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From: Jakub Kicinski <kuba@kernel.org>
To: David Ahern <dsahern@gmail.com>
Cc: Alexander Lobakin <aleksander.lobakin@intel.com>,
	Larysa Zaremba <larysa.zaremba@intel.com>,
	bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net,
	andrii@kernel.org, martin.lau@linux.dev, song@kernel.org,
	yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org,
	sdf@google.com, haoluo@google.com, jolsa@kernel.org,
	Willem de Bruijn <willemb@google.com>,
	Jesper Dangaard Brouer <brouer@redhat.com>,
	Anatoly Burakov <anatoly.burakov@intel.com>,
	Alexander Lobakin <alexandr.lobakin@intel.com>,
	Magnus Karlsson <magnus.karlsson@gmail.com>,
	Maryam Tahhan <mtahhan@redhat.com>,
	xdp-hints@xdp-project.net, netdev@vger.kernel.org,
	Willem de Bruijn <willemdebruijn.kernel@gmail.com>,
	Alexei Starovoitov <alexei.starovoitov@gmail.com>,
	Simon Horman <simon.horman@corigine.com>,
	Tariq Toukan <tariqt@mellanox.com>,
	Saeed Mahameed <saeedm@mellanox.com>,
	Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Subject: [xdp-hints] Re: [RFC bpf-next v2 09/24] xdp: Add VLAN tag hint
Date: Thu, 5 Oct 2023 11:06:35 -0700	[thread overview]
Message-ID: <20231005110635.7020d23b@kernel.org> (raw)
In-Reply-To: <0be2e89e-8a08-e52c-fecd-3064262c2ecb@gmail.com>

On Thu, 5 Oct 2023 11:20:49 -0600 David Ahern wrote:
> > Every time I'm involved in conversations about NIC datapath host
> > interfaces I cringe at this stupid VLAN offload. Maybe I'm too
> > daft to understand it's amazing value but we just shift 2B from
> > the packet to the descriptor and then we have to worry about all
> > the corner cases that come from vlan stacking :(  
> 
> 4B (vlan tci + protocol).
> 
> VLAN stripping in S/W and pushing the header on Tx is measurable and
> does have a noticeable performance impact.
> 
> XDP programs need to co-exist with enabled offloads. If the tag is not
> stripped, XDP program needs to handle it. If the tag is stripped, the
> XDP program needs to access to the value.

Well, I thought I'd ask :) I'm not opposed.

But if either of you have the data on how much slower well-implemented
Rx stripping in the driver is than putting the info in the descriptor,
I'd be very interested.

Tx is a different situation.

  reply	other threads:[~2023-10-05 18:06 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-09-27  7:51 [xdp-hints] [RFC bpf-next v2 00/24] XDP metadata via kfuncs for ice + mlx5 Larysa Zaremba
2023-09-27  7:51 ` [xdp-hints] [RFC bpf-next v2 01/24] ice: make RX hash reading code more reusable Larysa Zaremba
2023-09-27  7:51 ` [xdp-hints] [RFC bpf-next v2 02/24] ice: make RX HW timestamp " Larysa Zaremba
2023-09-27  7:51 ` [xdp-hints] [RFC bpf-next v2 03/24] ice: make RX checksum checking " Larysa Zaremba
2023-09-27  7:51 ` [xdp-hints] [RFC bpf-next v2 04/24] ice: Make ptype internal to descriptor info processing Larysa Zaremba
2023-09-27  7:51 ` [xdp-hints] [RFC bpf-next v2 05/24] ice: Introduce ice_xdp_buff Larysa Zaremba
2023-09-27  7:51 ` [xdp-hints] [RFC bpf-next v2 06/24] ice: Support HW timestamp hint Larysa Zaremba
2023-09-27  7:51 ` [xdp-hints] [RFC bpf-next v2 07/24] ice: Support RX hash XDP hint Larysa Zaremba
2023-09-27  7:51 ` [xdp-hints] [RFC bpf-next v2 08/24] ice: Support XDP hints in AF_XDP ZC mode Larysa Zaremba
2023-09-27  7:51 ` [xdp-hints] [RFC bpf-next v2 09/24] xdp: Add VLAN tag hint Larysa Zaremba
2023-10-03 12:35   ` [xdp-hints] " Jakub Kicinski
2023-10-03 13:09     ` Alexander Lobakin
2023-10-04 18:08       ` Jakub Kicinski
2023-10-05 16:58         ` Alexander Lobakin
2023-10-05 17:16           ` Jakub Kicinski
2023-10-05 17:20             ` David Ahern
2023-10-05 18:06               ` Jakub Kicinski [this message]
2023-09-27  7:51 ` [xdp-hints] [RFC bpf-next v2 10/24] ice: Implement " Larysa Zaremba
2023-09-27  7:51 ` [xdp-hints] [RFC bpf-next v2 11/24] ice: use VLAN proto from ring packet context in skb path Larysa Zaremba
2023-09-27  7:51 ` [xdp-hints] [RFC bpf-next v2 12/24] xdp: Add checksum hint Larysa Zaremba
2023-09-27  7:51 ` [xdp-hints] [RFC bpf-next v2 13/24] ice: Implement " Larysa Zaremba
2023-09-27  7:51 ` [xdp-hints] [RFC bpf-next v2 14/24] ice: put XDP meta sources assignment under a static key condition Larysa Zaremba
2023-09-27  7:51 ` [xdp-hints] [RFC bpf-next v2 15/24] selftests/bpf: Allow VLAN packets in xdp_hw_metadata Larysa Zaremba
2023-09-27  7:51 ` [xdp-hints] [RFC bpf-next v2 16/24] net, xdp: allow metadata > 32 Larysa Zaremba
2023-09-27  7:51 ` [xdp-hints] [RFC bpf-next v2 17/24] selftests/bpf: Add flags and new hints to xdp_hw_metadata Larysa Zaremba
2023-09-27  7:51 ` [xdp-hints] [RFC bpf-next v2 18/24] veth: Implement VLAN tag and checksum XDP hint Larysa Zaremba
2023-09-27  7:51 ` [xdp-hints] [RFC bpf-next v2 19/24] net: make vlan_get_tag() return -ENODATA instead of -EINVAL Larysa Zaremba
2023-09-27  7:51 ` [xdp-hints] [RFC bpf-next v2 20/24] selftests/bpf: Use AF_INET for TX in xdp_metadata Larysa Zaremba
2023-09-27  7:51 ` [xdp-hints] [RFC bpf-next v2 21/24] selftests/bpf: Check VLAN tag and proto " Larysa Zaremba
2023-09-27  7:51 ` [xdp-hints] [RFC bpf-next v2 22/24] selftests/bpf: check checksum state " Larysa Zaremba
2023-09-27  7:51 ` [xdp-hints] [RFC bpf-next v2 23/24] mlx5: implement VLAN tag XDP hint Larysa Zaremba
2023-09-27  7:51 ` [xdp-hints] [RFC bpf-next v2 24/24] mlx5: implement RX checksum " Larysa Zaremba

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