[PATCH net-next v2 5/5] net: bridge: Refactor bridge port in locked mode to use jump labels

Hans Schultz
2022-02-09T13:06:41Z

From: Hans Schultz <schultz.hans+lkml@gmail.com>

As the locked mode feature is in the hot path of the bridge modules
reception of packets, it needs to be refactored to use jump labels
for optimization.

Signed-off-by: Hans Schultz <schultz.hans+lkml@gmail.com>
Signed-off-by: Hans Schultz <schultz.hans+netdev@gmail.com>
---
net/bridge/br_input.c | 22 ++++++++++++++++++----
net/bridge/br_netlink.c | 6 ++++++
net/bridge/br_private.h | 2 ++
3 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index 469e3adbce07..6fc428d6bac5 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -23,6 +23,18 @@
#include "br_private.h"
#include "br_private_tunnel.h"

+static struct static_key_false br_input_locked_port_feature;
+
+void br_input_locked_port_add(void)
+{
+ static_branch_inc(&br_input_locked_port_feature);
+}
+
+void br_input_locked_port_remove(void)
+{
+ static_branch_dec(&br_input_locked_port_feature);
+}
+
static int
br_netif_receive_skb(struct net *net, struct sock *sk, struct sk_buff *skb)
{
@@ -91,10 +103,12 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb
&state, &vlan))
goto out;

- if (p->flags & BR_PORT_LOCKED) {
- fdb_entry = br_fdb_find_rcu(br, eth_hdr(skb)->h_source, vid);
- if (!(fdb_entry && fdb_entry->dst == p))
- goto drop;
+ if (static_branch_unlikely(&br_input_locked_port_feature)) {
+ if (p->flags & BR_PORT_LOCKED) {
+ fdb_entry = br_fdb_find_rcu(br, eth_hdr(skb)->h_source, vid);
+ if (!(fdb_entry && fdb_entry->dst == p))
+ goto drop;
+ }
}

nbp_switchdev_frame_mark(p, skb);
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 7d4432ca9a20..e3dbe9fed75c 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -860,6 +860,7 @@ static int br_set_port_state(struct net_bridge_port *p, u8 state)
static void br_set_port_flag(struct net_bridge_port *p, struct nlattr *tb[],
int attrtype, unsigned long mask)
{
+ bool locked = p->flags & BR_PORT_LOCKED;
if (!tb[attrtype])
return;

@@ -867,6 +868,11 @@ static void br_set_port_flag(struct net_bridge_port *p, struct nlattr *tb[],
p->flags |= mask;
else
p->flags &= ~mask;
+
+ if ((p->flags & BR_PORT_LOCKED) && !locked)
+ br_input_locked_port_add();
+ if (!(p->flags & BR_PORT_LOCKED) && locked)
+ br_input_locked_port_remove();
}

/* Process bridge protocol info on port */
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 2661dda1a92b..0ec3ef897978 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -832,6 +832,8 @@ void br_manage_promisc(struct net_bridge *br);
int nbp_backup_change(struct net_bridge_port *p, struct net_device *backup_dev);

/* br_input.c */
+void br_input_locked_port_add(void);
+void br_input_locked_port_remove(void);
int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb);
rx_handler_func_t *br_get_rx_handler(const struct net_device *dev);

--
2.30.2