From: Stanislav Fomichev <sdf@google•com>
To: Jesper Dangaard Brouer <jbrouer@redhat•com>
Cc: Willem de Bruijn <willemdebruijn.kernel@gmail•com>,
brouer@redhat•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, haoluo@google•com, jolsa@kernel•org,
kuba@kernel•org, toke@kernel•org, willemb@google•com,
dsahern@kernel•org, magnus.karlsson@intel•com, bjorn@kernel•org,
maciej.fijalkowski@intel•com, hawk@kernel•org,
netdev@vger•kernel.org, xdp-hints@xdp-project•net
Subject: Re: [RFC net-next v4 2/8] xsk: add TX timestamp and TX checksum offload support
Date: Thu, 27 Jul 2023 09:37:37 -0700 [thread overview]
Message-ID: <ZMKdUbsAGe318yCS@google.com> (raw)
In-Reply-To: <50fc375a-27a7-8b6a-3938-f9fcb4f85b06@redhat.com>
On 07/27, Jesper Dangaard Brouer wrote:
>
> On 26/07/2023 01.10, Willem de Bruijn wrote:
> > Stanislav Fomichev wrote:
> > > On 07/25, Willem de Bruijn wrote:
> > > > Stanislav Fomichev wrote:
> [...]
> > > > > +struct xsk_tx_metadata {
> > > > > + __u32 flags;
> > > > > +
> > > > > + /* XDP_TX_METADATA_CHECKSUM */
> > > > > +
> > > > > + /* Offset from desc->addr where checksumming should start. */
> > > > > + __u16 csum_start;
> > > > > + /* Offset from csum_start where checksum should be stored. */
> > > > > + __u16 csum_offset;
> > > > > +
> > > > > + /* XDP_TX_METADATA_TIMESTAMP */
> > > > > +
> > > > > + __u64 tx_timestamp;
> > > > > +};
> >>>
> > > > Is this structure easily extensible for future offloads,
> [...]
> >
> > Pacing offload is the other feature that comes to mind. That could
> > conceivably use the tx_timestamp field.
>
> I would really like to see hardware offload "pacing" or LaunchTime as
> hardware chips i210 and i225 calls it. I looked at the TX descriptor
> details for drivers igc (i225) and igb (i210), and documented my finding
> here[1], which should help with the code details if someone is motivated
> for implementing this (I know of people on xdp-hints list that wanted
> this LaunchTime feature).
>
> [1] https://github.com/xdp-project/xdp-project/blob/master/areas/tsn/code01_follow_qdisc_TSN_offload.org#tx-time-to-hardware-driver-igc
Nice!
> AFAIK this patchset uses struct xsk_tx_metadata as both TX and
> TX-Completion, right?. It would be "conceivable" to reuse tx_timestamp
> field, but it might be confusing for uAPI end-users. Maybe a union?
Sure, but do we add it later when we add launch time? For now, let's
figure out whether 'tx_timestamp' is the right name for the 'tx
completion timestamp' :-D Later on, we can union it with launch_time?
next prev parent reply other threads:[~2023-07-27 16:37 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-24 23:59 [RFC net-next v4 0/8] xsk: TX metadata Stanislav Fomichev
2023-07-24 23:59 ` [RFC net-next v4 1/8] xsk: Support XDP_TX_METADATA_LEN Stanislav Fomichev
2023-07-24 23:59 ` [RFC net-next v4 2/8] xsk: add TX timestamp and TX checksum offload support Stanislav Fomichev
2023-07-25 19:28 ` Simon Horman
2023-07-25 20:30 ` Stanislav Fomichev
2023-07-25 21:28 ` Jakub Kicinski
2023-07-25 22:40 ` Stanislav Fomichev
2023-07-26 7:47 ` Simon Horman
2023-07-25 20:54 ` Willem de Bruijn
2023-07-25 22:39 ` Stanislav Fomichev
2023-07-25 23:10 ` Willem de Bruijn
2023-07-25 23:48 ` Stanislav Fomichev
2023-07-27 14:11 ` Jesper Dangaard Brouer
2023-07-27 16:37 ` Stanislav Fomichev [this message]
2023-07-25 20:58 ` Willem de Bruijn
2023-07-28 11:56 ` Jesper Dangaard Brouer
2023-07-28 13:19 ` Willem de Bruijn
2023-07-26 19:25 ` [xdp-hints] " Jesper Dangaard Brouer
2023-07-26 21:25 ` Stanislav Fomichev
2023-07-27 13:50 ` Jesper Dangaard Brouer
2023-07-27 16:34 ` Stanislav Fomichev
2023-07-24 23:59 ` [RFC net-next v4 3/8] net/mlx5e: Implement AF_XDP TX timestamp and checksum offload Stanislav Fomichev
2023-07-24 23:59 ` [RFC net-next v4 4/8] tools: ynl: update netdev sample to dump xsk-features Stanislav Fomichev
2023-07-24 23:59 ` [RFC net-next v4 5/8] selftests/xsk: Support XDP_TX_METADATA_LEN Stanislav Fomichev
2023-07-24 23:59 ` [RFC net-next v4 6/8] selftests/bpf: Add csum helpers Stanislav Fomichev
2023-07-24 23:59 ` [RFC net-next v4 7/8] selftests/bpf: Add TX side to xdp_metadata Stanislav Fomichev
2023-07-24 23:59 ` [RFC net-next v4 8/8] selftests/bpf: Add TX side to xdp_hw_metadata Stanislav Fomichev
2023-07-25 20:59 ` Willem de Bruijn
2023-07-25 22:36 ` Stanislav Fomichev
2023-07-25 22:55 ` Willem de Bruijn
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