RE: [PATCH] doc: announce header split deprecation

["Ding, Xuan" <xuan.ding@intel.com>]

Hi,

> -----Original Message-----
> From: Thomas Monjalon <thomas@monjalon.net>
> Sent: 2022年7月13日 17:50
> To: Ding, Xuan <xuan.ding@intel.com>
> Cc: andrew.rybchenko@oktetlabs.ru; mdr@ashroe.eu; dev@dpdk.org;
> stephen@networkplumber.org; mb@smartsharesystems.com; dev@dpdk.org
> Subject: Re: [PATCH] doc: announce header split deprecation
> 
> 23/05/2022 16:20, xuan.ding@intel.com:
> > From: Xuan Ding <xuan.ding@intel.com>
> >
> > RTE_ETH_RX_OFFLOAD_HEADER_SPLIT offload was introduced some time
> ago
> > to substitute bit-field header_split in struct rte_eth_rxmode. It
> > allows to enable header split offload with the header size controlled
> > using split_hdr_size in the same structure.
> >
> > Right now, no single PMD actually supports
> > RTE_ETH_RX_OFFLOAD_HEADER_SPLIT with above definition. Many examples
> > and test apps initialize the field to 0 explicitly. The most of
> > drivers simply ignore split_hdr_size since the offload is not advertised, but
> some double-check that its value is 0.
> >
> > So the RTE_ETH_RX_OFFLOAD_HEADER_SPLIT and split_header_size field
> > will be removed in DPDK 22.11.
> >
> > Signed-off-by: Xuan Ding <xuan.ding@intel.com>
> > ---
> >  doc/guides/rel_notes/deprecation.rst | 4 ++++
> >  1 file changed, 4 insertions(+)
> >
> > diff --git a/doc/guides/rel_notes/deprecation.rst
> > b/doc/guides/rel_notes/deprecation.rst
> > index 4e5b23c53d..b8114f29ed 100644
> > --- a/doc/guides/rel_notes/deprecation.rst
> > +++ b/doc/guides/rel_notes/deprecation.rst
> > @@ -125,3 +125,7 @@ Deprecation Notices
> >    applications should be updated to use the ``dmadev`` library instead,
> >    with the underlying HW-functionality being provided by the ``ioat`` or
> >    ``idxd`` dma drivers
> > +
> > +* ethdev: After bit-field header split was removed, the
> > +``RTE_ETH_RX_OFFLOAD_HEADER_SPLIT``
> > +offload and the ``split_hdr_size`` field in structure
> > +``rte_eth_rxmode`` to enable header split offload are not supported in any
> PMDs. They will be removed in DPDK 22.11.
> 
> It would have been good to talk about rte_eth_rxseg_split which is similar and
> configured per-queue.
 
Thanks for your suggestion.

But I'm a little confused, are you referring that I need to involve protocol based buffer split?
About the deprecation of header split, I haven't realized its connection to rte_eth_rxseg_split.

Currently there are 2 acks, add more PMD maintainers to help review this deprecation notice
for header split, thanks a lot!

Regards,
Xuan


>