bridge: avoid unnecessary read of jiffies

Jiffies is volatile so read it once.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bridge/br_fdb.c

@@ -592,13 +592,15 @@ void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 				br_warn(br, "received packet on %s with own address as source address (addr:%pM, vlan:%u)\n",
 					source->dev->name, addr, vid);
 		} else {
+			unsigned long now = jiffies;
+
 			/* fastpath: update of existing entry */
 			if (unlikely(source != fdb->dst)) {
 				fdb->dst = source;
 				fdb_modified = true;
 			}
-			if (jiffies != fdb->updated)
-				fdb->updated = jiffies;
+			if (now != fdb->updated)
+				fdb->updated = now;
 			if (unlikely(added_by_user))
 				fdb->added_by_user = 1;
 			if (unlikely(fdb_modified))

net/bridge/br_input.c

@@ -195,11 +195,13 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb
 	}
 
 	if (dst) {
+		unsigned long now = jiffies;
+
 		if (dst->is_local)
 			return br_pass_frame_up(skb);
 
-		if (jiffies != dst->used)
-			dst->used = jiffies;
+		if (now != dst->used)
+			dst->used = now;
 		br_forward(dst->dst, skb, local_rcv, false);
 	} else {
 		if (!mcast_hit)