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authorFranck Bui-Huu <fbuihuu@gmail.com>2008-05-12 21:21:05 +0200
committerIngo Molnar <mingo@elte.hu>2008-05-19 10:01:37 +0200
commit82524746c27fa418c250a56dd7606b9d3fc79826 (patch)
tree1801230b8fc2e436e722ac6f54fc53f1c112c310 /include/linux/list.h
parent32300751b4079cb5688453baa94711579d4285d5 (diff)
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rcu: split list.h and move rcu-protected lists into rculist.h
Move rcu-protected lists from list.h into a new header file rculist.h. This is done because list are a very used primitive structure all over the kernel and it's currently impossible to include other header files in this list.h without creating some circular dependencies. For example, list.h implements rcu-protected list and uses rcu_dereference() without including rcupdate.h. It actually compiles because users of rcu_dereference() are macros. Others RCU functions could be used too but aren't probably because of this. Therefore this patch creates rculist.h which includes rcupdates without to many changes/troubles. Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Josh Triplett <josh@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux/list.h')
-rw-r--r--include/linux/list.h367
1 files changed, 0 insertions, 367 deletions
diff --git a/include/linux/list.h b/include/linux/list.h
index 08cf4f651889..139ec41d9c2e 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -85,65 +85,6 @@ static inline void list_add_tail(struct list_head *new, struct list_head *head)
}
/*
- * Insert a new entry between two known consecutive entries.
- *
- * This is only for internal list manipulation where we know
- * the prev/next entries already!
- */
-static inline void __list_add_rcu(struct list_head * new,
- struct list_head * prev, struct list_head * next)
-{
- new->next = next;
- new->prev = prev;
- smp_wmb();
- next->prev = new;
- prev->next = new;
-}
-
-/**
- * list_add_rcu - add a new entry to rcu-protected list
- * @new: new entry to be added
- * @head: list head to add it after
- *
- * Insert a new entry after the specified head.
- * This is good for implementing stacks.
- *
- * The caller must take whatever precautions are necessary
- * (such as holding appropriate locks) to avoid racing
- * with another list-mutation primitive, such as list_add_rcu()
- * or list_del_rcu(), running on this same list.
- * However, it is perfectly legal to run concurrently with
- * the _rcu list-traversal primitives, such as
- * list_for_each_entry_rcu().
- */
-static inline void list_add_rcu(struct list_head *new, struct list_head *head)
-{
- __list_add_rcu(new, head, head->next);
-}
-
-/**
- * list_add_tail_rcu - add a new entry to rcu-protected list
- * @new: new entry to be added
- * @head: list head to add it before
- *
- * Insert a new entry before the specified head.
- * This is useful for implementing queues.
- *
- * The caller must take whatever precautions are necessary
- * (such as holding appropriate locks) to avoid racing
- * with another list-mutation primitive, such as list_add_tail_rcu()
- * or list_del_rcu(), running on this same list.
- * However, it is perfectly legal to run concurrently with
- * the _rcu list-traversal primitives, such as
- * list_for_each_entry_rcu().
- */
-static inline void list_add_tail_rcu(struct list_head *new,
- struct list_head *head)
-{
- __list_add_rcu(new, head->prev, head);
-}
-
-/*
* Delete a list entry by making the prev/next entries
* point to each other.
*
@@ -174,36 +115,6 @@ extern void list_del(struct list_head *entry);
#endif
/**
- * list_del_rcu - deletes entry from list without re-initialization
- * @entry: the element to delete from the list.
- *
- * Note: list_empty() on entry does not return true after this,
- * the entry is in an undefined state. It is useful for RCU based
- * lockfree traversal.
- *
- * In particular, it means that we can not poison the forward
- * pointers that may still be used for walking the list.
- *
- * The caller must take whatever precautions are necessary
- * (such as holding appropriate locks) to avoid racing
- * with another list-mutation primitive, such as list_del_rcu()
- * or list_add_rcu(), running on this same list.
- * However, it is perfectly legal to run concurrently with
- * the _rcu list-traversal primitives, such as
- * list_for_each_entry_rcu().
- *
- * Note that the caller is not permitted to immediately free
- * the newly deleted entry. Instead, either synchronize_rcu()
- * or call_rcu() must be used to defer freeing until an RCU
- * grace period has elapsed.
- */
-static inline void list_del_rcu(struct list_head *entry)
-{
- __list_del(entry->prev, entry->next);
- entry->prev = LIST_POISON2;
-}
-
-/**
* list_replace - replace old entry by new one
* @old : the element to be replaced
* @new : the new element to insert
@@ -227,25 +138,6 @@ static inline void list_replace_init(struct list_head *old,
}
/**
- * list_replace_rcu - replace old entry by new one
- * @old : the element to be replaced
- * @new : the new element to insert
- *
- * The @old entry will be replaced with the @new entry atomically.
- * Note: @old should not be empty.
- */
-static inline void list_replace_rcu(struct list_head *old,
- struct list_head *new)
-{
- new->next = old->next;
- new->prev = old->prev;
- smp_wmb();
- new->next->prev = new;
- new->prev->next = new;
- old->prev = LIST_POISON2;
-}
-
-/**
* list_del_init - deletes entry from list and reinitialize it.
* @entry: the element to delete from the list.
*/
@@ -369,62 +261,6 @@ static inline void list_splice_init(struct list_head *list,
}
/**
- * list_splice_init_rcu - splice an RCU-protected list into an existing list.
- * @list: the RCU-protected list to splice
- * @head: the place in the list to splice the first list into
- * @sync: function to sync: synchronize_rcu(), synchronize_sched(), ...
- *
- * @head can be RCU-read traversed concurrently with this function.
- *
- * Note that this function blocks.
- *
- * Important note: the caller must take whatever action is necessary to
- * prevent any other updates to @head. In principle, it is possible
- * to modify the list as soon as sync() begins execution.
- * If this sort of thing becomes necessary, an alternative version
- * based on call_rcu() could be created. But only if -really-
- * needed -- there is no shortage of RCU API members.
- */
-static inline void list_splice_init_rcu(struct list_head *list,
- struct list_head *head,
- void (*sync)(void))
-{
- struct list_head *first = list->next;
- struct list_head *last = list->prev;
- struct list_head *at = head->next;
-
- if (list_empty(head))
- return;
-
- /* "first" and "last" tracking list, so initialize it. */
-
- INIT_LIST_HEAD(list);
-
- /*
- * At this point, the list body still points to the source list.
- * Wait for any readers to finish using the list before splicing
- * the list body into the new list. Any new readers will see
- * an empty list.
- */
-
- sync();
-
- /*
- * Readers are finished with the source list, so perform splice.
- * The order is important if the new list is global and accessible
- * to concurrent RCU readers. Note that RCU readers are not
- * permitted to traverse the prev pointers without excluding
- * this function.
- */
-
- last->next = at;
- smp_wmb();
- head->next = first;
- first->prev = head;
- at->prev = last;
-}
-
-/**
* list_entry - get the struct for this entry
* @ptr: the &struct list_head pointer.
* @type: the type of the struct this is embedded in.
@@ -629,57 +465,6 @@ static inline void list_splice_init_rcu(struct list_head *list,
&pos->member != (head); \
pos = n, n = list_entry(n->member.prev, typeof(*n), member))
-/**
- * list_for_each_rcu - iterate over an rcu-protected list
- * @pos: the &struct list_head to use as a loop cursor.
- * @head: the head for your list.
- *
- * This list-traversal primitive may safely run concurrently with
- * the _rcu list-mutation primitives such as list_add_rcu()
- * as long as the traversal is guarded by rcu_read_lock().
- */
-#define list_for_each_rcu(pos, head) \
- for (pos = rcu_dereference((head)->next); \
- prefetch(pos->next), pos != (head); \
- pos = rcu_dereference(pos->next))
-
-#define __list_for_each_rcu(pos, head) \
- for (pos = rcu_dereference((head)->next); \
- pos != (head); \
- pos = rcu_dereference(pos->next))
-
-/**
- * list_for_each_entry_rcu - iterate over rcu list of given type
- * @pos: the type * to use as a loop cursor.
- * @head: the head for your list.
- * @member: the name of the list_struct within the struct.
- *
- * This list-traversal primitive may safely run concurrently with
- * the _rcu list-mutation primitives such as list_add_rcu()
- * as long as the traversal is guarded by rcu_read_lock().
- */
-#define list_for_each_entry_rcu(pos, head, member) \
- for (pos = list_entry(rcu_dereference((head)->next), typeof(*pos), member); \
- prefetch(pos->member.next), &pos->member != (head); \
- pos = list_entry(rcu_dereference(pos->member.next), typeof(*pos), member))
-
-
-/**
- * list_for_each_continue_rcu
- * @pos: the &struct list_head to use as a loop cursor.
- * @head: the head for your list.
- *
- * Iterate over an rcu-protected list, continuing after current point.
- *
- * This list-traversal primitive may safely run concurrently with
- * the _rcu list-mutation primitives such as list_add_rcu()
- * as long as the traversal is guarded by rcu_read_lock().
- */
-#define list_for_each_continue_rcu(pos, head) \
- for ((pos) = rcu_dereference((pos)->next); \
- prefetch((pos)->next), (pos) != (head); \
- (pos) = rcu_dereference((pos)->next))
-
/*
* Double linked lists with a single pointer list head.
* Mostly useful for hash tables where the two pointer list head is
@@ -730,31 +515,6 @@ static inline void hlist_del(struct hlist_node *n)
n->pprev = LIST_POISON2;
}
-/**
- * hlist_del_rcu - deletes entry from hash list without re-initialization
- * @n: the element to delete from the hash list.
- *
- * Note: list_unhashed() on entry does not return true after this,
- * the entry is in an undefined state. It is useful for RCU based
- * lockfree traversal.
- *
- * In particular, it means that we can not poison the forward
- * pointers that may still be used for walking the hash list.
- *
- * The caller must take whatever precautions are necessary
- * (such as holding appropriate locks) to avoid racing
- * with another list-mutation primitive, such as hlist_add_head_rcu()
- * or hlist_del_rcu(), running on this same list.
- * However, it is perfectly legal to run concurrently with
- * the _rcu list-traversal primitives, such as
- * hlist_for_each_entry().
- */
-static inline void hlist_del_rcu(struct hlist_node *n)
-{
- __hlist_del(n);
- n->pprev = LIST_POISON2;
-}
-
static inline void hlist_del_init(struct hlist_node *n)
{
if (!hlist_unhashed(n)) {
@@ -763,27 +523,6 @@ static inline void hlist_del_init(struct hlist_node *n)
}
}
-/**
- * hlist_replace_rcu - replace old entry by new one
- * @old : the element to be replaced
- * @new : the new element to insert
- *
- * The @old entry will be replaced with the @new entry atomically.
- */
-static inline void hlist_replace_rcu(struct hlist_node *old,
- struct hlist_node *new)
-{
- struct hlist_node *next = old->next;
-
- new->next = next;
- new->pprev = old->pprev;
- smp_wmb();
- if (next)
- new->next->pprev = &new->next;
- *new->pprev = new;
- old->pprev = LIST_POISON2;
-}
-
static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
{
struct hlist_node *first = h->first;
@@ -794,38 +533,6 @@ static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
n->pprev = &h->first;
}
-
-/**
- * hlist_add_head_rcu
- * @n: the element to add to the hash list.
- * @h: the list to add to.
- *
- * Description:
- * Adds the specified element to the specified hlist,
- * while permitting racing traversals.
- *
- * The caller must take whatever precautions are necessary
- * (such as holding appropriate locks) to avoid racing
- * with another list-mutation primitive, such as hlist_add_head_rcu()
- * or hlist_del_rcu(), running on this same list.
- * However, it is perfectly legal to run concurrently with
- * the _rcu list-traversal primitives, such as
- * hlist_for_each_entry_rcu(), used to prevent memory-consistency
- * problems on Alpha CPUs. Regardless of the type of CPU, the
- * list-traversal primitive must be guarded by rcu_read_lock().
- */
-static inline void hlist_add_head_rcu(struct hlist_node *n,
- struct hlist_head *h)
-{
- struct hlist_node *first = h->first;
- n->next = first;
- n->pprev = &h->first;
- smp_wmb();
- if (first)
- first->pprev = &n->next;
- h->first = n;
-}
-
/* next must be != NULL */
static inline void hlist_add_before(struct hlist_node *n,
struct hlist_node *next)
@@ -847,63 +554,6 @@ static inline void hlist_add_after(struct hlist_node *n,
next->next->pprev = &next->next;
}
-/**
- * hlist_add_before_rcu
- * @n: the new element to add to the hash list.
- * @next: the existing element to add the new element before.
- *
- * Description:
- * Adds the specified element to the specified hlist
- * before the specified node while permitting racing traversals.
- *
- * The caller must take whatever precautions are necessary
- * (such as holding appropriate locks) to avoid racing
- * with another list-mutation primitive, such as hlist_add_head_rcu()
- * or hlist_del_rcu(), running on this same list.
- * However, it is perfectly legal to run concurrently with
- * the _rcu list-traversal primitives, such as
- * hlist_for_each_entry_rcu(), used to prevent memory-consistency
- * problems on Alpha CPUs.
- */
-static inline void hlist_add_before_rcu(struct hlist_node *n,
- struct hlist_node *next)
-{
- n->pprev = next->pprev;
- n->next = next;
- smp_wmb();
- next->pprev = &n->next;
- *(n->pprev) = n;
-}
-
-/**
- * hlist_add_after_rcu
- * @prev: the existing element to add the new element after.
- * @n: the new element to add to the hash list.
- *
- * Description:
- * Adds the specified element to the specified hlist
- * after the specified node while permitting racing traversals.
- *
- * The caller must take whatever precautions are necessary
- * (such as holding appropriate locks) to avoid racing
- * with another list-mutation primitive, such as hlist_add_head_rcu()
- * or hlist_del_rcu(), running on this same list.
- * However, it is perfectly legal to run concurrently with
- * the _rcu list-traversal primitives, such as
- * hlist_for_each_entry_rcu(), used to prevent memory-consistency
- * problems on Alpha CPUs.
- */
-static inline void hlist_add_after_rcu(struct hlist_node *prev,
- struct hlist_node *n)
-{
- n->next = prev->next;
- n->pprev = &prev->next;
- smp_wmb();
- prev->next = n;
- if (n->next)
- n->next->pprev = &n->next;
-}
-
#define hlist_entry(ptr, type, member) container_of(ptr,type,member)
#define hlist_for_each(pos, head) \
@@ -964,21 +614,4 @@ static inline void hlist_add_after_rcu(struct hlist_node *prev,
({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
pos = n)
-/**
- * hlist_for_each_entry_rcu - iterate over rcu list of given type
- * @tpos: the type * to use as a loop cursor.
- * @pos: the &struct hlist_node to use as a loop cursor.
- * @head: the head for your list.
- * @member: the name of the hlist_node within the struct.
- *
- * This list-traversal primitive may safely run concurrently with
- * the _rcu list-mutation primitives such as hlist_add_head_rcu()
- * as long as the traversal is guarded by rcu_read_lock().
- */
-#define hlist_for_each_entry_rcu(tpos, pos, head, member) \
- for (pos = rcu_dereference((head)->first); \
- pos && ({ prefetch(pos->next); 1;}) && \
- ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
- pos = rcu_dereference(pos->next))
-
#endif