Re: [PATCH net-next v2] openvswitch: raise internal port TSO limit

[Eelco Chaudron <echaudro@redhat.com>]

On 16 Sep 2026, at 8:58, Wang Zhan wrote:

> Set the internal port TSO limit to GSO_MAX_SIZE (512 KB), as for
> loopback and veth. This allows the admin/user to set a GSO limit up to
> this value, to use BIG TCP for traffic routed through the internal port.
>
> Only the capability limit changes: the IPv4 and IPv6 GSO and GRO limits
> remain at 64 KiB until changed by the administrator.
>
> Validation used a same-host test with a temporary OVS bridge, a veth pair,
> and a network namespace:
>
>   TCP client -> OVS internal -> OVS bridge -> veth -> TCP server
>
> The veth endpoints were BIG TCP capable throughout the test, and only the
> OVS internal port limits changed between 64 KiB and 524280 bytes. A single
> iperf3 3.19 TCP flow, run separately over IPv4 and IPv6 with six
> alternating runs per state (`-t 15 -O 5`, fixed CPU affinity and port
> tuple), increased throughput by 18.1% for IPv4 and 34.7% for IPv6:
>
>   protocol  BIG TCP off  BIG TCP on   CV off / on
>   TCP/IPv4  65.567 Gbps  77.420 Gbps  1.12% / 0.37%
>   TCP/IPv6  55.355 Gbps  74.568 Gbps  1.20% / 0.68%
>
> Assisted-by: LLM

I think Ilya already mentioned this earlier, but the LLM tag means you need to fill in the LLM model name you used.

The rest looks good to me.

//Eelco

> Signed-off-by: Wang Zhan <wang.zhan@smartx.com>
> ---
>
> v2:
> - add an empty line before netif_set_tso_max_size()
> - rebase net-next/main
> - cc all the maintainers
> v1: https://lore.kernel.org/20260910131635.780802-1-wang.zhan@smartx.com/
>
> ---
>  net/openvswitch/vport-internal_dev.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/net/openvswitch/vport-internal_dev.c b/net/openvswitch/vport-internal_dev.c
> index 125d310871e93..77a16d5ebd543 100644
> --- a/net/openvswitch/vport-internal_dev.c
> +++ b/net/openvswitch/vport-internal_dev.c
> @@ -117,6 +117,8 @@ static void do_setup(struct net_device *netdev)
>  	netdev->features |= NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX;
>  	netdev->hw_features = netdev->features;
>
> +	netif_set_tso_max_size(netdev, GSO_MAX_SIZE);
> +
>  	eth_hw_addr_random(netdev);
>  }
>
>
> base-commit: 87b80c2f6b05cad9f0ff9136709c62a0f59923e3
> -- 
> 2.47.3