bridge: fdb: write to used and updated at most once per jiffy

Writing once per jiffy is enough to limit the bridge's false sharing.
After this change the bridge doesn't show up in the local load HitM stats.

Suggested-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index 5cbed5c0db88a95d39fa6d558c865f031cd9d78a..5028691fa68a65a7abb959605c8dd988297c0660 100644 (file)
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -597,7 +597,8 @@ void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
                                fdb->dst = source;
                                fdb_modified = true;
                        }
-                       fdb->updated = jiffies;
+                       if (jiffies != fdb->updated)
+                               fdb->updated = jiffies;
                        if (unlikely(added_by_user))
                                fdb->added_by_user = 1;
                        if (unlikely(fdb_modified))

diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index fba38d8a1a084455f9da82e6f5022294b99ed105..220943f920d272113d2d22392197078ac5b75527 100644 (file)
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -198,7 +198,8 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb
                if (dst->is_local)
                        return br_pass_frame_up(skb);
 
-               dst->used = jiffies;
+               if (jiffies != dst->used)
+                       dst->used = jiffies;
                br_forward(dst->dst, skb, local_rcv, false);
        } else {
                if (!mcast_hit)