[net-next,2/2] bnxt: Use generic HBH removal helper in tx path

Message ID 20221122232740.3180560-2-lixiaoyan@google.com
State New
Headers
Series [net-next,1/2] IPv6/GRO: generic helper to remove temporary HBH/jumbo header in driver |

Commit Message

Coco Li Nov. 22, 2022, 11:27 p.m. UTC
  Eric Dumazet implemented Big TCP that allowed bigger TSO/GRO packet sizes
for IPv6 traffic. See patch series:
'commit 89527be8d8d6 ("net: add IFLA_TSO_{MAX_SIZE|SEGS} attributes")'

This reduces the number of packets traversing the networking stack and
should usually improves performance. However, it also inserts a
temporary Hop-by-hop IPv6 extension header.

Using the HBH header removal method in the previous path, the extra header
be removed in bnxt drivers to allow it to send big TCP packets (bigger
TSO packets) as well.

If bnxt folks could help with testing this patch on the driver (as I
don't have access to one) that would be wonderful. Thank you!

Tested:
Compiled locally

To further test functional correctness, update the GSO/GRO limit on the
physical NIC:

ip link set eth0 gso_max_size 181000
ip link set eth0 gro_max_size 181000

Note that if there are bonding or ipvan devices on top of the physical
NIC, their GSO sizes need to be updated as well.

Then, IPv6/TCP packets with sizes larger than 64k can be observed.

Signed-off-by: Coco Li <lixiaoyan@google.com>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt.c | 4 ++++
 1 file changed, 4 insertions(+)
  

Comments

Alexander Lobakin Nov. 23, 2022, 4:41 p.m. UTC | #1
From: Coco Li <lixiaoyan@google.com>
Date: Tue, 22 Nov 2022 15:27:40 -0800

> Eric Dumazet implemented Big TCP that allowed bigger TSO/GRO packet sizes
> for IPv6 traffic. See patch series:
> 'commit 89527be8d8d6 ("net: add IFLA_TSO_{MAX_SIZE|SEGS} attributes")'
> 
> This reduces the number of packets traversing the networking stack and
> should usually improves performance. However, it also inserts a
> temporary Hop-by-hop IPv6 extension header.
> 
> Using the HBH header removal method in the previous path, the extra header
> be removed in bnxt drivers to allow it to send big TCP packets (bigger
> TSO packets) as well.
> 
> If bnxt folks could help with testing this patch on the driver (as I
> don't have access to one) that would be wonderful. Thank you!
> 
> Tested:
> Compiled locally

Please mark "potential" patches with 'RFC'. Then, if/when you get a
'Tested-by:', you can spin a "true" v1.

> 
> To further test functional correctness, update the GSO/GRO limit on the
> physical NIC:
> 
> ip link set eth0 gso_max_size 181000
> ip link set eth0 gro_max_size 181000
> 
> Note that if there are bonding or ipvan devices on top of the physical
> NIC, their GSO sizes need to be updated as well.
> 
> Then, IPv6/TCP packets with sizes larger than 64k can be observed.
> 
> Signed-off-by: Coco Li <lixiaoyan@google.com>
> ---
>  drivers/net/ethernet/broadcom/bnxt/bnxt.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
> index 0fe164b42c5d..2bfa5e9fb179 100644
> --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
> +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
> @@ -389,6 +389,9 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev)
>  			return NETDEV_TX_BUSY;
>  	}
>  
> +	if (unlikely(ipv6_hopopt_jumbo_remove(skb)))
> +		goto tx_free;
> +
>  	length = skb->len;
>  	len = skb_headlen(skb);
>  	last_frag = skb_shinfo(skb)->nr_frags;
> @@ -13657,6 +13660,7 @@ static int bnxt_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
>  		dev->features &= ~NETIF_F_LRO;
>  	dev->priv_flags |= IFF_UNICAST_FLT;
>  
> +	netif_set_tso_max_size(dev, GSO_MAX_SIZE);
>  #ifdef CONFIG_BNXT_SRIOV
>  	init_waitqueue_head(&bp->sriov_cfg_wait);
>  #endif
> -- 
> 2.38.1.584.g0f3c55d4c2-goog

Thanks,
Olek
  
Leon Romanovsky Nov. 28, 2022, 9:54 a.m. UTC | #2
On Wed, Nov 23, 2022 at 05:41:59PM +0100, Alexander Lobakin wrote:
> From: Coco Li <lixiaoyan@google.com>
> Date: Tue, 22 Nov 2022 15:27:40 -0800
> 
> > Eric Dumazet implemented Big TCP that allowed bigger TSO/GRO packet sizes
> > for IPv6 traffic. See patch series:
> > 'commit 89527be8d8d6 ("net: add IFLA_TSO_{MAX_SIZE|SEGS} attributes")'
> > 
> > This reduces the number of packets traversing the networking stack and
> > should usually improves performance. However, it also inserts a
> > temporary Hop-by-hop IPv6 extension header.
> > 
> > Using the HBH header removal method in the previous path, the extra header
> > be removed in bnxt drivers to allow it to send big TCP packets (bigger
> > TSO packets) as well.
> > 
> > If bnxt folks could help with testing this patch on the driver (as I
> > don't have access to one) that would be wonderful. Thank you!
> > 
> > Tested:
> > Compiled locally
> 
> Please mark "potential" patches with 'RFC'. Then, if/when you get a
> 'Tested-by:', you can spin a "true" v1.

We are getting ton of patches which are "compiled-only".
I won't be such strict with them as long as they stated clearly about it.

Thanks
  

Patch

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 0fe164b42c5d..2bfa5e9fb179 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -389,6 +389,9 @@  static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev)
 			return NETDEV_TX_BUSY;
 	}
 
+	if (unlikely(ipv6_hopopt_jumbo_remove(skb)))
+		goto tx_free;
+
 	length = skb->len;
 	len = skb_headlen(skb);
 	last_frag = skb_shinfo(skb)->nr_frags;
@@ -13657,6 +13660,7 @@  static int bnxt_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 		dev->features &= ~NETIF_F_LRO;
 	dev->priv_flags |= IFF_UNICAST_FLT;
 
+	netif_set_tso_max_size(dev, GSO_MAX_SIZE);
 #ifdef CONFIG_BNXT_SRIOV
 	init_waitqueue_head(&bp->sriov_cfg_wait);
 #endif