[dpdk-dev] [patch v3] doc: announce API change in ethdev offload flags

Ananyev, Konstantin konstantin.ananyev at intel.com
Thu Aug 8 12:08:48 CEST 2019


Hi Jerin,

> >
> > Hi guys,
> >
> > >
> > > From: Pavan Nikhilesh <pbhagavatula at marvell.com>
> > >
> > > Add new offload flags ``DEV_RX_OFFLOAD_PTYPE``,
> > ``DEV_RX_OFFLOAD_RSS``
> > > and ``DEV_RX_OFFLOAD_FLOW_MARK``.
> > >
> > > Signed-off-by: Pavan Nikhilesh <pbhagavatula at marvell.com>
> > > Acked-by: Andrew Rybchenko <arybchenko at solarflare.com>
> > > Acked-by: Jerin Jacob <jerinj at marvell.com>
> > > ---
> > >  v3 Changes:
> > >  - DEV_RX_OFFLOAD_RSS -> DEV_RX_OFFLOAD_RSS_HASH (anndrew).
> > >
> > >  v2 Changes:
> > >  - Reword for clarity.
> > >
> > >  doc/guides/rel_notes/deprecation.rst | 13 +++++++++++++
> > >  1 file changed, 13 insertions(+)
> > >
> > > diff --git a/doc/guides/rel_notes/deprecation.rst
> > > b/doc/guides/rel_notes/deprecation.rst
> > > index 37b8592b6..056c5709f 100644
> > > --- a/doc/guides/rel_notes/deprecation.rst
> > > +++ b/doc/guides/rel_notes/deprecation.rst
> > > @@ -78,3 +78,16 @@ Deprecation Notices
> > >    to set new power environment if power environment was already
> > initialized.
> > >    In this case the function will return -1 unless the environment is unset
> > first
> > >    (using ``rte_power_unset_env``). Other function usage scenarios will not
> > change.
> > > +
> > > +* ethdev: New offload flags ``DEV_RX_OFFLOAD_PTYPE``,
> > > +``DEV_RX_OFFLOAD_RSS_HASH``
> > > +  and ``DEV_RX_OFFLOAD_FLOW_MARK`` will be added in 19.11.
> >
> > One question about DEV_RX_OFFLOAD_PTYPE:
> > Does it mean that new ol_flags value (PKT_RX_PTYPE) will be introduced to
> > indicate that mbuf.packet_type value is set?
> > Or PMD will have to set  mbuf.packet_type to zero, when
> > DEV_RX_OFFLOAD_PTYPE was not enabled by user?
> 
> I was thinking when DEV_RX_OFFLOAD_PTYPE is set
> - mbuf.packet_type will be valid and mbuf.packet_type will have parsed packet type.
> If not set
> - mbuf.packet_type can be anything application should not use mbuf.packet_type field.

But in that case, we do need a new value for ol_flags, PKT_RX_PTYPE or so, right?

> 
> This will avoid writes 0 to mbuf.packet_type and packet_type parsing if offload is not set.
> 
> 
> > If so, what is the advantage?
> > Again in that case, would it be more plausible to introduce something like:
> > rte_eth_dev_set_supported_ptypes(uint16_t port_id, uint32_t
> > ptype_mask); instead of DEV_RX_OFFLOAD_PTYPE?
> 
> Any scheme is fine where we can skip the  write 0 to mbuf.packet_type and packet_type parsing
> If application is NOT interested in packet_type.
> 
> > Konstantin
> >
> > > +  This will allow application to enable or disable PMDs from updating
> > > + ``rte_mbuf`` fields ``rte_mbuf::packet_type``,
> > > + ``rte_mbuf::hash::rss`` and  ``rte_mbuf::hash::fdir`` respectively.
> > > +  This scheme will allow PMDs to avoid writes to ``rte_mbuf`` fields
> > > + on Rx and  thereby improve Rx performance if application wishes do so.
> > > +  In 19.11 PMDs will still update the fields even when the offloads
> > > + are not  enabled.
> > > +  The exact semantics of the flags will be worked out later either by
> > > + making  them negative offloads to avoid application change or
> > > + positive offload to  align with existing offload flag semantics.
> > > --
> > > 2.17.1



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