[dpdk-dev] Packet drops during non-exhaustive flood with OVS and 1.8.0

[Andrey Korolyov]

> These patches are to enable DPDK 1.8 only. What 'bulk processing' are you referring to?
> By default there is a batch size of 192 in netdev-dpdk for rx from the NIC - the linked
> patch doesn't change this, just the DPDK version.

Sorry, I referred the wrong part there: bulk transmission, which is
clearly not involved in my case. The idea was that the conditionally
enabling prefetch for rx queues (BULK_ALLOC) may help somehow, but
it`s probably will mask issue instead of solving it directly. By my
understanding, strict drop rule should have a zero impact on a main
ovs thread (and this is true) and work just fine with a line rate
(this is not).

>
> Main things to consider are to isocpu's, pin the pmd thread and keep everything
> on 1 NUMA socket. At 11 mpps without packet loss on that processor I suspect you are
> doing those things already.

Yes, with all tuning improvements I was able to do this, but bare
Linux stack on same machine is able to handle 12Mpps and there are
absolutely no hints of what exactly is being congested.