For L2 RSS, I think i40e hardware supports it, which will be enabled soon later.
Regards, Helin > -----Original Message----- > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Vithal S Mohare > Sent: Tuesday, December 23, 2014 5:38 PM > To: Richardson, Bruce > Cc: dev at dpdk.org > Subject: Re: [dpdk-dev] [PATCH RFC 0/3] DPDK ethdev callback support > > Agree. As the mbuf is already received in the rx-q, may not yield great > advantage. > On side note, any plans to support RSS for L2 packets ? > > -----Original Message----- > From: Bruce Richardson [mailto:bruce.richardson at intel.com] > Sent: Tuesday, December 23, 2014 3:00 PM > To: Vithal S Mohare > Cc: dev at dpdk.org > Subject: Re: [dpdk-dev] [PATCH RFC 0/3] DPDK ethdev callback support > > On Tue, Dec 23, 2014 at 04:23:21AM +0000, Vithal S Mohare wrote: > > Hi Bruce, > > > > <snip> > > For example, for a port type that does not support RSS, a callback on RX can > be configured to calculate a hash in software. > > </snip> > > > > Wondering if this callback will also be useful to bridge the gap of no RSS > support for L2 packets. i.e. in the rx call-back handler, can applications > calculate hash and feed it back so that spraying happens based on this? Now, > all pure L2 packets (e.g. arp pkts) comes to rx-q 0 of the 'port'. Adding > callback to [port][rx-q:0] would help? > > > > Thanks, > > -Vithal > > Yes, that could work. The downside is that it is no faster than having an app > do > the calculation itself, it's just perhaps a little easier to work with in the > app. > > /Bruce > > > > > -----Original Message----- > > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Bruce Richardson > > Sent: Monday, December 22, 2014 10:17 PM > > To: dev at dpdk.org > > Subject: [dpdk-dev] [PATCH RFC 0/3] DPDK ethdev callback support > > > > This RFC is for a small addition to the ethdev library, to add in support > > for > callbacks at the RX and TX stages. This allows packet processing to be done on > packets before they get returned to applications using rte_eth_rx_burst call. > > > > Use case: the first use case for this is to enable a consistent set of > > packets > mbufs to be received by applications irrespective of the NIC used to receive > those. For example, for a port type that does not support RSS, a callback on > RX > can be configured to calculate a hash in software. > > Similarly, this mechanism can be used to add other information to mbufs as > they are received, such as timestamps or sequence numbers, without > cluttering up the main packet processing path with checks for whether packets > have these fields filled in or not. > > A second use case is ease of intrumenting existing code. The example > application shows how combining a timestamp insertion callback on RX can be > paired with a latency calculation callback on TX to easily instrument any > application for packet latency. > > A third use case is to potentially extend existing NIC capabilities beyond > > what > is currently supported. For example, where flow director capabilities can > match > up to a certain limit of flows - in the thousands, in the case of NICs using > the > ixgbe driver - a callback can extend this to potentially millions of flows by > using > a software hash table lookup inline for packets that missing the hardware > lookup filters. It would all appear transparent to the packet handling code in > the main application. > > > > Future extensions: in future the ethdev library can be extended to provide a > standard set of callbacks for use by drivers. > > > > For now this patch set is RFC and still needs additional work for creating a > remove function for callbacks and to add in additional testing code. > > Since this adds in new code into the critical data path, I have run some > performance tests using testpmd with the ixgbe vector drivers (i.e. the > fastest, > fast-path we have :-) ). Performance drops due to this patch seems minimal to > non-existant, rough tests on my system indicate a drop of perhaps 1%. > > > > All feedback welcome. > > > > Bruce Richardson (3): > > ethdev: rename callbacks field to intr_cbs > > ethdev: Add in data rxtx callback support > > examples: example showing use of callbacks. > > > > app/test/virtual_pmd.c | 2 +- > > examples/rxtx_callbacks/Makefile | 57 +++++++++ > > examples/rxtx_callbacks/basicfwd.c | 222 > +++++++++++++++++++++++++++++++++ > > examples/rxtx_callbacks/basicfwd.h | 46 +++++++ > > lib/librte_ether/rte_ethdev.c | 103 +++++++++++++-- > > lib/librte_ether/rte_ethdev.h | 125 ++++++++++++++++++- > > lib/librte_pmd_bond/rte_eth_bond_api.c | 2 +- > > 7 files changed, 543 insertions(+), 14 deletions(-) create mode > > 100644 examples/rxtx_callbacks/Makefile create mode 100644 > > examples/rxtx_callbacks/basicfwd.c > > create mode 100644 examples/rxtx_callbacks/basicfwd.h > > > > -- > > 1.9.3 > >
