Re: [PATCH] net/af_packet: add timestamp offloading support

[Stephen Hemminger <stephen@networkplumber.org>]

On Tue, 3 Sep 2024 13:43:06 +0200
Stefan Laesser <stefan.laesser@omicronenergy.com> wrote:

> Add the packet timestamp from TPACKET_V2 to the mbuf
> dynamic rx timestamp register if offload RTE_ETH_RX_OFFLOAD_TIMESTAMP
> is enabled.
> 
> TPACKET_V2 provides the timestamp with nanosecond resolution.
> 
> Signed-off-by: Stefan Laesser <stefan.laesser@omicronenergy.com>
> ---
>  .mailmap                                  |  1 +
>  doc/guides/nics/af_packet.rst             |  8 ++++--
>  drivers/net/af_packet/rte_eth_af_packet.c | 34 +++++++++++++++++++++--
>  3 files changed, 38 insertions(+), 5 deletions(-)

Adding timestamp is good, but it would be better if the timestamp
field was generic. The pcap PMD also has a timestamp, and pdump API
could/should use timestamp as well.

What makes sense is for there to be a standard dynamic field for
nanosecond resolution timestamp, and add a make sure that all drivers
use the same base  1/1/1970 same as Linux/Unix.  Also, having
standard helpers in ethdev for the conversion from TSC to NS would
help.