bridge: modify bridge and port to have often accessed fields in one cache line

Move around net_bridge so the vlan fields are in the beginning since
they're checked on every packet even if vlan filtering is disabled.
For the port move flags & vlan group to the beginning, so they're in the
same cache line with the port's state (both flags and state are checked
on each packet).

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

diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 40177df45ba6dc01d8facf7f54d4843a3fd4790e..ec8560349b6f6ec696ce689eace54e4333fab228 100644 (file)
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -212,12 +212,16 @@ struct net_bridge_mdb_htable
        u32                             ver;
 };
 
-struct net_bridge_port
-{
+struct net_bridge_port {
        struct net_bridge               *br;
        struct net_device               *dev;
        struct list_head                list;
 
+       unsigned long                   flags;
+#ifdef CONFIG_BRIDGE_VLAN_FILTERING
+       struct net_bridge_vlan_group    __rcu *vlgrp;
+#endif
+
        /* STP */
        u8                              priority;
        u8                              state;
@@ -238,8 +242,6 @@ struct net_bridge_port
        struct kobject                  kobj;
        struct rcu_head                 rcu;
 
-       unsigned long                   flags;
-
 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
        struct bridge_mcast_own_query   ip4_own_query;
 #if IS_ENABLED(CONFIG_IPV6)
@@ -259,9 +261,6 @@ struct net_bridge_port
 #ifdef CONFIG_NET_POLL_CONTROLLER
        struct netpoll                  *np;
 #endif
-#ifdef CONFIG_BRIDGE_VLAN_FILTERING
-       struct net_bridge_vlan_group    __rcu *vlgrp;
-#endif
 #ifdef CONFIG_NET_SWITCHDEV
        int                             offload_fwd_mark;
 #endif
@@ -283,14 +282,21 @@ static inline struct net_bridge_port *br_port_get_rtnl(const struct net_device *
                rtnl_dereference(dev->rx_handler_data) : NULL;
 }
 
-struct net_bridge
-{
+struct net_bridge {
        spinlock_t                      lock;
+       spinlock_t                      hash_lock;
        struct list_head                port_list;
        struct net_device               *dev;
-
        struct pcpu_sw_netstats         __percpu *stats;
-       spinlock_t                      hash_lock;
+       /* These fields are accessed on each packet */
+#ifdef CONFIG_BRIDGE_VLAN_FILTERING
+       u8                              vlan_enabled;
+       u8                              vlan_stats_enabled;
+       __be16                          vlan_proto;
+       u16                             default_pvid;
+       struct net_bridge_vlan_group    __rcu *vlgrp;
+#endif
+
        struct hlist_head               hash[BR_HASH_SIZE];
 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
        union {
@@ -308,6 +314,9 @@ struct net_bridge
        bridge_id                       designated_root;
        bridge_id                       bridge_id;
        u32                             root_path_cost;
+       unsigned char                   topology_change;
+       unsigned char                   topology_change_detected;
+       u16                             root_port;
        unsigned long                   max_age;
        unsigned long                   hello_time;
        unsigned long                   forward_delay;
@@ -319,7 +328,6 @@ struct net_bridge
 
        u8                              group_addr[ETH_ALEN];
        bool                            group_addr_set;
-       u16                             root_port;
 
        enum {
                BR_NO_STP,              /* no spanning tree */
@@ -327,9 +335,6 @@ struct net_bridge
                BR_USER_STP,            /* new RSTP in userspace */
        } stp_enabled;
 
-       unsigned char                   topology_change;
-       unsigned char                   topology_change_detected;
-
 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
        unsigned char                   multicast_router;
 
@@ -381,14 +386,6 @@ struct net_bridge
 #ifdef CONFIG_NET_SWITCHDEV
        int offload_fwd_mark;
 #endif
-
-#ifdef CONFIG_BRIDGE_VLAN_FILTERING
-       struct net_bridge_vlan_group    __rcu *vlgrp;
-       u8                              vlan_enabled;
-       u8                              vlan_stats_enabled;
-       __be16                          vlan_proto;
-       u16                             default_pvid;
-#endif
 };
 
 struct br_input_skb_cb {