.node_list);
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struct plist_node, node_list);
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}
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/**
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@ -297,7 +298,7 @@ static inline struct plist_node *plist_first(const struct plist_head *head)
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static inline struct plist_node *plist_last(const struct plist_head *head)
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{
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return list_entry(head->node_list.prev,
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struct plist_node, plist.node_list);
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struct plist_node, node_list);
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}
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#endif
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@ -772,6 +772,24 @@ retry:
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return ret;
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}
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/**
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* __unqueue_futex() - Remove the futex_q from its futex_hash_bucket
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* @q: The futex_q to unqueue
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*
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* The q->lock_ptr must not be NULL and must be held by the caller.
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*/
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static void __unqueue_futex(struct futex_q *q)
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{
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struct futex_hash_bucket *hb;
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if (WARN_ON(!q->lock_ptr || !spin_is_locked(q->lock_ptr)
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|| plist_node_empty(&q->list)))
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return;
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hb = container_of(q->lock_ptr, struct futex_hash_bucket, lock);
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plist_del(&q->list, &hb->chain);
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}
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/*
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* The hash bucket lock must be held when this is called.
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* Afterwards, the futex_q must not be accessed.
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@ -789,7 +807,7 @@ static void wake_futex(struct futex_q *q)
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*/
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get_task_struct(p);
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plist_del(&q->list, &q->list.plist);
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__unqueue_futex(q);
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/*
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* The waiting task can free the futex_q as soon as
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* q->lock_ptr = NULL is written, without taking any locks. A
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@ -1064,9 +1082,6 @@ void requeue_futex(struct futex_q *q, struct futex_hash_bucket *hb1,
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plist_del(&q->list, &hb1->chain);
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plist_add(&q->list, &hb2->chain);
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q->lock_ptr = &hb2->lock;
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#ifdef CONFIG_DEBUG_PI_LIST
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q->list.plist.spinlock = &hb2->lock;
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#endif
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}
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get_futex_key_refs(key2);
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q->key = *key2;
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@ -1093,16 +1108,12 @@ void requeue_pi_wake_futex(struct futex_q *q, union futex_key *key,
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get_futex_key_refs(key);
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q->key = *key;
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WARN_ON(plist_node_empty(&q->list));
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plist_del(&q->list, &q->list.plist);
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__unqueue_futex(q);
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WARN_ON(!q->rt_waiter);
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q->rt_waiter = NULL;
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q->lock_ptr = &hb->lock;
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#ifdef CONFIG_DEBUG_PI_LIST
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q->list.plist.spinlock = &hb->lock;
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#endif
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wake_up_state(q->task, TASK_NORMAL);
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}
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@ -1450,9 +1461,6 @@ static inline void queue_me(struct futex_q *q, struct futex_hash_bucket *hb)
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prio = min(current->normal_prio, MAX_RT_PRIO);
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plist_node_init(&q->list, prio);
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#ifdef CONFIG_DEBUG_PI_LIST
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q->list.plist.spinlock = &hb->lock;
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#endif
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plist_add(&q->list, &hb->chain);
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q->task = current;
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spin_unlock(&hb->lock);
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@ -1497,8 +1505,7 @@ retry:
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spin_unlock(lock_ptr);
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goto retry;
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}
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WARN_ON(plist_node_empty(&q->list));
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plist_del(&q->list, &q->list.plist);
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__unqueue_futex(q);
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BUG_ON(q->pi_state);
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@ -1518,8 +1525,7 @@ retry:
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static void unqueue_me_pi(struct futex_q *q)
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__releases(q->lock_ptr)
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{
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WARN_ON(plist_node_empty(&q->list));
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plist_del(&q->list, &q->list.plist);
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__unqueue_futex(q);
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BUG_ON(!q->pi_state);
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free_pi_state(q->pi_state);
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@ -2156,7 +2162,7 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb,
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* We were woken prior to requeue by a timeout or a signal.
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* Unqueue the futex_q and determine which it was.
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*/
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plist_del(&q->list, &q->list.plist);
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plist_del(&q->list, &hb->chain);
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/* Handle spurious wakeups gracefully */
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ret = -EWOULDBLOCK;
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|
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135
lib/plist.c
135
lib/plist.c
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@ -28,6 +28,8 @@
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#ifdef CONFIG_DEBUG_PI_LIST
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static struct plist_head test_head;
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static void plist_check_prev_next(struct list_head *t, struct list_head *p,
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struct list_head *n)
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{
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@ -54,12 +56,13 @@ static void plist_check_list(struct list_head *top)
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static void plist_check_head(struct plist_head *head)
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{
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WARN_ON(!head->rawlock && !head->spinlock);
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WARN_ON(head != &test_head && !head->rawlock && !head->spinlock);
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if (head->rawlock)
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WARN_ON_SMP(!raw_spin_is_locked(head->rawlock));
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if (head->spinlock)
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WARN_ON_SMP(!spin_is_locked(head->spinlock));
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plist_check_list(&head->prio_list);
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if (!plist_head_empty(head))
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plist_check_list(&plist_first(head)->prio_list);
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plist_check_list(&head->node_list);
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}
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@ -75,25 +78,33 @@ static void plist_check_head(struct plist_head *head)
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*/
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void plist_add(struct plist_node *node, struct plist_head *head)
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{
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struct plist_node *iter;
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struct plist_node *first, *iter, *prev = NULL;
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struct list_head *node_next = &head->node_list;
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plist_check_head(head);
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WARN_ON(!plist_node_empty(node));
|
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WARN_ON(!list_empty(&node->prio_list));
|
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list_for_each_entry(iter, &head->prio_list, plist.prio_list) {
|
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if (node->prio < iter->prio)
|
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goto lt_prio;
|
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else if (node->prio == iter->prio) {
|
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iter = list_entry(iter->plist.prio_list.next,
|
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struct plist_node, plist.prio_list);
|
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goto eq_prio;
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if (plist_head_empty(head))
|
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goto ins_node;
|
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|
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first = iter = plist_first(head);
|
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|
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do {
|
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if (node->prio < iter->prio) {
|
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node_next = &iter->node_list;
|
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break;
|
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}
|
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}
|
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|
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lt_prio:
|
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list_add_tail(&node->plist.prio_list, &iter->plist.prio_list);
|
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eq_prio:
|
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list_add_tail(&node->plist.node_list, &iter->plist.node_list);
|
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prev = iter;
|
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iter = list_entry(iter->prio_list.next,
|
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struct plist_node, prio_list);
|
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} while (iter != first);
|
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|
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if (!prev || prev->prio != node->prio)
|
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list_add_tail(&node->prio_list, &iter->prio_list);
|
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ins_node:
|
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list_add_tail(&node->node_list, node_next);
|
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|
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plist_check_head(head);
|
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}
|
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|
|
@ -108,14 +119,98 @@ void plist_del(struct plist_node *node, struct plist_head *head)
|
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{
|
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plist_check_head(head);
|
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|
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if (!list_empty(&node->plist.prio_list)) {
|
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struct plist_node *next = plist_first(&node->plist);
|
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if (!list_empty(&node->prio_list)) {
|
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if (node->node_list.next != &head->node_list) {
|
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struct plist_node *next;
|
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|
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list_move_tail(&next->plist.prio_list, &node->plist.prio_list);
|
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list_del_init(&node->plist.prio_list);
|
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next = list_entry(node->node_list.next,
|
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struct plist_node, node_list);
|
||||
|
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/* add the next plist_node into prio_list */
|
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if (list_empty(&next->prio_list))
|
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list_add(&next->prio_list, &node->prio_list);
|
||||
}
|
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list_del_init(&node->prio_list);
|
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}
|
||||
|
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list_del_init(&node->plist.node_list);
|
||||
list_del_init(&node->node_list);
|
||||
|
||||
plist_check_head(head);
|
||||
}
|
||||
|
||||
#ifdef CONFIG_DEBUG_PI_LIST
|
||||
#include <linux/sched.h>
|
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#include <linux/module.h>
|
||||
#include <linux/init.h>
|
||||
|
||||
static struct plist_node __initdata test_node[241];
|
||||
|
||||
static void __init plist_test_check(int nr_expect)
|
||||
{
|
||||
struct plist_node *first, *prio_pos, *node_pos;
|
||||
|
||||
if (plist_head_empty(&test_head)) {
|
||||
BUG_ON(nr_expect != 0);
|
||||
return;
|
||||
}
|
||||
|
||||
prio_pos = first = plist_first(&test_head);
|
||||
plist_for_each(node_pos, &test_head) {
|
||||
if (nr_expect-- < 0)
|
||||
break;
|
||||
if (node_pos == first)
|
||||
continue;
|
||||
if (node_pos->prio == prio_pos->prio) {
|
||||
BUG_ON(!list_empty(&node_pos->prio_list));
|
||||
continue;
|
||||
}
|
||||
|
||||
BUG_ON(prio_pos->prio > node_pos->prio);
|
||||
BUG_ON(prio_pos->prio_list.next != &node_pos->prio_list);
|
||||
prio_pos = node_pos;
|
||||
}
|
||||
|
||||
BUG_ON(nr_expect != 0);
|
||||
BUG_ON(prio_pos->prio_list.next != &first->prio_list);
|
||||
}
|
||||
|
||||
static int __init plist_test(void)
|
||||
{
|
||||
int nr_expect = 0, i, loop;
|
||||
unsigned int r = local_clock();
|
||||
|
||||
printk(KERN_INFO "start plist test\n");
|
||||
plist_head_init(&test_head, NULL);
|
||||
for (i = 0; i < ARRAY_SIZE(test_node); i++)
|
||||
plist_node_init(test_node + i, 0);
|
||||
|
||||
for (loop = 0; loop < 1000; loop++) {
|
||||
r = r * 193939 % 47629;
|
||||
i = r % ARRAY_SIZE(test_node);
|
||||
if (plist_node_empty(test_node + i)) {
|
||||
r = r * 193939 % 47629;
|
||||
test_node[i].prio = r % 99;
|
||||
plist_add(test_node + i, &test_head);
|
||||
nr_expect++;
|
||||
} else {
|
||||
plist_del(test_node + i, &test_head);
|
||||
nr_expect--;
|
||||
}
|
||||
plist_test_check(nr_expect);
|
||||
}
|
||||
|
||||
for (i = 0; i < ARRAY_SIZE(test_node); i++) {
|
||||
if (plist_node_empty(test_node + i))
|
||||
continue;
|
||||
plist_del(test_node + i, &test_head);
|
||||
nr_expect--;
|
||||
plist_test_check(nr_expect);
|
||||
}
|
||||
|
||||
printk(KERN_INFO "end plist test\n");
|
||||
return 0;
|
||||
}
|
||||
|
||||
module_init(plist_test);
|
||||
|
||||
#endif
|
||||
|
|
|
|||
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Ссылка в новой задаче