From: Larysa Zaremba <larysa.zaremba@intel.com>
To: John Fastabend <john.fastabend@gmail.com>
Cc: bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net,
andrii@kernel.org, martin.lau@linux.dev, song@kernel.org,
yhs@fb.com, kpsingh@kernel.org, sdf@google.com,
haoluo@google.com, jolsa@kernel.org,
David Ahern <dsahern@gmail.com>, Jakub Kicinski <kuba@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,
Aleksander Lobakin <aleksander.lobakin@intel.com>
Subject: [xdp-hints] Re: [PATCH bpf-next v2 15/20] net, xdp: allow metadata > 32
Date: Thu, 6 Jul 2023 16:51:22 +0200 [thread overview]
Message-ID: <ZKbU6qaPUN/gPY9t@lincoln> (raw)
In-Reply-To: <64a3386623163_65205208fe@john.notmuch>
On Mon, Jul 03, 2023 at 02:06:46PM -0700, John Fastabend wrote:
> Larysa Zaremba wrote:
> > From: Aleksander Lobakin <aleksander.lobakin@intel.com>
> >
> > When using XDP hints, metadata sometimes has to be much bigger
> > than 32 bytes. Relax the restriction, allow metadata larger than 32 bytes
> > and make __skb_metadata_differs() work with bigger lengths.
> >
> > Now size of metadata is only limited by the fact it is stored as u8
> > in skb_shared_info, so maximum possible value is 255. Other important
> > conditions, such as having enough space for xdp_frame building, are already
> > checked in bpf_xdp_adjust_meta().
> >
> > The requirement of having its length aligned to 4 bytes is still
> > valid.
> >
> > Signed-off-by: Aleksander Lobakin <aleksander.lobakin@intel.com>
> > Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
> > ---
> > include/linux/skbuff.h | 13 ++++++++-----
> > include/net/xdp.h | 7 ++++++-
> > 2 files changed, 14 insertions(+), 6 deletions(-)
> >
> > diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
> > index 91ed66952580..cd49cdd71019 100644
> > --- a/include/linux/skbuff.h
> > +++ b/include/linux/skbuff.h
> > @@ -4209,10 +4209,13 @@ static inline bool __skb_metadata_differs(const struct sk_buff *skb_a,
> > {
> > const void *a = skb_metadata_end(skb_a);
> > const void *b = skb_metadata_end(skb_b);
> > - /* Using more efficient varaiant than plain call to memcmp(). */
> > -#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
>
> Why are we removing the ifdef here? Its adding a runtime 'if' when its not
> necessary. I would keep the ifdef and simply add the default case
> in the switch.
Seems like Alex has missed your message, but we discussed this with him before,
so I know the answer: Compiler will 100% convert it into a compile-time 'if' and
this looks nicer than preprocessor condition.
next prev parent reply other threads:[~2023-07-06 14:55 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-03 18:12 [xdp-hints] [PATCH bpf-next v2 00/20] XDP metadata via kfuncs for ice Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 01/20] ice: make RX hash reading code more reusable Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 02/20] ice: make RX HW timestamp " Larysa Zaremba
2023-07-04 10:04 ` [xdp-hints] " Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 03/20] ice: make RX checksum checking " Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 04/20] ice: Make ptype internal to descriptor info processing Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 05/20] ice: Introduce ice_xdp_buff Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 06/20] ice: Support HW timestamp hint Larysa Zaremba
2023-07-05 17:30 ` [xdp-hints] " Stanislav Fomichev
2023-07-06 14:22 ` Larysa Zaremba
2023-07-06 16:39 ` Stanislav Fomichev
2023-07-10 15:49 ` Larysa Zaremba
2023-07-10 18:12 ` Stanislav Fomichev
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 07/20] ice: Support RX hash XDP hint Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 08/20] ice: Support XDP hints in AF_XDP ZC mode Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 09/20] xdp: Add VLAN tag hint Larysa Zaremba
2023-07-03 20:15 ` [xdp-hints] " John Fastabend
2023-07-04 8:23 ` Larysa Zaremba
2023-07-04 10:23 ` Jesper Dangaard Brouer
2023-07-04 11:02 ` Larysa Zaremba
2023-07-04 14:18 ` Jesper Dangaard Brouer
2023-07-06 14:46 ` Larysa Zaremba
2023-07-07 13:57 ` Jesper Dangaard Brouer
2023-07-07 17:58 ` Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 10/20] ice: Implement " Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 11/20] ice: use VLAN proto from ring packet context in skb path Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 12/20] xdp: Add checksum level hint Larysa Zaremba
2023-07-03 20:38 ` [xdp-hints] " John Fastabend
2023-07-04 9:24 ` Larysa Zaremba
2023-07-04 10:39 ` Jesper Dangaard Brouer
2023-07-04 11:19 ` Larysa Zaremba
2023-07-06 5:50 ` John Fastabend
2023-07-06 9:04 ` Jesper Dangaard Brouer
2023-07-06 12:38 ` Larysa Zaremba
2023-07-06 12:49 ` Larysa Zaremba
2023-07-10 16:58 ` Alexander Lobakin
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 13/20] ice: Implement " Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 14/20] selftests/bpf: Allow VLAN packets in xdp_hw_metadata Larysa Zaremba
2023-07-05 17:31 ` [xdp-hints] " Stanislav Fomichev
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 15/20] net, xdp: allow metadata > 32 Larysa Zaremba
2023-07-03 21:06 ` [xdp-hints] " John Fastabend
2023-07-06 14:51 ` Larysa Zaremba [this message]
2023-07-10 14:01 ` Alexander Lobakin
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 16/20] selftests/bpf: Add flags and new hints to xdp_hw_metadata Larysa Zaremba
2023-07-04 11:03 ` [xdp-hints] " Jesper Dangaard Brouer
2023-07-04 11:04 ` Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 17/20] veth: Implement VLAN tag and checksum level XDP hint Larysa Zaremba
2023-07-05 17:25 ` [xdp-hints] " Stanislav Fomichev
2023-07-06 9:57 ` Jesper Dangaard Brouer
2023-07-06 10:15 ` Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 18/20] selftests/bpf: Use AF_INET for TX in xdp_metadata Larysa Zaremba
2023-07-05 17:39 ` [xdp-hints] " Stanislav Fomichev
2023-07-06 14:11 ` Larysa Zaremba
2023-07-06 17:25 ` Stanislav Fomichev
2023-07-06 17:27 ` Stanislav Fomichev
2023-07-07 8:33 ` Larysa Zaremba
2023-07-07 16:49 ` Stanislav Fomichev
2023-07-07 16:58 ` Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 19/20] selftests/bpf: Check VLAN tag and proto " Larysa Zaremba
2023-07-05 17:41 ` [xdp-hints] " Stanislav Fomichev
2023-07-06 10:10 ` Jesper Dangaard Brouer
2023-07-06 10:13 ` Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 20/20] selftests/bpf: check checksum level " Larysa Zaremba
2023-07-05 17:41 ` [xdp-hints] " Stanislav Fomichev
2023-07-06 10:25 ` Jesper Dangaard Brouer
2023-07-06 12:02 ` Larysa Zaremba
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