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From: Jesper Dangaard Brouer <brouer@redhat•com>
To: Eric Dumazet <eric.dumazet@gmail•com>
Cc: Saeed Mahameed <saeedm@dev•mellanox.co.il>,
	Rick Jones <rick.jones2@hpe•com>,
	Linux Netdev List <netdev@vger•kernel.org>,
	Saeed Mahameed <saeedm@mellanox•com>,
	Tariq Toukan <tariqt@mellanox•com>,
	brouer@redhat•com
Subject: Re: [WIP] net+mlx4: auto doorbell
Date: Thu, 1 Dec 2016 20:17:07 +0100	[thread overview]
Message-ID: <20161201201707.5f51a02e@redhat.com> (raw)
In-Reply-To: <1480611857.18162.319.camel@edumazet-glaptop3.roam.corp.google.com>


On Thu, 01 Dec 2016 09:04:17 -0800 Eric Dumazet <eric.dumazet@gmail•com> wrote:

> BTW, if you are doing tests on mlx4 40Gbit,

I'm mostly testing with mlx5 50Gbit, but I do have 40G NIC in the
machines too.

>  would you check the
> following quick/dirty hack, using lots of low-rate flows ?

What tool should I use to send "low-rate flows"?

And what am I looking for?

> mlx4 has really hard time to transmit small TSO packets (2 or 3 MSS)
> 
> diff --git a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
> index 12ea3405f442..96940666abd3 100644
> --- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
> +++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
> @@ -2631,6 +2631,11 @@ static void mlx4_en_del_vxlan_port(struct  net_device *dev,
>         queue_work(priv->mdev->workqueue, &priv->vxlan_del_task);
>  }
>  
> +static int mlx4_gso_segs_min = 4; /* TSO packets with less than 4 segments are segmented */
> +module_param_named(mlx4_gso_segs_min, mlx4_gso_segs_min, uint, 0644);
> +MODULE_PARM_DESC(mlx4_gso_segs_min, "threshold for software segmentation of small TSO packets");
> +
> +
>  static netdev_features_t mlx4_en_features_check(struct sk_buff *skb,
>                                                 struct net_device *dev,
>                                                 netdev_features_t features)
> @@ -2651,6 +2656,8 @@ static netdev_features_t mlx4_en_features_check(struct sk_buff *skb,
>                     (udp_hdr(skb)->dest != priv->vxlan_port))
>                         features &= ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
>         }
> +       if (skb_is_gso(skb) && skb_shinfo(skb)->gso_segs < mlx4_gso_segs_min)
> +               features &= NETIF_F_GSO_MASK;
>  
>         return features;
>  }
 

-- 
Best regards,
  Jesper Dangaard Brouer
  MSc.CS, Principal Kernel Engineer at Red Hat
  LinkedIn: http://www.linkedin.com/in/brouer

  reply	other threads:[~2016-12-01 19:17 UTC|newest]

Thread overview: 62+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-09-03 14:59 High perf top ip_idents_reserve doing netperf UDP_STREAM Jesper Dangaard Brouer
2014-09-03 15:17 ` Eric Dumazet
2016-11-16 12:16   ` Netperf UDP issue with connected sockets Jesper Dangaard Brouer
2016-11-16 17:46     ` Rick Jones
2016-11-16 22:40       ` Jesper Dangaard Brouer
2016-11-16 22:50         ` Rick Jones
2016-11-17  0:34         ` Eric Dumazet
2016-11-17  8:16           ` Jesper Dangaard Brouer
2016-11-17 13:20             ` Eric Dumazet
2016-11-17 13:42               ` Jesper Dangaard Brouer
2016-11-17 14:17                 ` Eric Dumazet
2016-11-17 14:57                   ` Jesper Dangaard Brouer
2016-11-17 16:21                     ` Eric Dumazet
2016-11-17 18:30                       ` Jesper Dangaard Brouer
2016-11-17 18:51                         ` Eric Dumazet
2016-11-17 21:19                           ` Jesper Dangaard Brouer
2016-11-17 21:44                             ` Eric Dumazet
2016-11-17 23:08                               ` Rick Jones
2016-11-18  0:37                                 ` Julian Anastasov
2016-11-18  0:42                                   ` Rick Jones
2016-11-18 17:12                               ` Jesper Dangaard Brouer
2016-11-21 16:03                           ` Jesper Dangaard Brouer
2016-11-21 18:10                             ` Eric Dumazet
2016-11-29  6:58                               ` [WIP] net+mlx4: auto doorbell Eric Dumazet
2016-11-30 11:38                                 ` Jesper Dangaard Brouer
2016-11-30 15:56                                   ` Eric Dumazet
2016-11-30 19:17                                     ` Jesper Dangaard Brouer
2016-11-30 19:30                                       ` Eric Dumazet
2016-11-30 22:30                                         ` Jesper Dangaard Brouer
2016-11-30 22:40                                           ` Eric Dumazet
2016-12-01  0:27                                         ` Eric Dumazet
2016-12-01  1:16                                           ` Tom Herbert
2016-12-01  2:32                                             ` Eric Dumazet
2016-12-01  2:50                                               ` Eric Dumazet
2016-12-02 18:16                                                 ` Eric Dumazet
2016-12-01  5:03                                               ` Tom Herbert
2016-12-01 19:24                                                 ` Willem de Bruijn
2016-11-30 13:50                                 ` Saeed Mahameed
2016-11-30 15:44                                   ` Eric Dumazet
2016-11-30 16:27                                     ` Saeed Mahameed
2016-11-30 17:28                                       ` Eric Dumazet
2016-12-01 12:05                                       ` Jesper Dangaard Brouer
2016-12-01 14:24                                         ` Eric Dumazet
2016-12-01 16:04                                           ` Jesper Dangaard Brouer
2016-12-01 17:04                                             ` Eric Dumazet
2016-12-01 19:17                                               ` Jesper Dangaard Brouer [this message]
2016-12-01 20:11                                                 ` Eric Dumazet
2016-12-01 20:20                                               ` David Miller
2016-12-01 22:10                                                 ` Eric Dumazet
2016-12-02 14:23                                               ` Eric Dumazet
2016-12-01 21:32                                 ` Alexander Duyck
2016-12-01 22:04                                   ` Eric Dumazet
2016-11-17 17:34                     ` Netperf UDP issue with connected sockets David Laight
2016-11-17 22:39                       ` Alexander Duyck
2016-11-17 17:42             ` Rick Jones
2016-11-28 18:33             ` Rick Jones
2016-11-28 18:40               ` Rick Jones
2016-11-30 10:43               ` Jesper Dangaard Brouer
2016-11-30 17:42                 ` Rick Jones
2016-11-30 18:11                   ` David Miller
  -- strict thread matches above, loose matches on Subject: below --
2016-11-30  7:28 [WIP] net+mlx4: auto doorbell Alexei Starovoitov
2016-11-30 15:50 ` Eric Dumazet

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