[dpdk-dev] Load-balancing position field in DPDK load_balancer sample app vs. Hash table

Yerden Zhumabekov e_zhumabekov at sts.kz
Fri Nov 14 17:23:00 CET 2014

I'd like to interject a question here.

In case of flow classification, one might possibly prefer for packets
from the same flow to fall on the same logical core. With this '%' load
balancing, it would require to get the same RSS hash value for packets
with direct (src to dst) and swapped (dst to src) IPs and ports. Am I
correct that hardware RSS calculation cannot provide this symmetry?

14.11.2014 20:44, Ananyev, Konstantin пишет:
> If you have a NIC that is capable to do HW hash computation,
> then you can do your load balancing based on that value.
> Let say ixgbe/igb/i40e NICs can calculate RSS hash value based on different combinations of 
> dst/src Ips, dst/src ports.
> This value can be stored inside mbuf for each RX packet by PMD RX function.
> Then you can do:
> worker_id = mbuf->hash.rss % n_workersl
> That might to provide better balancing then using just one byte value,
> plus should be a bit faster, as in that case your balancer code don't need to touch packet's data.   
> Konstantin


Yerden Zhumabekov
State Technical Service
Astana, KZ

More information about the dev mailing list