team: refine IFF_XMIT_DST_RELEASE capability

Cloned patch of Eric Dumazet for bonding.

Some workloads greatly benefit of IFF_XMIT_DST_RELEASE capability
on output net device, avoiding dirtying dst refcount.

team currently disables IFF_XMIT_DST_RELEASE unconditionally.

If all ports have the IFF_XMIT_DST_RELEASE bit set, then
team dev can also have it in its priv_flags.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c
index 1a13470dee07fddebf957fc6fec609e175810e11..813e1319095fb339800c5cd41b7f5e653cccbd13 100644 (file)
--- a/drivers/net/team/team.c
+++ b/drivers/net/team/team.c
@@ -733,12 +733,14 @@ static void __team_compute_features(struct team *team)
        struct team_port *port;
        u32 vlan_features = TEAM_VLAN_FEATURES;
        unsigned short max_hard_header_len = ETH_HLEN;
+       unsigned int flags, dst_release_flag = IFF_XMIT_DST_RELEASE;
 
        list_for_each_entry(port, &team->port_list, list) {
                vlan_features = netdev_increment_features(vlan_features,
                                        port->dev->vlan_features,
                                        TEAM_VLAN_FEATURES);
 
+               dst_release_flag &= port->dev->priv_flags;
                if (port->dev->hard_header_len > max_hard_header_len)
                        max_hard_header_len = port->dev->hard_header_len;
        }
@@ -746,6 +748,9 @@ static void __team_compute_features(struct team *team)
        team->dev->vlan_features = vlan_features;
        team->dev->hard_header_len = max_hard_header_len;
 
+       flags = team->dev->priv_flags & ~IFF_XMIT_DST_RELEASE;
+       team->dev->priv_flags = flags | dst_release_flag;
+
        netdev_change_features(team->dev);
 }