ifb: add performance flags

Le lundi 03 janvier 2011 à 11:40 -0800, David Miller a écrit :
> From: Jarek Poplawski <jarkao2@gmail.com>
> Date: Mon, 3 Jan 2011 20:37:03 +0100
>
> > On Sun, Jan 02, 2011 at 09:24:36PM +0100, Eric Dumazet wrote:
> >> Le mercredi 29 décembre 2010 ?? 00:07 +0100, Jarek Poplawski a écrit :
> >>
> >> > Ingress is before vlans handler so these features and the
> >> > NETIF_F_HW_VLAN_TX flag seem useful for ifb considering
> >> > dev_hard_start_xmit() checks.
> >>
> >> OK, here is v2 of the patch then, thanks everybody.
> >>
> >>
> >> [PATCH v2 net-next-2.6] ifb: add performance flags
> >>
> >> IFB can use the full set of features flags (NETIF_F_SG |
> >> NETIF_F_FRAGLIST | NETIF_F_TSO | NETIF_F_NO_CSUM | NETIF_F_HIGHDMA) to
> >> avoid unnecessary split of some packets (GRO for example)
> >>
> >> Changli suggested to also set vlan_features,
> >
> > He also suggested more GSO flags of which especially NETIF_F_TSO6
> > seems interesting (wrt GRO)?
>
> I think at least TSO6 would very much be appropriate here.

Yes, why not, I am only wondering why loopback / dummy (and others ?)
only set NETIF_F_TSO :)

Since I want to play with ECN, I might also add NETIF_F_TSO_ECN ;)

For other flags, I really doubt it can matter on ifb ?

[PATCH v3 net-next-2.6] ifb: add performance flags

IFB can use the full set of features flags (NETIF_F_SG |
NETIF_F_FRAGLIST | NETIF_F_TSO | NETIF_F_NO_CSUM | NETIF_F_HIGHDMA) to
avoid unnecessary split of some packets (GRO for example)

Changli suggested to also set vlan_features, NETIF_F_TSO6,
NETIF_F_TSO_ECN.

Jarek suggested to add NETIF_F_HW_VLAN_TX as well.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Changli Gao <xiaosuo@gmail.com>
Cc: Jarek Poplawski <jarkao2@gmail.com>
Cc: Pawel Staszewski <pstaszewski@itcare.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ifb.c

@@ -126,6 +126,10 @@ static const struct net_device_ops ifb_netdev_ops = {
 	.ndo_validate_addr = eth_validate_addr,
 };
 
+#define IFB_FEATURES (NETIF_F_NO_CSUM | NETIF_F_SG  | NETIF_F_FRAGLIST	| \
+		      NETIF_F_TSO_ECN | NETIF_F_TSO | NETIF_F_TSO6	| \
+		      NETIF_F_HIGHDMA | NETIF_F_HW_VLAN_TX)
+
 static void ifb_setup(struct net_device *dev)
 {
 	/* Initialize the device structure. */
@@ -136,6 +140,9 @@ static void ifb_setup(struct net_device *dev)
 	ether_setup(dev);
 	dev->tx_queue_len = TX_Q_LIMIT;
 
+	dev->features |= IFB_FEATURES;
+	dev->vlan_features |= IFB_FEATURES;
+
 	dev->flags |= IFF_NOARP;
 	dev->flags &= ~IFF_MULTICAST;
 	dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;