From: "Toke Høiland-Jørgensen" <toke@redhat.com>
To: Luigi Rizzo <lrizzo@google.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>,
netdev@vger.kernel.org, Jesper Dangaard Brouer <hawk@kernel.org>,
"David S. Miller" <davem@davemloft.net>,
sameehj@amazon.com
Subject: Re: [PATCH] net-xdp: netdev attribute to control xdpgeneric skb linearization
Date: Fri, 24 Jan 2020 22:27:58 +0100 [thread overview]
Message-ID: <87a76cfstd.fsf@toke.dk> (raw)
In-Reply-To: <CAMOZA0KZOyEjJj3N7WQNRYi+n91UKkWihQRjxdrbCs9JdM5cbg@mail.gmail.com>
Luigi Rizzo <lrizzo@google.com> writes:
> On Fri, Jan 24, 2020 at 7:31 AM Toke Høiland-Jørgensen <toke@redhat.com> wrote:
>>
>> Luigi Rizzo <lrizzo@google.com> writes:
>>
> ...
>> > My motivation for this change is that enforcing those guarantees has
>> > significant cost (even for native xdp in the cases I mentioned - mtu >
>> > 1 page, hw LRO, header split), and this is an interim solution to make
>> > generic skb usable without too much penalty.
>>
>> Sure, that part I understand; I just don't like that this "interim"
>> solution makes generic and native XDP diverge further in their
>> semantics...
>
> As a matter of fact I think it would make full sense to use the same approach
> to control whether native xdp should pay the price converting to linear buffers
> when the hw cannot guarantee that.
>
> To me this seems to be a case of "perfect is enemy of good":..
Hmm, I can kinda see your point (now that I've actually grok'ed how the
length works with skbs and generic XDP :)). I would still worry that
only having the header there would lead some XDP programs to just
silently fail. But on the other hand, this is opt-in... so IDK - maybe
this is fine to merge as-is, and leave improvements for later?
-Toke
next prev parent reply other threads:[~2020-01-24 21:28 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-22 20:32 [PATCH] net-xdp: netdev attribute to control xdpgeneric skb linearization Luigi Rizzo
2020-01-23 9:53 ` Toke Høiland-Jørgensen
2020-01-23 15:48 ` Daniel Borkmann
2020-01-23 16:14 ` Toke Høiland-Jørgensen
2020-01-23 17:30 ` Luigi Rizzo
2020-01-23 18:01 ` Toke Høiland-Jørgensen
2020-01-23 18:06 ` Luigi Rizzo
2020-01-23 21:36 ` Daniel Borkmann
2020-01-24 9:57 ` Toke Høiland-Jørgensen
2020-01-24 14:31 ` Luigi Rizzo
2020-01-24 15:30 ` Toke Høiland-Jørgensen
2020-01-24 17:15 ` Luigi Rizzo
2020-01-24 21:27 ` Toke Høiland-Jørgensen [this message]
2020-02-05 15:36 ` Luigi Rizzo
[not found] ` <CA+hQ2+hnqifXzyHjjc5TXJmJz_EVCbuF6vGchKjaWccfK2ZA4g@mail.gmail.com>
2020-02-05 15:55 ` Toke Høiland-Jørgensen
2020-01-23 17:25 ` Luigi Rizzo
2020-01-23 18:00 ` Toke Høiland-Jørgensen
2020-01-23 18:11 ` Luigi Rizzo
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