Hi, > -----Original Message----- > From: Andrew Rybchenko <andrew.rybche...@oktetlabs.ru> > Sent: Friday, July 15, 2022 8:14 PM > To: Thomas Monjalon <tho...@monjalon.net>; Ding, Xuan > <xuan.d...@intel.com>; ferruh.yi...@xilinx.com > Cc: m...@ashroe.eu; dev@dpdk.org; step...@networkplumber.org; > m...@smartsharesystems.com; Zhang, Qi Z <qi.z.zh...@intel.com>; > asek...@marvell.com; pbhagavat...@marvell.com; gr...@u256.net > Subject: Re: [PATCH] doc: announce header split deprecation > > On 7/14/22 16:25, Thomas Monjalon wrote: > > 14/07/2022 14:54, Ding, Xuan: > >> Hi, > >> > >> From: Thomas Monjalon <tho...@monjalon.net> > >>> 14/07/2022 07:50, Ding, Xuan: > >>>> From: Thomas Monjalon <tho...@monjalon.net> > >>>>> 23/05/2022 16:20, xuan.d...@intel.com: > >>>>>> From: Xuan Ding <xuan.d...@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.d...@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. > >>> > >>> What??? > >>> In old versions of your patch "ethdev: introduce protocol type based > >>> header split" > >>> you wrote: > >>> " > >>> A new proto field is introduced in the rte_eth_rxseg_split structure > >>> reserved field to specify header protocol type. > >>> With Rx offload flag RTE_ETH_RX_OFFLOAD_HEADER_SPLIT enabled and > >>> protocol type configured, PMD will split the ingress packets into > >>> two separate regions. > >>> " > >> > >> It has a long history... > >> It was corrected in v4 that RTE_ETH_RX_OFFLOAD_HEADER_SPLIT is used > >> to enable header split offload with the header size controlled using > "split_hdr_size". > >> But no single PMD actually supports > RTE_ETH_RX_OFFLOAD_HEADER_SPLIT for this purpose. > >> So we finally decide to deprecate this flag. > >> > >> http://patchwork.dpdk.org/project/dpdk/patch/20220402104109.472078- > 2- > >> wenxuanx...@intel.com/ > >> > >> In following series, I use RTE_ETH_RX_OFFLOAD_BUFFER_SPLIT instead. > >> It is for multi-segments packet split. And it still needs a "proto_hdr" > >> field > in rte_eth_rxmode to configure split location. > > > > I know this history because I was the one asking you to deprecate this. > > But it seems you didn't get the big picture. > > > >>>> Currently there are 2 acks, add more PMD maintainers to help review > >>>> this deprecation notice for header split, thanks a lot! > >>> > >>> I cannot say my feeling strong enough. > >> > >> So IMO the deprecation for header split is not relevant with buffer split. > But we can still clean the code. > >> Hope it make things clearer. > > > > They are almost the same features. > > So when deprecating one, it is important to mention what remains. > > If needed RTE_ETH_RX_OFFLOAD_BUFFER_SPLIT can still be used and it is > > configured per-queue, while RTE_ETH_RX_OFFLOAD_HEADER_SPLIT was > > configurable per-port. > > > > Andrew, Ferruh, do you agree to improve this deprecation notice by > > adding above information? > > +1 tt is definitely a very good idea.
Thanks, v2 is on the way. Regards, Xuan
