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From:   Luigi Rizzo <lrizzo@google.com>
Date:   Fri, 28 Feb 2020 02:56:01 -0800
Message-ID: <CAMOZA0JxgQ5Dvg7vvUk7TY8mx6Pd0raPXNBfbWup1JE1tr09fw@mail.gmail.com>
Subject: Re: [PATCH v3 net-next] netdev attribute to control xdpgeneric skb linearization
To:     =?UTF-8?B?VG9rZSBIw7hpbGFuZC1Kw7hyZ2Vuc2Vu?= <toke@redhat.com>
Cc:     netdev@vger.kernel.org, David Miller <davem@davemloft.net>,
        Jesper Dangaard Brouer <hawk@kernel.org>, sameehj@amazon.com,
        linux-kernel@vger.kernel.org
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On Fri, Feb 28, 2020 at 2:16 AM Toke H=C3=B8iland-J=C3=B8rgensen <toke@redh=
at.com> wrote:
>
> Luigi Rizzo <lrizzo@google.com> writes:
>
> > Add a netdevice flag to control skb linearization in generic xdp mode.
> >
> > The attribute can be modified through
> >       /sys/class/net/<DEVICE>/xdp_linearize
> > The default is 1 (on)
>
> Calling it just 'xdp_linearize' implies (to me) that it also affects
> driver-mode XDP. So maybe generic_xdp_linearize ?

done in v4, xdpgeneric_linearize for consistency

...

> > +Description:
> > +             boolean controlling whether skb should be linearized in
> > +             generic xdp. Defaults to true.
>
> Could you also add a few words explaining what the tradeoff here is?
> Something like: "turning this off can increase the performance of
> generic XDP at the cost of making the content of making the XDP program
> unable to access packet fragments after the first one"

done too in v4

thanks
luigi