[dpdk-users] Drops seems with virtio PMD driver

[Stephen Hemminger]

On Thu, 29 Aug 2019 10:12:27 +0530
Venumadhav Josyula <vjosyula at gmail.com> wrote:

> Hi All,
> 
> We are observing packet drops ~@90Mbs with virtio pmd driver. These packets
> are not been
> queued in the tx descriptors, the function 'rte_eth_tx_burst' is returning
> the less than n.
> 
> So questions are following
> i)  are there any issues seen ?
> 
> Observations in our case :-
> i) packets are dropped and tx packets donot get incremented.
> ii) i) happens for 30 secs after that it recovers.
> iii) After sometime we see this issue in i) & ii) again.
> 
> Any clues / pointers will help.
> 
> Thanks,
> Regards,
> Venu

The number of transmit descriptors is fixed.
If you are producing packets faster than the other consume them then the
transmit descriptor ring gets full. So the problem is probably on the other
side of your virtio. Are you using KVM? Did you enable virtio net acceleration?