X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=include%2Flinux%2Flist.h;h=33b863bcb7b9a017a7d1e8f2e870dc6318f31662;hb=9bf4aaab3e101692164d49b7ca357651eb691cb6;hp=9e0c971ded6f7284328c747d03e45e401ac59944;hpb=db216c3d5e4c040e557a50f8f5d35d5c415e8c1c;p=linux-2.6.git

diff --git a/include/linux/list.h b/include/linux/list.h
index 9e0c971de..33b863bcb 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -620,13 +620,12 @@ static inline void hlist_add_after(struct hlist_node *n,
 
 #define hlist_entry(ptr, type, member) container_of(ptr,type,member)
 
-/* Cannot easily do prefetch unfortunately */
 #define hlist_for_each(pos, head) \
 	for (pos = (head)->first; pos && ({ prefetch(pos->next); 1; }); \
 	     pos = pos->next)
 
 #define hlist_for_each_safe(pos, n, head) \
-	for (pos = (head)->first; n = pos ? pos->next : 0, pos; \
+	for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \
 	     pos = n)
 
 /**
@@ -678,6 +677,24 @@ static inline void hlist_add_after(struct hlist_node *n,
 	     pos && ({ n = pos->next; 1; }) && 				 \
 		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
 	     pos = n)
+
+/**
+ * hlist_for_each_entry_rcu - iterate over rcu list of given type
+ * @pos:	the type * to use as a loop counter.
+ * @pos:	the &struct hlist_node to use as a loop counter.
+ * @head:	the head for your list.
+ * @member:	the name of the hlist_node within the struct.
+ *
+ * This list-traversal primitive may safely run concurrently with
+ * the _rcu list-mutation primitives such as hlist_add_rcu()
+ * 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;					 \
+	     pos && ({ prefetch(pos->next); 1;}) &&			 \
+		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
+	     pos = pos->next, ({ smp_read_barrier_depends(); 0; }) )
+
 #else
 #warning "don't include kernel headers in userspace"
 #endif /* __KERNEL__ */