On Wed, Dec 16, 2015 at 8:11 AM, Tal Abudi <talab...@gmail.com> wrote: > Hi > I have an issue with igb 5.3.2 multi queue on a 2.6.18 machine with I211 > controllers. > When RSS is enabled (2 RX queues) all packets arrive to rx_queue_0 only. > I'm running 2 UDP traffic streams (1.1.1.[10,11]:1024 -> 2.2.2.10:1025). > > With igb 4.3.2 traffic distributed evenly on all queues. > The same configuration works great on a 82580 controller. > > ethtool -S enp5s0 | grep rx_q.*pa > rx_queue_0_packets: 1561216274 > rx_queue_1_packets: 0 > > Is this a known limitations ? > Any tips ? > Thanks !
The problem is that only 2 flows is a fairly small sample set when you only have 2 queues. The odds of all flows ending up on the same CPU are 2 / (2 ^ n). So in the case of 2 flows you have a 50% chance that the hashes end up working out such that they all end up on the same CPU. If you increase the number of flows the likelihood of the flows being distributed increases. Also as you may be aware RSS only uses the IP headers unless you enable them via the command "ethtool -N <ethX> rx-flow-hash udp4 sdfn", however by doing that you can cause out-of-order packets for fragmented flows. - Alex ------------------------------------------------------------------------------ _______________________________________________ E1000-devel mailing list E1000-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/e1000-devel To learn more about Intel® Ethernet, visit http://communities.intel.com/community/wired
