On Wednesday, September 07, 2011 10:52:17 am Alexander V. Chernikov wrote: > Hello list! > > (CC'in Jack Vogel since this is intel drivers/hardware specific question) > > There are some techniques for assigning network traffic to different NIC > RX queues (bound to different CPUs/cores). > The main problem for all techniques is avoiding any possible packet > reordering in single flow. > > Most obvious (and most used) are described in Microsoft NDIS driver > specification: > Hashing is done on various tuples like: > * IPv46 src/dst + TCP/UDP src/dst port for TCP/UDP > * IPv46 src/dst for general IPv46 traffic > > igb's have a bit more options like assigning selected ethertype or TCP > SYN to different queue (See section 7.1.1 of 82576EB datasheet) > ixgbe (82599) goes even more far: flow director functionality permits 8K > 'perfect match' filters allowing to select any subset in: > * vlan > * IPv46 src/dst > * L4 proto > * TCP/UDP/SCTP protocol ports > and even 'flexible 2-byte tuple anywhere in the first 64 bytes of the > packet' > > There are other possibilities to assign traffic to different queues in > ixbge like using .1q priority filed (DCB functionality) > More information can be found in sections 7.1.2 (RX queues assignment), > 7.1.2.7(Flow Director), 7.7.1 (DCB) of 82599 datasheet > > However, there are many setups where PC can be used as platform for > routing/dispatching non-IP traffic. > PPPoE server is a typical example. > > People have to do some tricks (link aggregation, non-direct ISR) to get > traffic dispatched by more than single CPU/core, but this much less > efficient. > I'm a bit curious: why some generic hashing mechanism based on something > like 'flexible 2-byte tuple anywhere in the first 64 bytes of the > packet' were not added? > It can be (at least from my point of view) easily based on (for example) > flow director functionality. > > Particularly I'm trying to figure out how can I use all this variety of > filters to get MPLS traffic split to different RX queues. > > Maybe someone can point me to the right direction?
There is another thread on net@ currently talking a good bit about this. It started with a post with a patch to support the traffic steering on ixgbe adapters using sysctls. -- John Baldwin _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
