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

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Date:   Thu, 10 Feb 2022 10:22:17 +0100
From:   Hans Schultz <schultz.hans@...il.com>
To:     Nikolay Aleksandrov <razor@...ckwall.org>,
        Hans Schultz <schultz.hans@...il.com>, davem@...emloft.net,
        kuba@...nel.org
Cc:     netdev@...r.kernel.org, Hans Schultz <schultz.hans+lkml@...il.com>,
        Roopa Prabhu <roopa@...dia.com>,
        Nikolay Aleksandrov <nikolay@...dia.com>,
        bridge@...ts.linux-foundation.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH net-next v2 5/5] net: bridge: Refactor bridge port in
 locked mode to use jump labels

On tor, feb 10, 2022 at 10:31, Nikolay Aleksandrov <razor@...ckwall.org> wrote:
> On 09/02/2022 15:05, Hans Schultz wrote:
>> From: Hans Schultz <schultz.hans+lkml@...il.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@...il.com>
>> Signed-off-by: Hans Schultz <schultz.hans+netdev@...il.com>
>> ---
>
> Why two (almost) identical sign-offs?

Ups, a mistake...

>
> Also, as Ido mentioned, please fold this patch into patch 01.
>
>>  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);
>>