X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=blobdiff_plain;f=include%2Flinux%2Frculist_nulls.h;h=1c33dd7da4a7d860004264e00bd406645df1ed96;hp=2ae13714828bc42568e77684fedfc2cf929c291d;hb=9fb13f7e3023941beb41536f399c065acdb4a1a6;hpb=8beeb76aa534e9312fdae1c91ab3a2effc847ee5

diff --git a/include/linux/rculist_nulls.h b/include/linux/rculist_nulls.h
index 2ae13714828b..1c33dd7da4a7 100644
--- a/include/linux/rculist_nulls.h
+++ b/include/linux/rculist_nulls.h
@@ -105,9 +105,14 @@ static inline void hlist_nulls_add_head_rcu(struct hlist_nulls_node *n,
  * @head:	the head for your list.
  * @member:	the name of the hlist_nulls_node within the struct.
  *
+ * The barrier() is needed to make sure compiler doesn't cache first element [1],
+ * as this loop can be restarted [2]
+ * [1] Documentation/atomic_ops.txt around line 114
+ * [2] Documentation/RCU/rculist_nulls.txt around line 146
  */
 #define hlist_nulls_for_each_entry_rcu(tpos, pos, head, member)			\
-	for (pos = rcu_dereference_raw(hlist_nulls_first_rcu(head));		\
+	for (({barrier();}),							\
+	     pos = rcu_dereference_raw(hlist_nulls_first_rcu(head));		\
 		(!is_a_nulls(pos)) &&						\
 		({ tpos = hlist_nulls_entry(pos, typeof(*tpos), member); 1; }); \
 		pos = rcu_dereference_raw(hlist_nulls_next_rcu(pos)))