On Wed, 2011-07-13 at 08:52 -0500, Andy Fleming wrote: > The QDisc code does a bunch of locking which is unnecessary if > you have hardware which handles all of the queueing. Add > support for this, and skip over all of the queueing code if > the feature is enabled on a given device, which breaks QDisc > support on dpaa_eth, and also coopts the FCOE feature bit. > > Signed-off-by: Andy Fleming <[email protected]> > Signed-off-by: Ben Collins <[email protected]> > Cc: [email protected] > --- > include/linux/netdev_features.h | 2 ++ > net/core/dev.c | 6 ++++++ > 2 files changed, 8 insertions(+) > > diff --git a/include/linux/netdev_features.h b/include/linux/netdev_features.h > index 3dd3934..ffb4587 100644 > --- a/include/linux/netdev_features.h > +++ b/include/linux/netdev_features.h > @@ -56,6 +56,7 @@ enum { > NETIF_F_LOOPBACK_BIT, /* Enable loopback */ > NETIF_F_RXFCS_BIT, /* Append FCS to skb pkt data */ > NETIF_F_RXALL_BIT, /* Receive errored frames too */ > + NETIF_F_HW_QDISC_BIT, /* Supports hardware Qdisc */ > > /* > * Add your fresh new feature above and remember to update > @@ -80,6 +81,7 @@ enum { > #define NETIF_F_GSO_ROBUST __NETIF_F(GSO_ROBUST) > #define NETIF_F_HIGHDMA __NETIF_F(HIGHDMA) > #define NETIF_F_HW_CSUM __NETIF_F(HW_CSUM) > +#define NETIF_F_HW_QDISC __NETIF_F(HW_QDISC) > #define NETIF_F_HW_VLAN_FILTER __NETIF_F(HW_VLAN_FILTER) > #define NETIF_F_HW_VLAN_RX __NETIF_F(HW_VLAN_RX) > #define NETIF_F_HW_VLAN_TX __NETIF_F(HW_VLAN_TX) > diff --git a/net/core/dev.c b/net/core/dev.c > index dffbef7..6818b18 100644 > --- a/net/core/dev.c > +++ b/net/core/dev.c > @@ -2743,6 +2743,12 @@ int dev_queue_xmit(struct sk_buff *skb) > > skb_update_prio(skb); > > + if (dev->features & NETIF_F_HW_QDISC) { > + txq = netdev_pick_tx(dev, skb); > + rc = dev_hard_start_xmit(skb, dev, txq); > + goto out; > + } > + > txq = netdev_pick_tx(dev, skb); > q = rcu_dereference_bh(txq->qdisc); >
Nobody forces you to use a qdisc. And if your device really is lockless, it can use NETIF_F_LLTX feature. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
