From: Amir Vadai <amirv@mellanox•com>
To: Eric Dumazet <eric.dumazet@gmail•com>,
"David S. Miller" <davem@davemloft•net>
Cc: Eric Dumazet <edumazet@google•com>, <netdev@vger•kernel.org>,
"Yevgeny Petrilin" <yevgenyp@mellanox•com>,
Or Gerlitz <ogerlitz@mellanox•com>,
"Ido Shamay" <idos@mellanox•com>
Subject: Re: [PATCH net-next] net: introduce netdevice gso_min_segs attribute
Date: Mon, 6 Oct 2014 09:41:31 +0300 [thread overview]
Message-ID: <5432399B.3060406@mellanox.com> (raw)
In-Reply-To: <1412529087.11091.14.camel@edumazet-glaptop2.roam.corp.google.com>
On 10/5/2014 8:11 PM, Eric Dumazet wrote:
> From: Eric Dumazet <edumazet@google•com>
>
> Some TSO engines might have a too heavy setup cost, that impacts
> performance on hosts sending small bursts (2 MSS per packet).
>
> This patch adds a device gso_min_segs, allowing drivers to set
> a minimum segment size for TSO packets, according to the NIC
> performance.
>
> Tested on a mlx4 NIC, this allows to get a ~110% increase of
> throughput when sending 2 MSS per packet.
>
Amazing!
Shouldn't there be a netif_set_gso_min_size() too?
> Signed-off-by: Eric Dumazet <edumazet@google•com>
> ---
> mlx4 patch will be sent later, its a one liner.
>
> include/linux/netdevice.h | 4 +++-
> net/core/dev.c | 9 ++++++---
> 2 files changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> index 22d54b9b700d..2df86f50261c 100644
> --- a/include/linux/netdevice.h
> +++ b/include/linux/netdevice.h
> @@ -1416,6 +1416,8 @@ enum netdev_priv_flags {
> * @gso_max_size: Maximum size of generic segmentation offload
> * @gso_max_segs: Maximum number of segments that can be passed to the
> * NIC for GSO
> + * @gso_min_segs: Minimum number of segments that can be passed to the
> + * NIC for GSO
> *
> * @dcbnl_ops: Data Center Bridging netlink ops
> * @num_tc: Number of traffic classes in the net device
> @@ -1666,7 +1668,7 @@ struct net_device {
> unsigned int gso_max_size;
> #define GSO_MAX_SEGS 65535
> u16 gso_max_segs;
> -
> + u16 gso_min_segs;
> #ifdef CONFIG_DCB
> const struct dcbnl_rtnl_ops *dcbnl_ops;
> #endif
> diff --git a/net/core/dev.c b/net/core/dev.c
> index 1a90530f83ff..16e8ebbd3316 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -2567,10 +2567,12 @@ static netdev_features_t harmonize_features(struct sk_buff *skb,
>
> netdev_features_t netif_skb_features(struct sk_buff *skb)
> {
> + const struct net_device *dev = skb->dev;
> + netdev_features_t features = dev->features;
> + u16 gso_segs = skb_shinfo(skb)->gso_segs;
> __be16 protocol = skb->protocol;
> - netdev_features_t features = skb->dev->features;
>
> - if (skb_shinfo(skb)->gso_segs > skb->dev->gso_max_segs)
> + if (gso_segs > dev->gso_max_segs || gso_segs < dev->gso_min_segs)
> features &= ~NETIF_F_GSO_MASK;
>
> if (protocol == htons(ETH_P_8021Q) || protocol == htons(ETH_P_8021AD)) {
> @@ -2581,7 +2583,7 @@ netdev_features_t netif_skb_features(struct sk_buff *skb)
> }
>
> features = netdev_intersect_features(features,
> - skb->dev->vlan_features |
> + dev->vlan_features |
> NETIF_F_HW_VLAN_CTAG_TX |
> NETIF_F_HW_VLAN_STAG_TX);
>
> @@ -6658,6 +6660,7 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
>
> dev->gso_max_size = GSO_MAX_SIZE;
> dev->gso_max_segs = GSO_MAX_SEGS;
> + dev->gso_min_segs = 0;
>
> INIT_LIST_HEAD(&dev->napi_list);
> INIT_LIST_HEAD(&dev->unreg_list);
>
>
next prev parent reply other threads:[~2014-10-06 6:41 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-05 9:35 [PATCH net-next 00/14] net/mlx4_en: Optimizations to TX flow Amir Vadai
2014-10-05 9:35 ` [PATCH net-next 01/14] net/mlx4_en: Code cleanups in tx path Amir Vadai
2014-10-05 9:35 ` [PATCH net-next 02/14] net/mlx4_en: Align tx path structures to cache lines Amir Vadai
2014-10-05 9:35 ` [PATCH net-next 03/14] net/mlx4_en: Avoid calling bswap in tx fast path Amir Vadai
2014-10-05 9:35 ` [PATCH net-next 04/14] net/mlx4_en: tx_info allocated with kmalloc() instead of vmalloc() Amir Vadai
2014-10-05 9:35 ` [PATCH net-next 05/14] net/mlx4_en: Avoid a cache line miss in TX completion for single frag skb's Amir Vadai
2014-10-05 9:35 ` [PATCH net-next 06/14] net/mlx4_en: Use prefetch in tx path Amir Vadai
2014-10-05 9:35 ` [PATCH net-next 07/14] net/mlx4_en: Avoid false sharing in mlx4_en_en_process_tx_cq() Amir Vadai
2014-10-05 9:35 ` [PATCH net-next 08/14] net/mlx4_en: mlx4_en_xmit() reads ring->cons once, and ahead of time to avoid stalls Amir Vadai
2014-10-05 9:35 ` [PATCH net-next 09/14] net/mlx4_en: Use local var in tx flow for skb_shinfo(skb) Amir Vadai
2014-10-05 9:35 ` [PATCH net-next 10/14] net/mlx4_en: Use local var for skb_headlen(skb) Amir Vadai
2014-10-05 9:35 ` [PATCH net-next 11/14] net/mlx4_en: tx_info->ts_requested was not cleared Amir Vadai
2014-10-05 9:35 ` [PATCH net-next 12/14] net/mlx4_en: Enable the compiler to make is_inline() inlined Amir Vadai
2014-10-05 9:35 ` [PATCH net-next 13/14] ethtool: Ethtool parameter to dynamically change tx_copybreak Amir Vadai
2014-10-05 9:35 ` [PATCH net-next 14/14] net/mlx4_en: Use the new tx_copybreak to set inline threshold Amir Vadai
2014-10-05 13:03 ` Sergei Shtylyov
2014-10-05 11:45 ` [PATCH net-next 00/14] net/mlx4_en: Optimizations to TX flow Amir Vadai
2014-10-05 15:50 ` Eric Dumazet
2014-10-05 17:11 ` [PATCH net-next] net: introduce netdevice gso_min_segs attribute Eric Dumazet
2014-10-05 18:45 ` Tom Herbert
2014-10-05 18:58 ` Eric Dumazet
2014-10-06 6:41 ` Amir Vadai [this message]
2014-10-06 12:17 ` Eric Dumazet
2014-10-06 12:22 ` Eric Dumazet
2014-10-06 10:20 ` David Laight
2014-10-06 12:14 ` Eric Dumazet
2014-10-06 21:21 ` David Miller
2014-10-06 21:42 ` Eric Dumazet
2014-10-06 21:54 ` David Miller
2014-10-06 22:26 ` Eric Dumazet
2014-10-06 5:04 ` [PATCH net-next 00/14] net/mlx4_en: Optimizations to TX flow David Miller
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