> -----Original Message----- > From: Ananyev, Konstantin <konstantin.anan...@intel.com> > Sent: Thursday, August 8, 2019 4:04 PM > To: Jerin Jacob Kollanukkaran <jer...@marvell.com>; Pavan Nikhilesh > Bhagavatula <pbhagavat...@marvell.com>; step...@networkplumber.org; > arybche...@solarflare.com; hemant.agra...@nxp.com; > tho...@monjalon.net; Yigit, Ferruh <ferruh.yi...@intel.com>; Richardson, > Bruce <bruce.richard...@intel.com>; Neil Horman > <nhor...@tuxdriver.com>; Mcnamara, John <john.mcnam...@intel.com>; > Kovacevic, Marko <marko.kovace...@intel.com> > Cc: dev@dpdk.org > Subject: [EXT] RE: [dpdk-dev] [patch v3] doc: announce API change in ethdev > offload flags > > External Email > > ---------------------------------------------------------------------- > > > > -----Original Message----- > > From: Jerin Jacob Kollanukkaran [mailto:jer...@marvell.com] > > Sent: Thursday, August 8, 2019 11:23 AM > > To: Ananyev, Konstantin <konstantin.anan...@intel.com>; Pavan > > Nikhilesh Bhagavatula <pbhagavat...@marvell.com>; > > step...@networkplumber.org; arybche...@solarflare.com; > > hemant.agra...@nxp.com; tho...@monjalon.net; Yigit, Ferruh > > <ferruh.yi...@intel.com>; Richardson, Bruce > > <bruce.richard...@intel.com>; Neil Horman <nhor...@tuxdriver.com>; > > Mcnamara, John <john.mcnam...@intel.com>; Kovacevic, Marko > > <marko.kovace...@intel.com> > > Cc: dev@dpdk.org > > Subject: RE: [dpdk-dev] [patch v3] doc: announce API change in ethdev > > offload flags > > > > > -----Original Message----- > > > From: Ananyev, Konstantin <konstantin.anan...@intel.com> > > > Sent: Thursday, August 8, 2019 3:39 PM > > > To: Jerin Jacob Kollanukkaran <jer...@marvell.com>; Pavan Nikhilesh > > > Bhagavatula <pbhagavat...@marvell.com>; > step...@networkplumber.org; > > > arybche...@solarflare.com; hemant.agra...@nxp.com; > > > tho...@monjalon.net; Yigit, Ferruh <ferruh.yi...@intel.com>; > > > Richardson, Bruce <bruce.richard...@intel.com>; Neil Horman > > > <nhor...@tuxdriver.com>; Mcnamara, John > <john.mcnam...@intel.com>; > > > Kovacevic, Marko <marko.kovace...@intel.com> > > > Cc: dev@dpdk.org > > > Subject: [EXT] RE: [dpdk-dev] [patch v3] doc: announce API change in > > > ethdev offload flags > > > > > > External Email > > > > > > -------------------------------------------------------------------- > > > -- > > > Hi Jerin, > > > > Hi Konstantin, > > > > > > > > > > > > > > > > > Hi guys, > > > > > > > > > > > > > > > > > From: Pavan Nikhilesh <pbhagavat...@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 <pbhagavat...@marvell.com> > > > > > > Acked-by: Andrew Rybchenko <arybche...@solarflare.com> > > > > > > Acked-by: Jerin Jacob <jer...@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? > > > > Since application has two knobs rte_eth_dev_get_supported_ptypes() and > > DEV_RX_OFFLOAD_PTYPE. We may not need to new ol_flags for this > change. Right? > > i.e if application sets the DEV_RX_OFFLOAD_PTYPE, The application will > > get the parsed ptypes by the driver(= > rte_eth_dev_get_supported_ptypes()). > > So there is no scope ambiguity. Right? > > I still think there is: > Imagine user has 2 eth devices, one does support DEV_RX_OFFLOAD_PTYPE, > second doesn't. Now he has a mix of packets from both devices, that you > want t process. > How would he figure out for which of them ptype values are valid, and for > each are not? > Trace back from what port he has received them? > Not very convenient, and not always possible.
I thought so. But in that case, application can always set DEV_RX_OFFLOAD_PTYPE Flags for all the ethdev ports. Right? Rather having any complicated ol_flags or port based parsing. If limit the _contract_ to following, we are good. Right? # when DEV_RX_OFFLOAD_PTYPE is set, mbuf.packet_type will be valid and mbuf.packet_type will have parsed packet type or the negative offload(This contract is pretty clear, I don't think any ambiguity at all) # when DEV_RX_OFFLOAD_NO_PTYPE(something similar) is set, mbuf.packet_type will be invalid. > I think we need either to introduce new ol_flag value (as we usually do for > other RX offloads), > or force PMD to always set ptype value. Setting new ol_flag value may effect performance for existing drivers which don't planning to use this offload and it complicates the application to have additional check based on ol_flag. If you see any corner case with above section, How about just setting as ptype as 0 incase it is not parsed by driver. Actual lookup is the costly one, writing 0 to pytpe is not costly as there are plenty of writes in Rx and it will be write merged(No CPU stall) I did not get the complete picture of "rte_eth_dev_set_supported_ptypes(uint16_t port_id, uint32_t ptype_mask); instead of DEV_RX_OFFLOAD_PTYPE? scheme", Does it help? > Konstantin > > > > > > > > > > > > > > > > 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
