datapath: Reduce locking requirements.

[sliver-openvswitch.git] / datapath / flow.c

diff --git a/datapath/flow.c b/datapath/flow.c
index 5d1d2f2..f270f3a 100644 (file)
--- a/datapath/flow.c
+++ b/datapath/flow.c
@@ -123,8 +123,9 @@ unlock:
        spin_unlock(&stats->lock);
 }
 
-/* Called with ovs_mutex. */
-void ovs_flow_stats_get(struct sw_flow *flow, struct ovs_flow_stats *ovs_stats,
+/* Must be called with rcu_read_lock or ovs_mutex. */
+void ovs_flow_stats_get(const struct sw_flow *flow,
+                       struct ovs_flow_stats *ovs_stats,
                        unsigned long *used, __be16 *tcp_flags)
 {
        int node;
@@ -134,7 +135,7 @@ void ovs_flow_stats_get(struct sw_flow *flow, struct ovs_flow_stats *ovs_stats,
        memset(ovs_stats, 0, sizeof(*ovs_stats));
 
        for_each_node(node) {
-               struct flow_stats *stats = ovsl_dereference(flow->stats[node]);
+               struct flow_stats *stats = rcu_dereference_ovsl(flow->stats[node]);
 
                if (stats) {
                        /* Local CPU may write on non-local stats, so we must
@@ -151,12 +152,13 @@ void ovs_flow_stats_get(struct sw_flow *flow, struct ovs_flow_stats *ovs_stats,
        }
 }
 
+/* Called with ovs_mutex. */
 void ovs_flow_stats_clear(struct sw_flow *flow)
 {
        int node;
 
        for_each_node(node) {
-               struct flow_stats *stats = rcu_dereference(flow->stats[node]);
+               struct flow_stats *stats = ovsl_dereference(flow->stats[node]);
 
                if (stats) {
                        spin_lock_bh(&stats->lock);