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author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2008-05-12 21:21:06 +0200 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-05-19 10:03:39 +0200 |
commit | 78b0e0e9b27b62c4b22f05a147f7a80fa58b1ae3 (patch) | |
tree | 84c7a3e28ffc1ed92530fec7837087ad918cc8db /include/linux/rculist.h | |
parent | d7c0651390b6a03ad53f99faec0ba88109d7191d (diff) | |
download | linux-stable-78b0e0e9b27b62c4b22f05a147f7a80fa58b1ae3.tar.gz linux-stable-78b0e0e9b27b62c4b22f05a147f7a80fa58b1ae3.tar.bz2 linux-stable-78b0e0e9b27b62c4b22f05a147f7a80fa58b1ae3.zip |
RCU, rculist.h: fix list iterators
RCU list iterators: should prefetch ever be optimised out with no
side-effects, the current version will lose the barrier completely.
Pointed-out-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux/rculist.h')
-rw-r--r-- | include/linux/rculist.h | 48 |
1 files changed, 15 insertions, 33 deletions
diff --git a/include/linux/rculist.h b/include/linux/rculist.h index 8d2c81fccfe5..b0f39be08b6c 100644 --- a/include/linux/rculist.h +++ b/include/linux/rculist.h @@ -180,31 +180,14 @@ static inline void list_splice_init_rcu(struct list_head *list, * as long as the traversal is guarded by rcu_read_lock(). */ #define list_for_each_rcu(pos, head) \ - for (pos = (head)->next; \ - prefetch(rcu_dereference(pos)->next), pos != (head); \ - pos = pos->next) + 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 = (head)->next; \ - rcu_dereference(pos) != (head); \ - pos = pos->next) - -/** - * list_for_each_safe_rcu - * @pos: the &struct list_head to use as a loop cursor. - * @n: another &struct list_head to use as temporary storage - * @head: the head for your list. - * - * Iterate over an rcu-protected list, safe against removal of list entry. - * - * 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_safe_rcu(pos, n, head) \ - for (pos = (head)->next; \ - n = rcu_dereference(pos)->next, pos != (head); \ - pos = n) + 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 @@ -217,10 +200,9 @@ static inline void list_splice_init_rcu(struct list_head *list, * as long as the traversal is guarded by rcu_read_lock(). */ #define list_for_each_entry_rcu(pos, head, member) \ - for (pos = list_entry((head)->next, typeof(*pos), member); \ - prefetch(rcu_dereference(pos)->member.next), \ - &pos->member != (head); \ - pos = list_entry(pos->member.next, typeof(*pos), 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)) /** @@ -235,9 +217,9 @@ static inline void list_splice_init_rcu(struct list_head *list, * as long as the traversal is guarded by rcu_read_lock(). */ #define list_for_each_continue_rcu(pos, head) \ - for ((pos) = (pos)->next; \ - prefetch(rcu_dereference((pos))->next), (pos) != (head); \ - (pos) = (pos)->next) + for ((pos) = rcu_dereference((pos)->next); \ + prefetch((pos)->next), (pos) != (head); \ + (pos) = rcu_dereference((pos)->next)) /** * hlist_del_rcu - deletes entry from hash list without re-initialization @@ -382,10 +364,10 @@ static inline void hlist_add_after_rcu(struct hlist_node *prev, * as long as the traversal is guarded by rcu_read_lock(). */ #define hlist_for_each_entry_rcu(tpos, pos, head, member) \ - for (pos = (head)->first; \ - rcu_dereference(pos) && ({ prefetch(pos->next); 1; }) && \ + for (pos = rcu_dereference((head)->first); \ + pos && ({ prefetch(pos->next); 1; }) && \ ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1; }); \ - pos = pos->next) + pos = rcu_dereference(pos->next)) #endif /* __KERNEL__ */ #endif |