diff options
Diffstat (limited to 'include/linux/rculist.h')
| -rw-r--r-- | include/linux/rculist.h | 64 |
1 files changed, 46 insertions, 18 deletions
diff --git a/include/linux/rculist.h b/include/linux/rculist.h index 127f534fec94..e91ec9ddcd30 100644 --- a/include/linux/rculist.h +++ b/include/linux/rculist.h @@ -182,7 +182,7 @@ static inline void list_replace_rcu(struct list_head *old, * @list: the RCU-protected list to splice * @prev: points to the last element of the existing list * @next: points to the first element of the existing list - * @sync: function to sync: synchronize_rcu(), synchronize_sched(), ... + * @sync: synchronize_rcu, synchronize_rcu_expedited, ... * * The list pointed to by @prev and @next can be RCU-read traversed * concurrently with this function. @@ -240,7 +240,7 @@ static inline void __list_splice_init_rcu(struct list_head *list, * designed for stacks. * @list: the RCU-protected list to splice * @head: the place in the existing list to splice the first list into - * @sync: function to sync: synchronize_rcu(), synchronize_sched(), ... + * @sync: synchronize_rcu, synchronize_rcu_expedited, ... */ static inline void list_splice_init_rcu(struct list_head *list, struct list_head *head, @@ -255,7 +255,7 @@ static inline void list_splice_init_rcu(struct list_head *list, * list, designed for queues. * @list: the RCU-protected list to splice * @head: the place in the existing list to splice the first list into - * @sync: function to sync: synchronize_rcu(), synchronize_sched(), ... + * @sync: synchronize_rcu, synchronize_rcu_expedited, ... */ static inline void list_splice_tail_init_rcu(struct list_head *list, struct list_head *head, @@ -359,13 +359,12 @@ static inline void list_splice_tail_init_rcu(struct list_head *list, * @type: the type of the struct this is embedded in. * @member: the name of the list_head within the struct. * - * This primitive may safely run concurrently with the _rcu list-mutation - * primitives such as list_add_rcu(), but requires some implicit RCU - * read-side guarding. One example is running within a special - * exception-time environment where preemption is disabled and where - * lockdep cannot be invoked (in which case updaters must use RCU-sched, - * as in synchronize_sched(), call_rcu_sched(), and friends). Another - * example is when items are added to the list, but never deleted. + * This primitive may safely run concurrently with the _rcu + * list-mutation primitives such as list_add_rcu(), but requires some + * implicit RCU read-side guarding. One example is running within a special + * exception-time environment where preemption is disabled and where lockdep + * cannot be invoked. Another example is when items are added to the list, + * but never deleted. */ #define list_entry_lockless(ptr, type, member) \ container_of((typeof(ptr))READ_ONCE(ptr), type, member) @@ -376,13 +375,12 @@ static inline void list_splice_tail_init_rcu(struct list_head *list, * @head: the head for your list. * @member: the name of the list_struct within the struct. * - * This primitive may safely run concurrently with the _rcu list-mutation - * primitives such as list_add_rcu(), but requires some implicit RCU - * read-side guarding. One example is running within a special - * exception-time environment where preemption is disabled and where - * lockdep cannot be invoked (in which case updaters must use RCU-sched, - * as in synchronize_sched(), call_rcu_sched(), and friends). Another - * example is when items are added to the list, but never deleted. + * This primitive may safely run concurrently with the _rcu + * list-mutation primitives such as list_add_rcu(), but requires some + * implicit RCU read-side guarding. One example is running within a special + * exception-time environment where preemption is disabled and where lockdep + * cannot be invoked. Another example is when items are added to the list, + * but never deleted. */ #define list_for_each_entry_lockless(pos, head, member) \ for (pos = list_entry_lockless((head)->next, typeof(*pos), member); \ @@ -396,7 +394,16 @@ static inline void list_splice_tail_init_rcu(struct list_head *list, * @member: the name of the list_head within the struct. * * Continue to iterate over list of given type, continuing after - * the current position. + * the current position which must have been in the list when the RCU read + * lock was taken. + * This would typically require either that you obtained the node from a + * previous walk of the list in the same RCU read-side critical section, or + * that you held some sort of non-RCU reference (such as a reference count) + * to keep the node alive *and* in the list. + * + * This iterator is similar to list_for_each_entry_from_rcu() except + * this starts after the given position and that one starts at the given + * position. */ #define list_for_each_entry_continue_rcu(pos, head, member) \ for (pos = list_entry_rcu(pos->member.next, typeof(*pos), member); \ @@ -404,6 +411,27 @@ static inline void list_splice_tail_init_rcu(struct list_head *list, pos = list_entry_rcu(pos->member.next, typeof(*pos), member)) /** + * list_for_each_entry_from_rcu - iterate over a list from current point + * @pos: the type * to use as a loop cursor. + * @head: the head for your list. + * @member: the name of the list_node within the struct. + * + * Iterate over the tail of a list starting from a given position, + * which must have been in the list when the RCU read lock was taken. + * This would typically require either that you obtained the node from a + * previous walk of the list in the same RCU read-side critical section, or + * that you held some sort of non-RCU reference (such as a reference count) + * to keep the node alive *and* in the list. + * + * This iterator is similar to list_for_each_entry_continue_rcu() except + * this starts from the given position and that one starts from the position + * after the given position. + */ +#define list_for_each_entry_from_rcu(pos, head, member) \ + for (; &(pos)->member != (head); \ + pos = list_entry_rcu(pos->member.next, typeof(*(pos)), member)) + +/** * hlist_del_rcu - deletes entry from hash list without re-initialization * @n: the element to delete from the hash list. * |