diff options
| -rw-r--r-- | net/rds/xlist.h | 54 |
1 files changed, 12 insertions, 42 deletions
diff --git a/net/rds/xlist.h b/net/rds/xlist.h index 8c21aca49d50..e6b5190daddd 100644 --- a/net/rds/xlist.h +++ b/net/rds/xlist.h @@ -10,13 +10,18 @@ struct xlist_head { struct xlist_head *next; }; -/* - * XLIST_PTR_TAIL can be used to prevent double insertion. See - * xlist_protect() - */ -#define XLIST_PTR_TAIL ((struct xlist_head *)0x1) +static inline void INIT_XLIST_HEAD(struct xlist_head *list) +{ + list->next = NULL; +} + +static inline int xlist_empty(struct xlist_head *head) +{ + return head->next == NULL; +} -static inline void xlist_add(struct xlist_head *new, struct xlist_head *tail, struct xlist_head *head) +static inline void xlist_add(struct xlist_head *new, struct xlist_head *tail, + struct xlist_head *head) { struct xlist_head *cur; struct xlist_head *check; @@ -30,26 +35,6 @@ static inline void xlist_add(struct xlist_head *new, struct xlist_head *tail, st } } -/* - * To avoid duplicate insertion by two CPUs of the same xlist item - * you can call xlist_protect. It will stuff XLIST_PTR_TAIL - * into the entry->next pointer with xchg, and only return 1 - * if there was a NULL there before. - * - * if xlist_protect returns zero, someone else is busy working - * on this entry. Getting a NULL into the entry in a race - * free manner is the caller's job. - */ -static inline int xlist_protect(struct xlist_head *entry) -{ - struct xlist_head *val; - - val = xchg(&entry->next, XLIST_PTR_TAIL); - if (val == NULL) - return 1; - return 0; -} - static inline struct xlist_head *xlist_del_head(struct xlist_head *head) { struct xlist_head *cur; @@ -61,11 +46,6 @@ static inline struct xlist_head *xlist_del_head(struct xlist_head *head) if (!cur) goto out; - if (cur == XLIST_PTR_TAIL) { - cur = NULL; - goto out; - } - next = cur->next; check = cmpxchg(&head->next, cur, next); if (check == cur) @@ -80,7 +60,7 @@ static inline struct xlist_head *xlist_del_head_fast(struct xlist_head *head) struct xlist_head *cur; cur = head->next; - if (!cur || cur == XLIST_PTR_TAIL) + if (!cur) return NULL; head->next = cur->next; @@ -97,14 +77,4 @@ static inline void xlist_splice(struct xlist_head *list, head->next = cur; } -static inline void INIT_XLIST_HEAD(struct xlist_head *list) -{ - list->next = NULL; -} - -static inline int xlist_empty(struct xlist_head *head) -{ - return head->next == NULL || head->next == XLIST_PTR_TAIL; -} - #endif |