Re: [Intel-wired-lan] [PATCH v2 net] ixgbe: allow to increase MTU to some extent with XDP enabled

[Jason Xing]

On Wed, Feb 1, 2023 at 7:15 PM Alexander Lobakin
<alexandr.lobakin@xxxxxxxxx> wrote:
>
> From: Jason Xing <kerneljasonxing@xxxxxxxxx>
> Date: Tue, 31 Jan 2023 19:23:59 +0800
>
> > On Tue, Jan 31, 2023 at 7:08 PM Alexander Lobakin
> > <alexandr.lobakin@xxxxxxxxx> wrote:
>
> [...]
>
> >>>> You said in this thread that you've done several tests - what were they?
> >>>
> >>> Tests against XDP are running on the server side when MTU varies from
> >>> 1500 to 3050 (not including ETH_HLEN, ETH_FCS_LEN and VLAN_HLEN) for a
> >>
> >
> >> BTW, if ixgbe allows you to set MTU of 3050, it needs to be fixed. Intel
> >> drivers at some point didn't include the second VLAN tag into account,
> >
> > Yes, I noticed that.
> >
> > It should be like "int new_frame_size = new_mtu + ETH_HLEN +
> > ETH_FCS_LEN + (VLAN_HLEN * 2)" instead of only one VLAN_HLEN, which is
> > used to compute real size in ixgbe_change_mtu() function.
> > I'm wondering if I could submit another patch to fix the issue you
> > mentioned because the current patch tells a different issue. Does it
> > make sense?
>
> Yes, please send as a separate patch. It's somewhat related to the
> topic, but better to keep commits atomic.

Hi Alexander,

I'm not sure if I should wait for the current patch to get reviewed,
then I'll write the vlan related patch we talked about based on the
current patch?

Thanks,
Jason

>
> >
> > If you're available, please help me review the v3 patch I've already
> > sent to the mailing-list. Thanks anyway.
> > The Link is https://lore.kernel.org/lkml/20230131032357.34029-1-kerneljasonxing@xxxxxxxxx/
> > .
> >
> > Thanks,
> > Jason
>
> Thanks,
> Olek
>