XDP hardware hints discussion mail archive
 help / color / mirror / Atom feed
From: Jesper Dangaard Brouer <jbrouer@redhat.com>
To: Willem de Bruijn <willemdebruijn.kernel@gmail.com>,
	Stanislav Fomichev <sdf@google.com>
Cc: 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: [xdp-hints] Re: [RFC net-next v4 2/8] xsk: add TX timestamp and TX checksum offload support
Date: Thu, 27 Jul 2023 16:11:08 +0200	[thread overview]
Message-ID: <50fc375a-27a7-8b6a-3938-f9fcb4f85b06@redhat.com> (raw)
In-Reply-To: <64c056686b527_3a4d294e6@willemb.c.googlers.com.notmuch>


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

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?

--Jesper


  parent reply	other threads:[~2023-07-27 14:11 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-07-24 23:59 [xdp-hints] [RFC net-next v4 0/8] xsk: TX metadata Stanislav Fomichev
2023-07-24 23:59 ` [xdp-hints] [RFC net-next v4 1/8] xsk: Support XDP_TX_METADATA_LEN Stanislav Fomichev
2023-07-24 23:59 ` [xdp-hints] [RFC net-next v4 2/8] xsk: add TX timestamp and TX checksum offload support Stanislav Fomichev
2023-07-25 19:28   ` [xdp-hints] " 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 [this message]
2023-07-27 16:37           ` Stanislav Fomichev
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   ` 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 ` [xdp-hints] [RFC net-next v4 3/8] net/mlx5e: Implement AF_XDP TX timestamp and checksum offload Stanislav Fomichev
2023-07-24 23:59 ` [xdp-hints] [RFC net-next v4 4/8] tools: ynl: update netdev sample to dump xsk-features Stanislav Fomichev
2023-07-24 23:59 ` [xdp-hints] [RFC net-next v4 5/8] selftests/xsk: Support XDP_TX_METADATA_LEN Stanislav Fomichev
2023-07-24 23:59 ` [xdp-hints] [RFC net-next v4 6/8] selftests/bpf: Add csum helpers Stanislav Fomichev
2023-07-24 23:59 ` [xdp-hints] [RFC net-next v4 7/8] selftests/bpf: Add TX side to xdp_metadata Stanislav Fomichev
2023-07-24 23:59 ` [xdp-hints] [RFC net-next v4 8/8] selftests/bpf: Add TX side to xdp_hw_metadata Stanislav Fomichev
2023-07-25 20:59   ` [xdp-hints] " Willem de Bruijn
2023-07-25 22:36     ` Stanislav Fomichev
2023-07-25 22:55       ` Willem de Bruijn

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: https://lists.xdp-project.net/postorius/lists/xdp-hints.xdp-project.net/

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=50fc375a-27a7-8b6a-3938-f9fcb4f85b06@redhat.com \
    --to=jbrouer@redhat.com \
    --cc=andrii@kernel.org \
    --cc=ast@kernel.org \
    --cc=bjorn@kernel.org \
    --cc=bpf@vger.kernel.org \
    --cc=brouer@redhat.com \
    --cc=daniel@iogearbox.net \
    --cc=dsahern@kernel.org \
    --cc=haoluo@google.com \
    --cc=hawk@kernel.org \
    --cc=john.fastabend@gmail.com \
    --cc=jolsa@kernel.org \
    --cc=kpsingh@kernel.org \
    --cc=kuba@kernel.org \
    --cc=maciej.fijalkowski@intel.com \
    --cc=magnus.karlsson@intel.com \
    --cc=martin.lau@linux.dev \
    --cc=netdev@vger.kernel.org \
    --cc=sdf@google.com \
    --cc=song@kernel.org \
    --cc=toke@kernel.org \
    --cc=willemb@google.com \
    --cc=willemdebruijn.kernel@gmail.com \
    --cc=xdp-hints@xdp-project.net \
    --cc=yhs@fb.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox