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-rw-r--r--include/linux/list.h30
1 files changed, 30 insertions, 0 deletions
diff --git a/include/linux/list.h b/include/linux/list.h
index 9b9b0eec1e8..e6ec5968227 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -634,6 +634,21 @@ static inline void hlist_add_after(struct hlist_node *n,
next->next->pprev = &next->next;
}
+/**
+ * hlist_add_before_rcu - adds the specified element to the specified hlist
+ * before the specified node while permitting racing traversals.
+ * @n: the new element to add to the hash list.
+ * @next: the existing element to add the new element before.
+ *
+ * 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_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)
{
@@ -644,6 +659,21 @@ static inline void hlist_add_before_rcu(struct hlist_node *n,
*(n->pprev) = n;
}
+/**
+ * hlist_add_after_rcu - adds the specified element to the specified hlist
+ * after the specified node while permitting racing traversals.
+ * @prev: the existing element to add the new element after.
+ * @n: the new element to add to 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_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)
{