rculfhash: document node alignment

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

diff --git a/urcu/rculfhash.h b/urcu/rculfhash.h
index b98b4932922e02fab3cd53e6630a46ca3b848a06..40fe4df6bd763f81240b4d08d8bfa7047e344ec1 100644 (file)
--- a/urcu/rculfhash.h
+++ b/urcu/rculfhash.h
@@ -8,6 +8,11 @@
 extern "C" {
 #endif
 
+/*
+ * struct rcu_ht_node and struct _rcu_ht_node should be aligned on
+ * 4-bytes boundaries because the two lower bits are used as flags.
+ */
+
 struct _rcu_ht_node {
        struct rcu_ht_node *next;       /* ptr | DUMMY_FLAG | REMOVED_FLAG */
        unsigned long reverse_hash;