From: Oleg Nesterov list_replace() is similar to list_replace_rcu(), but unlike list_replace_rcu() it could be used when list_empty(old) == 1 doesn't use barriers Signed-off-by: Oleg Nesterov Signed-off-by: Andrew Morton --- include/linux/list.h | 23 +++++++++++++++++++++++ 1 files changed, 23 insertions(+) diff -puN include/linux/list.h~list-introduce-list_replace-helper include/linux/list.h --- devel/include/linux/list.h~list-introduce-list_replace-helper 2006-05-18 01:25:32.000000000 -0700 +++ devel-akpm/include/linux/list.h 2006-05-18 01:25:32.000000000 -0700 @@ -190,12 +190,35 @@ static inline void list_del_rcu(struct l entry->prev = LIST_POISON2; } +/** + * list_replace - replace old entry by new one + * @old : the element to be replaced + * @new : the new element to insert + * Note: if 'old' was empty, it will be overwritten. + */ +static inline void list_replace(struct list_head *old, + struct list_head *new) +{ + new->next = old->next; + new->next->prev = new; + new->prev = old->prev; + new->prev->next = new; +} + +static inline void list_replace_init(struct list_head *old, + struct list_head *new) +{ + list_replace(old, new); + INIT_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) _