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From: Andrew Vagin <avagin@parallels•com>
To: Eric Dumazet <eric.dumazet@gmail•com>
Cc: netdev@vger•kernel.org, vvs@parallels•com,
	"Michał Mirosław" <mirq-linux@rere•qmqm.pl>
Subject: Re: Slow speed of tcp connections in a network namespace
Date: Sat, 29 Dec 2012 18:50:31 +0400	[thread overview]
Message-ID: <20121229145030.GA7959@paralelels.com> (raw)
In-Reply-To: <1356789203.21409.3923.camel@edumazet-glaptop>

On Sat, Dec 29, 2012 at 05:53:23AM -0800, Eric Dumazet wrote:
> > 3.8-rc1 is used for experiments.
> > 
> > Do you have any ideas where is a problem?
> 
> veth has absolutely no offload features
> 
> It needs some care...
> 
> At the very miminum, let TCP coalesce do its job by allowing SG
> 
> CC Michał Mirosław <mirq-linux@rere•qmqm.pl> for insights.
> 
> Please try following patch :

Hello Eric,

Thanks for your feedback.

With this patch the results is a bit better (~4MB/s), but it's much less
than in the root netns.

> 
> diff --git a/drivers/net/veth.c b/drivers/net/veth.c
> index 95814d9..9fefeb3 100644
> --- a/drivers/net/veth.c
> +++ b/drivers/net/veth.c
> @@ -259,6 +259,10 @@ static const struct net_device_ops veth_netdev_ops = {
>  	.ndo_set_mac_address = eth_mac_addr,
>  };
>  
> +#define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_TSO |	\
> +		       NETIF_F_HW_CSUM | NETIF_F_HIGHDMA |		\
> +		       NETIF_F_HW_VLAN_TX | NETIF_F_HW_VLAN_RX)
> +
>  static void veth_setup(struct net_device *dev)
>  {
>  	ether_setup(dev);
> @@ -269,9 +273,10 @@ static void veth_setup(struct net_device *dev)
>  	dev->netdev_ops = &veth_netdev_ops;
>  	dev->ethtool_ops = &veth_ethtool_ops;
>  	dev->features |= NETIF_F_LLTX;
> +	dev->features |= VETH_FEATURES;
>  	dev->destructor = veth_dev_free;
>  
> -	dev->hw_features = NETIF_F_HW_CSUM | NETIF_F_SG | NETIF_F_RXCSUM;
> +	dev->hw_features = VETH_FEATURES;
>  }
>  
>  /*
> 
> 

  reply	other threads:[~2012-12-29 14:51 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-12-29  9:24 Slow speed of tcp connections in a network namespace Andrew Vagin
2012-12-29 13:53 ` Eric Dumazet
2012-12-29 14:50   ` Andrew Vagin [this message]
2012-12-29 17:40     ` Eric Dumazet
2012-12-29 18:29       ` Andrew Vagin
2012-12-29 18:58       ` Eric Dumazet
2012-12-29 19:41         ` Eric Dumazet
2012-12-29 20:08           ` Andrew Vagin
2012-12-29 20:20             ` Eric Dumazet
2012-12-29 21:07               ` Andrew Vagin
2012-12-29 21:12             ` Eric Dumazet
2012-12-29 21:19               ` Andrew Vagin
2012-12-29 21:15         ` Andrew Vagin
2012-12-29 16:01   ` Michał Mirosław
2012-12-30  2:26     ` [PATCH] veth: extend device features Eric Dumazet
2012-12-30 10:32       ` David Miller

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