Virtualization - Dec 2020 - [PATCH rfc 3/3] virtio-net: support transmit timestamp

On Wed, Dec 30, 2020 at 7:38 AM Richard Cochran
<richardcochran at gmail.com> wrote:
>
> On Mon, Dec 28, 2020 at 11:22:33AM -0500, Willem de Bruijn wrote:
> > From: Willem de Bruijn <willemb at google.com>
> >
> > Add optional delivery time (SO_TXTIME) offload for virtio-net.
> >
> > The Linux TCP/IP stack tries to avoid bursty transmission and network
> > congestion through pacing: computing an skb delivery time based on
> > congestion information. Userspace protocol implementations can achieve
> > the same with SO_TXTIME. This may also reduce scheduling jitter and
> > improve RTT estimation.
>
> This description is clear, but the Subject line is confusing.  It made
> me wonder whether this series is somehow about host/guest synchronization
> (but your comments do explain that that isn't the case).
>
> How about this instead?
>
>    virtio-net: support future packet transmit time
Yes, that's clearer. As is, this could easily be mistaken for
SOF_TIMESTAMPING_TX_*, which it is not. Will update, thanks.

Related terms already in use are SO_TXTIME, Earliest Delivery Time
(EDT) and Earliest TxTime First (ETF).

I should probably also s/TX_TSTAMP/TX_TIME/  in the code for the same reason.