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From: David Marchand <david.marchand@redhat.com>
To: Ferruh Yigit <ferruh.yigit@intel.com>, Igor Ryzhov <iryzhov@nfware.com>
Cc: dev <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH] kni: add ability to set min/max MTU
Date: Wed, 16 Oct 2019 16:47:10 +0200	[thread overview]
Message-ID: <CAJFAV8zW75=CT8sch=eP7nvk7ipbXt6V4C4_8x=a+5z0OqhQhQ@mail.gmail.com> (raw)
In-Reply-To: <CAJFAV8x3=Cqs5G2245iNQs1fMzyQjEtgEXhhOatzsQge5a4icQ@mail.gmail.com>

On Wed, Oct 16, 2019 at 12:55 PM David Marchand
<david.marchand@redhat.com> wrote:
>
> On Wed, Oct 16, 2019 at 12:43 PM Ferruh Yigit <ferruh.yigit@intel.com> wrote:
> >
> > On 10/16/2019 7:40 AM, David Marchand wrote:
> > > On Fri, Oct 11, 2019 at 6:16 PM Ferruh Yigit <ferruh.yigit@intel.com> wrote:
> > >>
> > >> On 9/19/2019 12:22 PM, Igor Ryzhov wrote:
> > >>> Starting with kernel version 4.10, there are new min/max MTU values in
> > >>> net_device structure, which are set to ETH_MIN_MTU and ETH_DATA_LEN by
> > >>> default. We should be able to change these values to allow MTU more than
> > >>> 1500 to be set on KNI.
> > >>>
> > >>> Signed-off-by: Igor Ryzhov <iryzhov@nfware.com>
> > >>
> > >> Acked-by: Ferruh Yigit <ferruh.yigit@intel.com>
> > >
> > > I intend to change the title as "kni: fix mtu setting with kernels >= 4.10".
> > > Does it sound ok to you?
> >
> > I am not quite sure it is a fix, this patch enables application to pass min/max
> > MTU values for kni netdev but existing code is not doing anything wrong.
>
> To me, starting 4.10, we can't set the mtu to something greater than
> 1500 on a kni netdev, since netdev uses the ETH_DATA_LEN default value
> and will refuse a bigger mtu before even calling the change mtu ndo.
> Did I understand something wrong?

- As discussed on irc and after looking deeper into the code.
The support for jumbo frames was already present and should be working
with the current code.
So I agree this does not qualify as a fix, sorry for the noise.

- On the other hand, we could refactor this patch to make use of/merge
with the existing HAVE_MAX_MTU_PARAM pre-existing macro without
introducing a new one.

- The commit title/log is still a bit cryptic to me, in which case
would an application pass a min_mtu/max_mtu?


Thanks.
-- 
David Marchand


  reply	other threads:[~2019-10-16 14:47 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-19 11:22 Igor Ryzhov
2019-10-11 16:16 ` Ferruh Yigit
2019-10-16  6:40   ` David Marchand
2019-10-16 10:43     ` Ferruh Yigit
2019-10-16 10:55       ` David Marchand
2019-10-16 14:47         ` David Marchand [this message]
2019-10-16 14:59           ` Ferruh Yigit
2019-10-25 18:30 ` [dpdk-dev] [PATCH v2] " Ferruh Yigit
2019-10-25 18:32   ` Ferruh Yigit
2019-10-27 10:12   ` David Marchand
2019-10-27 19:56     ` Igor Ryzhov

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