[PATCH net-next] bonding: refine IFF_XMIT_DST_RELEASE capability
From: Eric Dumazet <hidden>
Date: 2012-07-17 22:19:55
Subsystem:
bonding driver, networking drivers, the rest · Maintainers:
Jay Vosburgh, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Eric Dumazet <edumazet@google.com> Some workloads greatly benefit of IFF_XMIT_DST_RELEASE capability on output net device, avoiding dirtying dst refcount. bonding currently disables IFF_XMIT_DST_RELEASE unconditionally. If all slaves have the IFF_XMIT_DST_RELEASE bit set, then bonding master can also have it in its priv_flags Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Jay Vosburgh <redacted> Cc: Andy Gospodarek <andy@greyhouse.net> Cc: Tom Herbert <redacted> --- drivers/net/bonding/bond_main.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 1eb3979..3960b1b 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c@@ -1382,6 +1382,7 @@ static void bond_compute_features(struct bonding *bond) netdev_features_t vlan_features = BOND_VLAN_FEATURES; unsigned short max_hard_header_len = ETH_HLEN; int i; + unsigned int flags, dst_release_flag = IFF_XMIT_DST_RELEASE; read_lock(&bond->lock);
@@ -1392,6 +1393,7 @@ static void bond_compute_features(struct bonding *bond) vlan_features = netdev_increment_features(vlan_features, slave->dev->vlan_features, BOND_VLAN_FEATURES); + dst_release_flag &= slave->dev->priv_flags; if (slave->dev->hard_header_len > max_hard_header_len) max_hard_header_len = slave->dev->hard_header_len; }
@@ -1400,6 +1402,9 @@ done: bond_dev->vlan_features = vlan_features; bond_dev->hard_header_len = max_hard_header_len; + flags = bond_dev->priv_flags & ~IFF_XMIT_DST_RELEASE; + bond_dev->priv_flags = flags | dst_release_flag; + read_unlock(&bond->lock); netdev_change_features(bond_dev);