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Miller" , Eric Dumazet , Simon Horman , Michael Chan , Pavan Chebbi , Andrew Lunn , Tony Nguyen , Przemek Kitszel , Saeed Mahameed , Leon Romanovsky , Tariq Toukan , Mark Bloch , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , Stanislav Fomichev , intel-wired-lan@lists.osuosl.org, bpf@vger.kernel.org, kernel-team@cloudflare.com Subject: Re: [Intel-wired-lan] [PATCH net-next 00/10] Call skb_metadata_set when skb->data points past metadata In-Reply-To: <36deb505-1c82-4339-bb44-f72f9eacb0ac@redhat.com> (Paolo Abeni's message of "Tue, 13 Jan 2026 13:09:45 +0100") References: <20260110-skb-meta-fixup-skb_metadata_set-calls-v1-0-1047878ed1b0@cloudflare.com> <20260112190856.3ff91f8d@kernel.org> <36deb505-1c82-4339-bb44-f72f9eacb0ac@redhat.com> Date: Tue, 13 Jan 2026 13:40:46 +0100 Message-ID: <877btlwur5.fsf@cloudflare.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On Tue, Jan 13, 2026 at 01:09 PM +01, Paolo Abeni wrote: > IIRC, at early MPTCP impl time, Eric suggested increasing struct sk_buff > size as an alternative to the mptcp skb extension, leaving the added > trailing part uninitialized when the sk_buff is allocated. > > If skb extensions usage become so ubicuos they are basically allocated > for each packet, the total skb extension is kept under strict control > and remains reasonable (assuming it is :), perhaps we could consider > revisiting the above mentioned approach? I've been thinking the same thing. Great to hear that this idea is not new. FWIW, in our use cases we'd want to attach metadata to the first packet of new TCP/QUIC flow, and ocassionally to sampled skbs for tracing.