From: Eric Dumazet <eric.dumazet@gmail.com>
To: Andy Fleming <afleming@freescale.com>
Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: [PATCH] net: Add support for handling queueing in hardware
Date: Fri, 22 Mar 2013 07:23:13 -0700 [thread overview]
Message-ID: <1363962193.4431.59.camel@edumazet-glaptop> (raw)
In-Reply-To: <E1UJ1fR-0004hs-4l@swissweb.swissdisk.com>
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 <afleming@freescale.com>
> Signed-off-by: Ben Collins <ben.c@servergy.com>
> Cc: netdev@vger.kernel.org
> ---
> 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.
next prev parent reply other threads:[~2013-03-22 14:23 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-13 13:52 [PATCH] net: Add support for handling queueing in hardware Andy Fleming
2013-03-22 14:11 ` David Miller
2013-03-22 14:31 ` Fleming Andy-AFLEMING
2013-03-22 14:33 ` David Miller
2013-03-22 14:43 ` Ben Collins
2013-03-22 15:17 ` David Miller
2013-03-22 15:39 ` Ben Collins
2013-03-22 15:41 ` David Miller
2013-03-22 15:53 ` Ben Collins
2013-03-22 15:59 ` David Miller
2013-03-22 16:14 ` Ben Collins
2013-03-22 16:16 ` David Miller
2013-03-22 16:23 ` Ben Collins
2013-03-22 22:08 ` Theodore Ts'o
2013-03-23 19:10 ` Guenter Roeck
2013-04-01 14:13 ` Mark Brown
2013-03-23 19:02 ` Guenter Roeck
2013-03-24 19:06 ` Guenter Roeck
2013-03-22 14:23 ` Eric Dumazet [this message]
2013-03-22 14:50 ` Ben Collins
2013-03-22 15:01 ` Eric Dumazet
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