> -----Original Message----- > From: Yerden Zhumabekov [mailto:e_zhumabekov at sts.kz] > Sent: Friday, November 14, 2014 4:23 PM > To: Ananyev, Konstantin; Kamraan Nasim; dev at dpdk.org > Cc: Yuanzhang Hu > Subject: Re: [dpdk-dev] Load-balancing position field in DPDK load_balancer > sample app vs. Hash table > > 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?
As I remember, it is possible but you have to tweak rss key values. Here is a paper describing how to do that: http://www.ndsl.kaist.edu/~shinae/papers/TR-symRSS.pdf Konstantin > > 14.11.2014 20:44, Ananyev, Konstantin ?????: > > 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 > > -- > Sincerely, > > Yerden Zhumabekov > State Technical Service > Astana, KZ >
